Idle?? Transmission??

[msdz]

Alright, been a long time since I have had to come on here and ask some questions. So first one is... My '94 JGC Limited with the 5.2L has a weird idle to it when it gets warm outside, like above 75*F and gets worse when it gets about 85*F. I can be sitting still and my RPM's will go from about 750 to almost nothing and the engine almost dies. It hasn't yet though. Also when it acts like this it spits and sputters till I start actually driving a lot faster or rev the engine up after putting the tranny in neutral.
Quite a few people claim it is in the fuel pump or pressure regulator, I have my doubts though. I am leaning more to a sensor. Maybe the O2 senor cause I also started back with the check engine light with a code 52. I have a new one on order, so will try it when I get it. BUT what else could be causing the bad idle? I have replaced almost all my sensors except for MAP and O2 as of right now. I was thinking maybe vacuum leak or bad plug wire. Maybe even distributor, rotor, coil? I plan on checking all of these but anything else I should check?

Transmission question now. What causes the transmission not to engage when put in "Drive" but works fine when placed in "1" or "2". After I start driving I can put the selector back into "Drive" and all is well. I was told it was a bad bearing in the transmission and that it may last 6 months or maybe even a year but the tranny will end up leaving me sitting. Any thoughts on this one??
One more question about the tranny, I want to actually put a 5 speed in the JGC. I know, big headache doing so but what transmission would I need and will a Dodge Dakota clutch and brake pedals work or where could I possibly find the pedal assembly from a '93 model that came out with the standard AX15 transmission? I know the transmission won't work but figured I may get the pedal assembly, then I thought maybe a Dodge truck that had the 318(5.2L) engine with a 5 speed would bolt right up with no problems.

Then the next question is... if I can/did put a standard in the JGC would I get all kinds of check engine codes or whatever? I am sure someone has done it and can maybe give me a clue. I also thought of getting a floor mount hydraulic clutch pedal and then cutting down the brake pedal if I can't find the actually assembly. Was thinking the Dodge Dakota pedals should work though.

[Bob D.]

For the idle I would rule out the fuel pump also since it runs fine as soon as you open the throttle. On the top of my list would be the IAC, second the TPS. I wouldn't rule out the O2 sensor. Since it's worse when at warmer temps does it coincide with the a/c turning on?
The transmission issue could be the valve body.

Have you checked for engine and transmission codes lately?

No idea on the tranny swap.

[msdz]

OK, tranny codes?? On a '94 they have these? Have no idea how to acquire them if it has a computer to the tranny, please tell me how to get them if a computer controls the tranny on a '94 model.
Ok, I have replaced with new the TPS, the IAC motor, and I have not yet put the O2 sensor on yet but just received it today. I figured I would maybe do that tomorrow. Engine code had came on and went off for a long time till right before I made the post above. I checked the engine code and it was 52.
Anyway, the engine light seems to come on when I get gas from a certain gas station. So it may be something in that gas that causes this problem?? Still replacing the O2 sensor anyway since I have it and the Jeep is probably due for a new one anyway. Yes, the engine light also seems to coincide with the outside temperature AND sometimes running the A/C but A/C does not have to be on all the time for the Jeep to run the way it does. It just seems to run worse when the A/C is on, sometimes almost actually dying in traffic.

Now, doing some searching around I was thinking that maybe the New Venture NV3500 transmission would work behind the 5.2L engine(since they came out in Dodge and GM light duty trucks)? As for pedals assembly I was thinking I could cut down the brake pedal to resemble a normal manual brake pedal and then go to a racing shop down the road and get a floor mount hydraulic clutch assembly. A buddy told me this is what he does when he is piecing together vehicles and is the one that actually gave me the idea of the floor mount clutch. Might not look real pretty but it would work...or so I am thinking and told it would. The only issues would be speedometer connections and computer engine codes/transmission codes...maybe?!?!

One of many websites that give some info on the NV3500 tranny. http://dodgeram.org/tech/transmission/nv3500_spec.htm Only thing would be WHAT TRANSFER CASE THEN, lol.

[Bob D.]

OK, tranny codes?? On a '94 they have these? Have no idea how to acquire them if it has a computer to the tranny, please tell me how to get them if a computer controls the tranny on a '94 model.

On the 1999s up the key on/off will display most transmission codes, before that year you may need an OBDII tool to retrieve the tranny codes.

Code 52 - The info I have states:
A rich air/fuel mixture has been indicated by an abnormally rich correction factor.

See how it goes after the O2 sensor is replaced.

[msdz]

So far(knock on wood) I believe the O2 sensor has solved my problems with the rough idle. I have not had time to really drive it for any distance or time since I replaced the O2 sensor and not in hot weather, which is when I really noticed the rough idle problems.

Tranny codes and OBDII? I have a 1994 model, that was before the OBDII. But just to let you know I have a scanner that can read OBDI & II. I have talked to a few people and they said my model year does not have any type of computer for the transmission. Which this should be real good for me if this is so if I am planning on trying to put a manual transmission in the Jeep. I am going to start looking in local junkyards for a manual transmission and transfer case now. I believe I can get it to work right if I make sure I have everything before I start tearing it all down.

[Bob D.]

Sorry about that, you're right of course - no tranny codes on early model Jeeps.

But just to let you know I have a scanner that can read OBDI & II.

Very handy to have, with software and adapter cables some OBD II tools are backward compatible with OBD I vehicles.

[msdz]

When I bought the Jeep I bought the scanner. Figured I wanted one just in case and it has already paid for itself by scanning friends vehicles, I will loan it to them for a small fee. I paid $280 which to me was worth it. I also wanted to make sure I could scan and read almost all vehicles with just one scanner. It is an AutoXray if you are wondering.

Anyway, I have replaced all sensors but 2, the MAP semsor and the air temperature sensor on the intake. I was driving about 2 nights ago and it started with the up and down idle, about a 200 RPM difference. I really have no ideas left except that there maybe a vacuum leak somewhere or dirty injectors? Which if it was the injectors it looks like it would be worse at higher speeds. I was thinking of getting some WD40 and some injector cleaner to add to my fuel. The WD40 is so I can spray around the vacuum lines to see if there is any increase or decrease in RPM's while sitting still.
Could a cam semsor or crank sensor cause this to happen? I have not replaced them YEt and kinda hoping it isn't them. A tight fit with the 5.2L in there and not exactly sure how to go about replacing them. I do not have any engine light coming on at all now though. Reason I was thinking it may be a vacuum leak instead of another sensor.

[Bob D.]

Still sounds like a sensor - a vacuum leak usually doesn't cause the RPMs to fluctuate up and down.

[msdz]

Hmmm, wonder what sensor it could be? Like I said I haven't replaced the air temperature sensor or the MAP sensor. My "Check Engine" light is off now and all seems to be fine except the RPM fluctuation. Will or can the crank sensor or cam sensor cause my problem? I also scanned for codes and didn't get any, which I knew I wouldn't cause no "Check Engine" light is on.

[legalfee]

Ignition coil cured my rough idle. Just don't get one at Auto Zone. I did and it went out completely 8 months later.

[msdz]

I had thought maybe it could also be dirty fuel injectors? BUT then I was thinking it runs way to good at higher speeds, no hesitation or anything. I can run 100 MPH down the road and it feels really smooth running then. A dirty injector would still cause it to have that rough feel at higher speeds, wouldn't it?

[msdz]

Well, just out of the blue yesterday the Jeep had the check engine light come on again. I have not had time to check it yet but plan on it in a little while. I have noticed that the Jeep seems to be running really rich too. So, it makes me think the O2 senor I bought was crap and has already went bad. Have no idea why it would though. I did however add a little bottle of STP fuel injector cleaner to the Jeep before getting gas on Friday. That is the only thing I can think may have caused the light to come on and possibly may have messed up the O2 sensor.

I will get the code reader out and check to see what it says the problem is and post back on here.


EDIT:

I did check later on yesterday and of course as I was thinking. The same exact code 52. Which means aparently the O2 sensor took a crap on me AGAIN. So, this makes me think that fuel injector cleaners must burn out some O2 sensors quickly. I also followed the directions on the fuel injector cleaner bottle, I know some are probably saying you added to much or not enough gas, this is not the case though. I guess I will try to get a replacement O2 sensor. Anyone know where I can buy a really cheap replacement?? I got my last one from an Ebay store I have been dealing with for a while, I could check to see if they would replace it(LOL, that was a joke).


One other thing, is there any way of adjuting the throttle on the Jeep? It is to sensitive when out trail riding. From idle to what feels like wide open and barely touching the throttle at all. Was thinking there has to be a way of adjusting this a little.

[msdz]

Some new problems. Yesterday I was driving and noticed the check engine light was no longer on. I did get lower grade gas than what I was using so thought maybe the fuel injector cleaner I used and higher grade gas made the light come on? Anywho... I stopped in at the store to get some cigarettes and got back int he Jeep and it did not want to run. I had to keep my foot on the gas pedal to keep it running but after I started moving and got home it idled fine.

One other problem I had was the jeep had some problems the other night with the security. I got it and went to start the jeep and the lights started blinking and it would not run. I had to use my key in the drivers side door and turn it left and right to get it to go off to get the Jeep to run again. Why did the security do this and any fixes for it?
While on the subject of security, I can only disarm the security system from the drivers side door and the rear hatch, not the passenger side door like it use to. What is the deal on that? I figured maybe a poor ground somewhere?
A lot of my issues I am having with my Jeep makes me wonder if the ground or something else is wrong with the wiring.

[MaryD]

2005 Jeep Grand Cherokee Laredo Full Time Transmission has sprang a leak!

Looks like it is dripping down on exhaust and of course it's hot some fluid on the bottom of the pan. On Tuesday it was fine, On Wednesday it had started loosing fluid. Filled with fluid, drove home without a problem and parked it. It has been sitting on a piece of plastic ever since the day before Thanksgiving 2012 and is now down to "A NO SHOW ON STICK" and the plastic is covered.

Never have had a problem with this jeep and would like to know if anyone else out there has had the same problem.

I did find an article that stated that it is probably the "Electrical Plug/Connector" a $9.00 part which I bought, but not sure just where to begin as far as working on it.

If anyone can help talk me through this issue I would appreciate it!

Thanks