94 rodeo v6 stuttering problems
nickpapa
11-25-2007, 01:04 PM
im trying to help out my girlfriends parents with their 94 rodeo v6 auto.
it has been stuttering/misfiring bad lately. at times it will run fine but will stutter intermittantly.
so far i've replace the fuel filter, plugs, all vacuum lines, cleaned the egr valve, and sprayed carb cleaner by the IMG but the problems are still there. the wires look good but i think they are autozone brand and not sure if that could cause the issue. i've also noticed that the misfiring/stuttering mainly happens under load in drive but not in reverse. although it has stuttered/stalled a few times at a stop.
one thing i did notice is that the pcv valve grommet is ripped at the bottom area where it would site and seat into the valve cover. you can just pull it out with ease. would that cause the car to run like this?
not sure where to go from here so any help is greatly appreciated.
it has been stuttering/misfiring bad lately. at times it will run fine but will stutter intermittantly.
so far i've replace the fuel filter, plugs, all vacuum lines, cleaned the egr valve, and sprayed carb cleaner by the IMG but the problems are still there. the wires look good but i think they are autozone brand and not sure if that could cause the issue. i've also noticed that the misfiring/stuttering mainly happens under load in drive but not in reverse. although it has stuttered/stalled a few times at a stop.
one thing i did notice is that the pcv valve grommet is ripped at the bottom area where it would site and seat into the valve cover. you can just pull it out with ease. would that cause the car to run like this?
not sure where to go from here so any help is greatly appreciated.
srpope80
11-26-2007, 10:31 AM
I would check the wires and make sure it is not arcing even the tiniest little bit. I've seen this alot on all the older cars i've owned/worked on; best way to check is wait until it's dark ouside, and then go and start the car. The darker it is the better. If it's arcing you should see it pretty clearly.
-Scott
-Scott
nickpapa
11-26-2007, 10:49 AM
i will try it again when its dark, but i did spray water over the wires to see if there was arcing but didnt see any arcing or any change in engine idle.
i did notice that the wires were able to come apart or atleast a bit. i noticed it on one wire (going to sparkplug), and i pushed it back together. i didnt try and see if the others did the same but is that normal? i know some wires are rebuildable so i figured these might be as well.
also, as i said above, the pcv valve grommet was ripped at the bottom so it was very easy to just pull up and out. would this cause the problems im having?
i did notice that the wires were able to come apart or atleast a bit. i noticed it on one wire (going to sparkplug), and i pushed it back together. i didnt try and see if the others did the same but is that normal? i know some wires are rebuildable so i figured these might be as well.
also, as i said above, the pcv valve grommet was ripped at the bottom so it was very easy to just pull up and out. would this cause the problems im having?
nickpapa
11-26-2007, 05:09 PM
ok so i just went out to see if the wires were arcing. nothing is arcing, i even sprayed water over the wires to see if there is any arcing and didnt see anything.
i also took the wires off the coil one by one with the car on to see if there is spark. there was spark except for cylinder 6 which had spark but it didnt seem as strong as the others. could that be the problem?
but i do notice that when in drive, it will stutter/misfire, yet in reverse, it doesnt at all??
i also took the wires off the coil one by one with the car on to see if there is spark. there was spark except for cylinder 6 which had spark but it didnt seem as strong as the others. could that be the problem?
but i do notice that when in drive, it will stutter/misfire, yet in reverse, it doesnt at all??
trooperbc
11-27-2007, 12:26 AM
the thing is, as you probably know or are finding out, your symptoms could be caused by just about anything from fuel system, to smog components, to ignition system, to engine mechanical, etc, etc.
...i also took the wires off the coil one by one with the car on to see if there is spark. there was spark except for cylinder 6 which had spark but it didnt seem as strong as the others. could that be the problem? could be, and it could be intermittent, especially under load, but i'd think just one cylinder acting a bit weak wouldn't cause the symptom as described.
but i do notice that when in drive, it will stutter/misfire, yet in reverse, it doesnt at all?? this sounds either coincidental, or perhaps a result of the different gearing giving a different affect.
also, as i said above, the pcv valve grommet was ripped at the bottom so it was very easy to just pull up and out. would this cause the problems im having? again maybe. it ought to be tight, otherwise the leak will affect engine especially at idle. just seal it temp with some cloth and/or tape and see if that affects a change for you.
for no particular reason, i'm thinking egr system. when you cleaned it, did you get that thin little port that looks like a vacuum line to the backpressure transducer (BPT). make sure it's clean and fully clear.
and the plugs, what condition were they? and was there oil in the sparkplug tubes? and the ignition wire set, sounds a bit shoddy(?). definitely suggest a quality set like oem, and if you have oil in the tubes, get the kind that has larger diameter connectors with built in seal rings to seal the oil from shorting out the plugs.
is the stuttering limited to cold or warmed-up driving? any other indicators that might point to the O2 sensor?
finally, back to the ignition, it's possible a coil or more is going. they do go defective idividually, and i've had one short, arc, intermittent (almost) nonexistent at idle but underload a real and growing problem. was able to diagnose using the darkofnight trick and use of cheapo ignition short tester from bigboxstore. also used an inductive timing light to spot intermittent firing. each coil fires two cylinders, the #'s are marked on the coil terminals.
finally2, on the fuel front, check the fuel pressure regulator. one easy check is to pull the vacuum hose off, if there is fuel in there at that port, then the fuel pressure regulator needs replacing.
//bc
...i also took the wires off the coil one by one with the car on to see if there is spark. there was spark except for cylinder 6 which had spark but it didnt seem as strong as the others. could that be the problem? could be, and it could be intermittent, especially under load, but i'd think just one cylinder acting a bit weak wouldn't cause the symptom as described.
but i do notice that when in drive, it will stutter/misfire, yet in reverse, it doesnt at all?? this sounds either coincidental, or perhaps a result of the different gearing giving a different affect.
also, as i said above, the pcv valve grommet was ripped at the bottom so it was very easy to just pull up and out. would this cause the problems im having? again maybe. it ought to be tight, otherwise the leak will affect engine especially at idle. just seal it temp with some cloth and/or tape and see if that affects a change for you.
for no particular reason, i'm thinking egr system. when you cleaned it, did you get that thin little port that looks like a vacuum line to the backpressure transducer (BPT). make sure it's clean and fully clear.
and the plugs, what condition were they? and was there oil in the sparkplug tubes? and the ignition wire set, sounds a bit shoddy(?). definitely suggest a quality set like oem, and if you have oil in the tubes, get the kind that has larger diameter connectors with built in seal rings to seal the oil from shorting out the plugs.
is the stuttering limited to cold or warmed-up driving? any other indicators that might point to the O2 sensor?
finally, back to the ignition, it's possible a coil or more is going. they do go defective idividually, and i've had one short, arc, intermittent (almost) nonexistent at idle but underload a real and growing problem. was able to diagnose using the darkofnight trick and use of cheapo ignition short tester from bigboxstore. also used an inductive timing light to spot intermittent firing. each coil fires two cylinders, the #'s are marked on the coil terminals.
finally2, on the fuel front, check the fuel pressure regulator. one easy check is to pull the vacuum hose off, if there is fuel in there at that port, then the fuel pressure regulator needs replacing.
//bc
nickpapa
11-27-2007, 06:37 PM
thank you very much for the reply trooperbc i appreciate it. here are some updates from today:
so i bought 3 new coils from autozone, swapped them in and nothing changed. luckily autozone let me return them.
i also changed the pcv valve and grommet as the old grommet was ripped, and nothing changed again.
you asked if the symptoms change when hot or cold and the answer is no they dont change. since you said that, i decided to pull the fuse for the o2 sensor and nothing changed again. not sure if that fuse controls all 4 o2 sensors but regardless nothing changed.
so since i live on a hill, i thought i'd try reversing up it a good amount to see if it will stutter/misfire and it did not. once i put it in drive (even going down hill) symptoms came right back.
also the valve cover gaskets are shot as there is oil on the wires. but the wires i have i think are the ones that seal to not allow oil (as trooperbc explained it). the wires on there now look like these
http://www.thepartsbin.com/catalog/images/alloem_products/images/WORLDPAC/W01331619315PST.JPG
i also noticed that there is an occasional pop coming from the airbox (im almost positive its the airbox) while it is stuttering/misfiring.
as far as the egr valve, i took the one that is by the firewall which says egr on one side and vsv (could be wrong) on the other side. i just sprayed some carb cleaner into it and had some black stuff come out of it. not sure what you mean by transducer, this is the first time working on an isuzu so im not to sure on that term.
other than that, i had my brother put it in drive, hold the brake and give a little gas with the hood up so i can see if maybe there will be arcing that way but again i didnt see anything.
so atleast now we can narrow it down to not being
fuel filter
plugs
coils
pcv valve
i also spoke with my girlfriends father and he said when he bought the car it acted like this (but not as bad) brought it to a mechanic, he said he couldnt figure it out and gave it back to him and apparantly it drove fine for about 2 months until now.
so i bought 3 new coils from autozone, swapped them in and nothing changed. luckily autozone let me return them.
i also changed the pcv valve and grommet as the old grommet was ripped, and nothing changed again.
you asked if the symptoms change when hot or cold and the answer is no they dont change. since you said that, i decided to pull the fuse for the o2 sensor and nothing changed again. not sure if that fuse controls all 4 o2 sensors but regardless nothing changed.
so since i live on a hill, i thought i'd try reversing up it a good amount to see if it will stutter/misfire and it did not. once i put it in drive (even going down hill) symptoms came right back.
also the valve cover gaskets are shot as there is oil on the wires. but the wires i have i think are the ones that seal to not allow oil (as trooperbc explained it). the wires on there now look like these
http://www.thepartsbin.com/catalog/images/alloem_products/images/WORLDPAC/W01331619315PST.JPG
i also noticed that there is an occasional pop coming from the airbox (im almost positive its the airbox) while it is stuttering/misfiring.
as far as the egr valve, i took the one that is by the firewall which says egr on one side and vsv (could be wrong) on the other side. i just sprayed some carb cleaner into it and had some black stuff come out of it. not sure what you mean by transducer, this is the first time working on an isuzu so im not to sure on that term.
other than that, i had my brother put it in drive, hold the brake and give a little gas with the hood up so i can see if maybe there will be arcing that way but again i didnt see anything.
so atleast now we can narrow it down to not being
fuel filter
plugs
coils
pcv valve
i also spoke with my girlfriends father and he said when he bought the car it acted like this (but not as bad) brought it to a mechanic, he said he couldnt figure it out and gave it back to him and apparantly it drove fine for about 2 months until now.
nickpapa
11-28-2007, 02:43 PM
any help is greatly appreciated guys!
trooperbc
11-29-2007, 02:24 AM
....
so since i live on a hill, i thought i'd try reversing up it a good amount to see if it will stutter/misfire and it did not. once i put it in drive (even going down hill) symptoms came right back. well i guess you gotta go with what you're finding out, whether it makes a lot of sense or not. there really isn't anything engine or computer wise that cares whether you're going forward or reverse -- except the the trans inputs, of course. exactly where to go with that, i'm not sure from here, and at this hour.
first, i can assume no problems in N neutral?
if it were happening to me, and i noticed this forward/reverse thing, i'd guess i'd start looking at the trans mode switch system, which is what tells the electronics part of the transmission what gear you have selected. symptoms of a bad or problem switch are usually quite different, however.
how about, crawl under there and follow the wiring and see what you can see. the wires are right up there by the exhaust pipes and if they got dislodged maybe you've go a singed wire or two. the mode switch is on the outside of the trans, drivers side, where the the gear selector arms are.
that's where i'd start anyway.
mmmm... or
[quote]....brought it to a mechanic, he said he couldnt figure it out and gave it back to him and apparantly it drove fine for about 2 months until now.
i can't figure it out ! [see if that'll last 2 months....]
//bc
so since i live on a hill, i thought i'd try reversing up it a good amount to see if it will stutter/misfire and it did not. once i put it in drive (even going down hill) symptoms came right back. well i guess you gotta go with what you're finding out, whether it makes a lot of sense or not. there really isn't anything engine or computer wise that cares whether you're going forward or reverse -- except the the trans inputs, of course. exactly where to go with that, i'm not sure from here, and at this hour.
first, i can assume no problems in N neutral?
if it were happening to me, and i noticed this forward/reverse thing, i'd guess i'd start looking at the trans mode switch system, which is what tells the electronics part of the transmission what gear you have selected. symptoms of a bad or problem switch are usually quite different, however.
how about, crawl under there and follow the wiring and see what you can see. the wires are right up there by the exhaust pipes and if they got dislodged maybe you've go a singed wire or two. the mode switch is on the outside of the trans, drivers side, where the the gear selector arms are.
that's where i'd start anyway.
mmmm... or
[quote]....brought it to a mechanic, he said he couldnt figure it out and gave it back to him and apparantly it drove fine for about 2 months until now.
i can't figure it out ! [see if that'll last 2 months....]
//bc
nickpapa
11-29-2007, 07:48 AM
thanks for the reply trooperbc.
i have a little bit of an update from yesterday, i decided to take a spin in it right when i got home from work where i know the engine was cold. i started it and just started to drive. it hesitated a very tiny bit and all of a sudden it was driving normal with no problems at all. as soon as the engine warmed up a little here come the bucking/stuttering again. so i was thinking maybe o2 sensor? i am going to do the same thing when i get home today and see if it acts the same.
as far as the trans switch, i think that is a good idea but as you said the symptoms shouldn't be this way. so i think your right on how it might not be that because even while stuttering/bucking, i can feel the trans switching gears according to engine speed.
i will also try to reverse when the truck is fully warmed up and see if it does it.
maybe a bad ground? anybody have a diagram of where the grounds run?
again, thank you trooperbc for the help
i have a little bit of an update from yesterday, i decided to take a spin in it right when i got home from work where i know the engine was cold. i started it and just started to drive. it hesitated a very tiny bit and all of a sudden it was driving normal with no problems at all. as soon as the engine warmed up a little here come the bucking/stuttering again. so i was thinking maybe o2 sensor? i am going to do the same thing when i get home today and see if it acts the same.
as far as the trans switch, i think that is a good idea but as you said the symptoms shouldn't be this way. so i think your right on how it might not be that because even while stuttering/bucking, i can feel the trans switching gears according to engine speed.
i will also try to reverse when the truck is fully warmed up and see if it does it.
maybe a bad ground? anybody have a diagram of where the grounds run?
again, thank you trooperbc for the help
FL 3.2L
11-29-2007, 04:19 PM
It does sound sensor related. As soon as the engine gets warmed up it starts relying on several sensors to adjust the mixture. MAP sensor, O2 sensors, MAF, temp sensor, or something similar?
FL 3.2L
11-29-2007, 04:25 PM
Has anybody put a scanner on it yet?
How about pulling plugs and checking their condition?
How about pulling plugs and checking their condition?
nickpapa
11-29-2007, 04:38 PM
plugs are brand new. if you look a couple posts up i listed what was replaced. so far this is what has been replaced/looked at:
Plugs
Vacuum Lines
PCV Valve
Fuel Filter
All 3 Coils
i took it for another drive when i got home from work. when it was cold, it was drivable but still had a stutter here and there, once it warmed up, it was like pulling teeth to get the thing to move. but again when it was warmed up, i reverse all the way up my hill with not one stutter. freakin crazy. i dont get it
im going to replace the o2 sensor on saturday. hopefully that works but with this whole reverse thing it makes it so much more confusing.
also when in drive at idle it will stutter and want to stall, and if i put it in neutral it will idle perfect.
Plugs
Vacuum Lines
PCV Valve
Fuel Filter
All 3 Coils
i took it for another drive when i got home from work. when it was cold, it was drivable but still had a stutter here and there, once it warmed up, it was like pulling teeth to get the thing to move. but again when it was warmed up, i reverse all the way up my hill with not one stutter. freakin crazy. i dont get it
im going to replace the o2 sensor on saturday. hopefully that works but with this whole reverse thing it makes it so much more confusing.
also when in drive at idle it will stutter and want to stall, and if i put it in neutral it will idle perfect.
FL 3.2L
11-30-2007, 04:56 PM
Read it all.
If you have a cylinder missing, it will foul a new plug and you can see it if you pull it.
If you have a cylinder missing, it will foul a new plug and you can see it if you pull it.
trooperbc
11-30-2007, 07:59 PM
thanks for the reply trooperbc.
i have a little bit of an update from yesterday, i decided to take a spin in it right when i got home from work where i know the engine was cold. i started it and just started to drive. it hesitated a very tiny bit and all of a sudden it was driving normal with no problems at all. as soon as the engine warmed up a little here come the bucking/stuttering again. so i was thinking maybe o2 sensor? i am going to do the same thing when i get home today and see if it acts the same.
as far as the trans switch, i think that is a good idea but as you said the symptoms shouldn't be this way. so i think your right on how it might not be that because even while stuttering/bucking, i can feel the trans switching gears according to engine speed.
i will also try to reverse when the truck is fully warmed up and see if it does it.
maybe a bad ground? anybody have a diagram of where the grounds run?
again, thank you trooperbc for the help okay, i've been thinking about this off and on today. here's my latest take:
iirc.....there have been a number of posts here or other sites where irratic and poor running ended up being traced to a messed up brake light. they fixed the brake light problem (might even have been a burnt out bulb; remember maybe a ground issue in another), they fixed that and fixed their driveability problems. i also believe trailer wiring connectors have also caused such problems. why? electricity does wondrous things and backs up places when it stymied, especially it seems with isuzu's.
now, in your case, maybe a clue is that all is well in reverse. that mode switch is really a triple-threat device 1. instructing the trans electronics on gear selection 2. neutral safety switch (will start only in N or D) AND THREE 3. the backup light switch. maybe, just maybe, when you are in reverse, the electrical circuit is completed back there, with the electrons going to the backup lights. without the backup lites working, the electricity is looking to complete its deviant circuit some other way, which ends up causing your problem(s).
anyway, that's my big idea. check the rear light assemblies, bulbs, contacts, etc, and trailer light wiring/plug, too.
//bc
i have a little bit of an update from yesterday, i decided to take a spin in it right when i got home from work where i know the engine was cold. i started it and just started to drive. it hesitated a very tiny bit and all of a sudden it was driving normal with no problems at all. as soon as the engine warmed up a little here come the bucking/stuttering again. so i was thinking maybe o2 sensor? i am going to do the same thing when i get home today and see if it acts the same.
as far as the trans switch, i think that is a good idea but as you said the symptoms shouldn't be this way. so i think your right on how it might not be that because even while stuttering/bucking, i can feel the trans switching gears according to engine speed.
i will also try to reverse when the truck is fully warmed up and see if it does it.
maybe a bad ground? anybody have a diagram of where the grounds run?
again, thank you trooperbc for the help okay, i've been thinking about this off and on today. here's my latest take:
iirc.....there have been a number of posts here or other sites where irratic and poor running ended up being traced to a messed up brake light. they fixed the brake light problem (might even have been a burnt out bulb; remember maybe a ground issue in another), they fixed that and fixed their driveability problems. i also believe trailer wiring connectors have also caused such problems. why? electricity does wondrous things and backs up places when it stymied, especially it seems with isuzu's.
now, in your case, maybe a clue is that all is well in reverse. that mode switch is really a triple-threat device 1. instructing the trans electronics on gear selection 2. neutral safety switch (will start only in N or D) AND THREE 3. the backup light switch. maybe, just maybe, when you are in reverse, the electrical circuit is completed back there, with the electrons going to the backup lights. without the backup lites working, the electricity is looking to complete its deviant circuit some other way, which ends up causing your problem(s).
anyway, that's my big idea. check the rear light assemblies, bulbs, contacts, etc, and trailer light wiring/plug, too.
//bc
trooperbc
11-30-2007, 08:36 PM
....AND check out focus2win's neat little trick of pulling fuses....maybe there's something in it for you.....
http://www.automotiveforums.com/vbulletin/showthread.php?p=5033807#post5033807
//bc
http://www.automotiveforums.com/vbulletin/showthread.php?p=5033807#post5033807
//bc
nickpapa
12-01-2007, 08:16 AM
thank you trooperbc i will definitely do those random tries that the focus guy did.
i was trying to think out of the box as well and was thinking MAYBE the clip is not totally in on the o2 sensor and when its hot, it runs like crap because its not reading anything, and when i put it in reverse, since the front dips down, it pushes the clip together making contact and the o2 starts functioning again? its a long shot but i guess ill just have to take a look today.
i was trying to think out of the box as well and was thinking MAYBE the clip is not totally in on the o2 sensor and when its hot, it runs like crap because its not reading anything, and when i put it in reverse, since the front dips down, it pushes the clip together making contact and the o2 starts functioning again? its a long shot but i guess ill just have to take a look today.
nickpapa
12-01-2007, 10:48 AM
ok here are the updates from today.
replaced the o2 sensor and nothing changed. i then figure out which egr valve i should have cleaned and cleaned it with some carb cleaner. still nothing change.
i then tried the "take every fuse out" idea and nothing changed again. looked for hitch wires but it doesnt even have a hitch. what i am 300% sure about is that it will ONLY act like this in all gears that go forward (D, 2, 3). in reverse it will drive great with no problems whatsoever. if only it was legal to drive in reverse everywhere we'd be all set.
i also disconnected the battery for a couple minutes thinking maybe it will reset itself or something but nothing changed again.
this thing is driving me nuts. but what i am totally sure is that it will only act like this in gears that move forward when the car is hot. when its cold its drivable. still stutters at idle (in D), but it will get you where you need to go. once it warms up though its a mess.
So now we've crossed out:
o2 sensor
PCV valve
spark plugs
vacuum lines
fuel filter
fuse trick
not sure where to go from here
replaced the o2 sensor and nothing changed. i then figure out which egr valve i should have cleaned and cleaned it with some carb cleaner. still nothing change.
i then tried the "take every fuse out" idea and nothing changed again. looked for hitch wires but it doesnt even have a hitch. what i am 300% sure about is that it will ONLY act like this in all gears that go forward (D, 2, 3). in reverse it will drive great with no problems whatsoever. if only it was legal to drive in reverse everywhere we'd be all set.
i also disconnected the battery for a couple minutes thinking maybe it will reset itself or something but nothing changed again.
this thing is driving me nuts. but what i am totally sure is that it will only act like this in gears that move forward when the car is hot. when its cold its drivable. still stutters at idle (in D), but it will get you where you need to go. once it warms up though its a mess.
So now we've crossed out:
o2 sensor
PCV valve
spark plugs
vacuum lines
fuel filter
fuse trick
not sure where to go from here
trooperbc
12-01-2007, 09:42 PM
ok...i take it one of the fuses you removed is for the backup light....
now, disconnect the mode switch, follow the wires to the switch. i believe your connector is right there up from the switch. drive it manually (the electronics won't work). see if that gets you any change.
//bc
now, disconnect the mode switch, follow the wires to the switch. i believe your connector is right there up from the switch. drive it manually (the electronics won't work). see if that gets you any change.
//bc
nickpapa
12-02-2007, 01:46 AM
i will do that trooperbc. just one question, where is the mode switch located? is it on the trans itself or under the center console?
by the way, i removed every fuse in the dash, and all the fuses in the engine bay that were for any type of accessory.
by the way, i removed every fuse in the dash, and all the fuses in the engine bay that were for any type of accessory.
trooperbc
12-03-2007, 12:53 AM
the mode switch is around the gearselector shaft on the left(driver's) side of the transmission where the linkage from the shifter attaches. (the bmw has the switch up at the shifter, btw).
//bc
//bc
nickpapa
12-03-2007, 05:44 PM
so i think i found the mode switch. its the part that kinda looks like a slice of pizza connected directly to the linkage?
well if so, i tried following the wires and it looks like they go up along the side of the radiator fan (drivers side). from there i cant see where it goes. i took the front portion of the airbox out and saw 2 clips going to the headlights and one that was part of the main harness. i took the connector off that was part of the main harness, and the car wouldn't start. any idea exactly where the connector is for the mode switch?
well if so, i tried following the wires and it looks like they go up along the side of the radiator fan (drivers side). from there i cant see where it goes. i took the front portion of the airbox out and saw 2 clips going to the headlights and one that was part of the main harness. i took the connector off that was part of the main harness, and the car wouldn't start. any idea exactly where the connector is for the mode switch?
trooperbc
12-03-2007, 11:33 PM
so i think i found the mode switch. its the part that kinda looks like a slice of pizza connected directly to the linkage?
well if so, i tried following the wires and it looks like they go up along the side of the radiator fan (drivers side). from there i cant see where it goes. i took the front portion of the airbox out and saw 2 clips going to the headlights and one that was part of the main harness. i took the connector off that was part of the main harness, and the car wouldn't start. any idea exactly where the connector is for the mode switch?
this illustration is from the isuzu online parts site www.myisuzuparts.com (http://www.myisuzuparts.com) a good resource especially if you don't have the factory manual(s) from www.helminc.com (http://www.helminc.com) very pricey but excellent overall.
http://www.myisuzuparts.com/images/Rodeo%2091-97/Print/2-49a.gif
#61 is the switch (with wire and connector); #102 is the metal cover that you see. different models and years have different length wire looms so the connector is in different places. on my 1992 trooper it has a very long loom that ends in the connector under the air cleaner box, clipped into the front tin behind the headlights, there are 3 connectors, the modeswitch connector is the bottom one and i had to remove the other two first (of course!). to get to it i had to remove the aircleaner box topandbottom. others have a short loom with the connection right at the trans up from the switch.
//bc
well if so, i tried following the wires and it looks like they go up along the side of the radiator fan (drivers side). from there i cant see where it goes. i took the front portion of the airbox out and saw 2 clips going to the headlights and one that was part of the main harness. i took the connector off that was part of the main harness, and the car wouldn't start. any idea exactly where the connector is for the mode switch?
this illustration is from the isuzu online parts site www.myisuzuparts.com (http://www.myisuzuparts.com) a good resource especially if you don't have the factory manual(s) from www.helminc.com (http://www.helminc.com) very pricey but excellent overall.
http://www.myisuzuparts.com/images/Rodeo%2091-97/Print/2-49a.gif
#61 is the switch (with wire and connector); #102 is the metal cover that you see. different models and years have different length wire looms so the connector is in different places. on my 1992 trooper it has a very long loom that ends in the connector under the air cleaner box, clipped into the front tin behind the headlights, there are 3 connectors, the modeswitch connector is the bottom one and i had to remove the other two first (of course!). to get to it i had to remove the aircleaner box topandbottom. others have a short loom with the connection right at the trans up from the switch.
//bc
nickpapa
12-04-2007, 07:50 AM
ok so from the pic it looks like i definitley found the correct part. ill have to take another look at it tonight when i get home from work.
it sounds like mine is long like your troopers and goes up to the same spot. i will have to take another look today and try to find it. maybe ill remove the whole airbox like you did instead of just the front portion. but i also had to take off the 2 clips for the headlights to get to the third clip that i thought was for the mode switch.
ill keep you updated.
it sounds like mine is long like your troopers and goes up to the same spot. i will have to take another look today and try to find it. maybe ill remove the whole airbox like you did instead of just the front portion. but i also had to take off the 2 clips for the headlights to get to the third clip that i thought was for the mode switch.
ill keep you updated.
nickpapa
12-04-2007, 05:06 PM
ok have some updates.
i found the correct clip, unclipped it and again nothing changed. reverses no problem, gets really bad once the car is hot.
any other ideas?
im thinking maybe there is an issue with the ecu? but then why would it only do it once it is warm? i just dont get it
i found the correct clip, unclipped it and again nothing changed. reverses no problem, gets really bad once the car is hot.
any other ideas?
im thinking maybe there is an issue with the ecu? but then why would it only do it once it is warm? i just dont get it
FL 3.2L
12-04-2007, 06:38 PM
Scan it for codes.
nickpapa
12-04-2007, 06:44 PM
will it blink codes even if the engine light isnt on?
FL 3.2L
12-04-2007, 07:00 PM
I forgot that you are OBDI. I'm OBDII and I think I can get codes without a CEL.
trooperbc
12-04-2007, 09:50 PM
ok have some updates.
i found the correct clip, unclipped it and again nothing changed. reverses no problem, gets really bad once the car is hot.
any other ideas?
im thinking maybe there is an issue with the ecu? but then why would it only do it once it is warm? i just dont get it well there are a number of possibilities that rear their ugly heads when warm but not cold
BUT -- THEY DON'T ONLY DO IT IN FORWARD GEARS AND STOP WHEN PUT IN REVERSE.
some of those temp related issues include egr system, 02 system, and the CTS coolant temperature sensor (which is what tells the computer what temp the coolant temp is (different from switch that operates the dash temp gauge), and the temp switch for the intake manifold air.
when cold, the computer operates from predetermined values, then when things are warmed up, it accepts values from the 02 sensor, and allows the egr system to operate.
there is also the issue of the intake manifold gasket, but that is usually an issue on later years.
these things above, 02 sensor circuit, egr system, etc would have been suggested long ago by multiple replies IF your sysmptoms didn't go away depending on gear selection. but maybe you'd better start down those tracks.
will it blink codes even if the engine light isnt on? yes, codes are stored. obdI is not as precise or prolific in results as obdII diagnostics of 1996 and on. on the other hand, you can read your own codes simply by jumpering a connector and counting the flashes of the CEL. do you know how to do that?
//bc
i found the correct clip, unclipped it and again nothing changed. reverses no problem, gets really bad once the car is hot.
any other ideas?
im thinking maybe there is an issue with the ecu? but then why would it only do it once it is warm? i just dont get it well there are a number of possibilities that rear their ugly heads when warm but not cold
BUT -- THEY DON'T ONLY DO IT IN FORWARD GEARS AND STOP WHEN PUT IN REVERSE.
some of those temp related issues include egr system, 02 system, and the CTS coolant temperature sensor (which is what tells the computer what temp the coolant temp is (different from switch that operates the dash temp gauge), and the temp switch for the intake manifold air.
when cold, the computer operates from predetermined values, then when things are warmed up, it accepts values from the 02 sensor, and allows the egr system to operate.
there is also the issue of the intake manifold gasket, but that is usually an issue on later years.
these things above, 02 sensor circuit, egr system, etc would have been suggested long ago by multiple replies IF your sysmptoms didn't go away depending on gear selection. but maybe you'd better start down those tracks.
will it blink codes even if the engine light isnt on? yes, codes are stored. obdI is not as precise or prolific in results as obdII diagnostics of 1996 and on. on the other hand, you can read your own codes simply by jumpering a connector and counting the flashes of the CEL. do you know how to do that?
//bc
nickpapa
12-05-2007, 07:47 AM
yeah i think i remember reading on here how to do that. i will search again about it just to be safe.
as for egr system and o2, i cleaned the egr, and replaced the o2. i also disconnected the o2 to see if there would be any change but nothing changed. so maybe the ecu is the culprit?
does this year have a dedicated ecu i can take a look at? if so can you tell me where it is?
i remember working on a vw passat once and it was throwing all kinds of codes that were very random. it turned out anti-freeze somehow ended up into the ecu area and was causing all of these wierd issues. cleaned it up and it was fine. not saying this could be the problem but maybe something similar?
UPDATE: so i took a look at the ecu. didn't see anything unusual with the wires or anything so i thought i'd try and check the codes. As per a thread that I found on here, there should be an unused 3 prong connector right by the ecu. well i could not find that 3 prong connector and could only find 3 unused connectors. 1 connector was 2 prong with 2 wires coming out of it, the other was 2 prong with 4 wires coming out of it, and the last one was 1 prong with 1 wire. here are some pics, is one of these the ones i am supposed to test with?
http://uploader.meinwirt.com/files/52/ecu2.jpg
http://uploader.meinwirt.com/files/52/ecu1.jpg
as for egr system and o2, i cleaned the egr, and replaced the o2. i also disconnected the o2 to see if there would be any change but nothing changed. so maybe the ecu is the culprit?
does this year have a dedicated ecu i can take a look at? if so can you tell me where it is?
i remember working on a vw passat once and it was throwing all kinds of codes that were very random. it turned out anti-freeze somehow ended up into the ecu area and was causing all of these wierd issues. cleaned it up and it was fine. not saying this could be the problem but maybe something similar?
UPDATE: so i took a look at the ecu. didn't see anything unusual with the wires or anything so i thought i'd try and check the codes. As per a thread that I found on here, there should be an unused 3 prong connector right by the ecu. well i could not find that 3 prong connector and could only find 3 unused connectors. 1 connector was 2 prong with 2 wires coming out of it, the other was 2 prong with 4 wires coming out of it, and the last one was 1 prong with 1 wire. here are some pics, is one of these the ones i am supposed to test with?
http://uploader.meinwirt.com/files/52/ecu2.jpg
http://uploader.meinwirt.com/files/52/ecu1.jpg
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