97 blazer 4.3w timing


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iceman3032003
12-12-2011, 11:48 AM
Using a tech II scan tool it shows the timing is -11 but from what I can see is that the dist. has never been off. But also i do not know much history on the engine. Anyone have any thoughts on this when I bring number 1 up to compression it does look like it is off one tooth.

viggy58
12-13-2011, 06:58 PM
how many miles. is there any shaft play on the distributor?

is it having trouble running? throwing any codes?

iceman3032003
12-13-2011, 08:31 PM
it has 160,000 and i did pull the dist and the play is about average, it was not running good my son bought from a guy who said it just stopped running about a year ago after the guy tried a new fuel pump.
i have replaced all ecletronis emmisioon parts plus new rotor cap dist cap wires plugs coil ICM and also the cam sensor. we put new injectors on it and after that it would start but the idle was very fast almost 2000 rpm and still lots of black carbon from the tail pipe it also has a new cat. So i have thrown many parts at it with no improvement and yes the parts are ac delco or delphi from a dealer friend where I dod get them at his cost.
Now after re-installing the dist following the manuel procedure it will not even start now i am ready yo burn it. The only codes in the history are tps and ect both have been replaced

old_master
12-15-2011, 09:35 PM
Timing should never go into negative degrees. Should read very close to 21 degrees at idle. Hook up your techII and check camshaft retard. Bring RPM to 2,000 and back to idle. Should be zero degrees plus or minus 2 degrees. If the distributor is off one tooth, or more, P1345 will set.

iceman3032003
12-15-2011, 10:33 PM
Thanks Old master that is some good advice, I did not know the crank balancer had two marks i found the one that brings up the compression. Put the rotor to the 6 mark on the dist and it started right up but is missing like it is still off on the timing. ishould have given me the 1345 code but did not. it will idle ruff for about 5 mins then the idle gets very slow and ruff then dies. i have always had v- 8's i still love my 1993 full size blazer damn thise things are so easy to work on this 4.3 is busting my B###s but what can you expect when you buy a pig in a poke like this one who knows what all has been done to it before it was not maintained very well. i am still getting the ect and tps high voltage code and now a 560 code low voltage but i have not to drive it to cycle the codes out let me know what you think about the missing and ruff idle it is not showing any mis fire codes. the plugs are ac delco new but they are black and the wires are new ac delco with new dist cap and rotor also ac delco with a new cam sesor also.

old_master
12-16-2011, 02:59 PM
Yes, there are two marks on the damper. If you line them up like this, #1 is not necessarily on its compression stroke. What it does do, is put #1 cyl at TDC. It could be TDC of the compression stroke, or it could be TDC of the exhaust stroke, you still need to figure out which stroke #1 is on. Worst case scenario is rotate the crankshaft one revolution clockwise.

http://i561.photobucket.com/albums/ss58/cwhook/43LVortecFinding1TDC-Copy.jpg

Your "5 minute" time frame could be when the PCM goes into closed loop operation causing the difference in performance. Figure out and fix the timing issue first: We know there's a problem there and it might be the whole problem. If it still doesn't smooth out, check fuel pressure and leakdown.

iceman3032003
12-16-2011, 03:07 PM
yes getting ready to go work on it more today the fuel pump pressure is good new fuel pump and complete spider injecters also. if ican can keep it running long enought i am going to test each cyclinder the new spark plugs could be fouled since they are all so black with running so rich. Thanks again for you help

old_master
12-16-2011, 10:22 PM
Something else to check.... after the engine sets overnight, (at least 8 hours), before starting the engine, connect the techII & compare ECT & IAT temps, they should be within ~2 degrees of each other. Might want to make sure the cap is wired correctly too:

http://i561.photobucket.com/albums/ss58/cwhook/96newer43Lplugwires.jpg





Post your results.

iceman3032003
12-17-2011, 05:29 PM
I double checked the timing marks and that number 1 is up on compresion set in the dist. to the number 6 mark on the dist housing. made sure wires were correct per the firing order and the numbers on the dist. cap. the ect and iat were both -40 prior to starting the engine, when it starts it will not idle i need to rev it up to around 2000 rpm and it misses like the firing order is wrong I rechecked the wires and the timiming marks to the rotor button marks and the dist. marks all line up. This is my son in laws tech II I am not to knowledgeable about it but when it is running I looked at the mis fire graph and it shows no mis fire. One thing it is not doing now is the amount of black smoke from the tail pipe it is more white now. it is not showing the 1345 code but it is showing the 1100 codes for the tp and still also the code for the ect they will not clear. any more thoughts your help has been great so far thanks

rhandwor
12-17-2011, 05:54 PM
I double checked the timing marks and that number 1 is up on compresion set in the dist. to the number 6 mark on the dist housing. made sure wires were correct per the firing order and the numbers on the dist. cap. the ect and iat were both -40 prior to starting the engine, when it starts it will not idle i need to rev it up to around 2000 rpm and it misses like the firing order is wrong I rechecked the wires and the timiming marks to the rotor button marks and the dist. marks all line up. This is my son in laws tech II I am not to knowledgeable about it but when it is running I looked at the mis fire graph and it shows no mis fire. One thing it is not doing now is the amount of black smoke from the tail pipe it is more white now. it is not showing the 1345 code but it is showing the 1100 codes for the tp and still also the code for the ect they will not clear. any more thoughts your help has been great so far thanks
Did you double check the wiring for the injectors when you worked on them?

old_master
12-17-2011, 05:59 PM
If ECT and IAT were both showing -40, there's a problem. I don't think the temperature in Ohio got quite that cold last night ;)

-40 is a default reading.
Check fuse #9, 20 amp fuse, should show battery voltage at all times.
Check fuses #4, #5, #10, #12, & #15 all should show battery voltage with the ignition in RUN and START positions.

Check both terminals of each fuse with a voltmeter or test light & post your results

iceman3032003
12-17-2011, 06:33 PM
I will check the temps again on the ect and iat to be dure they are right with what i said. # 9 was 12.54 4 -11.44 5 - 11.49 10 - 10.54 12 - 11.44 i could not get a reading from #15

old_master
12-17-2011, 08:45 PM
Fuse #15: You can check the pink wire at the mass air flow sensor with the ignition in the RUN position. Let us know what you find on the recheck of ECT and IAT.

iceman3032003
12-17-2011, 10:15 PM
I re-checked #15 and it was reading 8.97 the battery was reading low also so i put a charge on it for the night. I looked at the ECT it is now showing 86 at start up but the IAT is still showing -40

iceman3032003
12-17-2011, 10:51 PM
Something i am not sure if I said before but i am also getting a code 560 system voltage but i cannot find any reference to it any place

Tech II
12-17-2011, 11:01 PM
Isn't this distributor non adjustable? Only goes in one way?

iceman3032003
12-17-2011, 11:32 PM
yes thats is right the dist cannot move once in place not like others on older motors.

Tech II
12-18-2011, 08:13 AM
So if it only goes in one way, then you just have to look at the cam retard data.....as previously reported, it should be 0 degrees +/- 2 degrees....

old_master
12-18-2011, 08:30 AM
I re-checked #15 and it was reading 8.97 the battery was reading low also so i put a charge on it for the night. I looked at the ECT it is now showing 86 at start up but the IAT is still showing -40

#15 will read battery voltage at the ECT. If battery voltage was low, charging the battery should bring that up and it's probably ok.

The 86 degree reading on the ECT: If the engine was partially warmed up, that reading is probably ok. The -40 reading on the IAT is a problem. It should read very close to ambient temperature. Unplug the IAT connector and check resistance on the black wire to ground, should be less than 5 ohms. Turn the ignition to RUN and check voltage on the tan wire and post your results.

iceman3032003
12-18-2011, 10:25 AM
I will run those tests on the wires at the IAt and then post them, and thank you also Tech II the cmp retard was showing -11 before i reset the dist and now it is showing 0 and when the engine is running at about 2000 rpm it was showing -5 to -7 as the engine was reved up but i could not let it idle it will die.
One thing i also noticed when it was running the tps was showing ok but the angle never moved it showed 0 angle even when i would give it more throttle just some info there that might help I wish I knew more about this Tech II scanner it does look like it can give alot of info.

iceman3032003
12-18-2011, 02:45 PM
well for what ever reason it has smoothed out it will start by just turning the key. It will idle around 2200rpm for about 2 or 3 mins then begin to idle rough and if you try to get the rpm back up it will back fire if you then just do not try to rev it up it will shake and die
one other thing I have noticed on the scanner is the tps is showing a code for high 123 and 1121 high voltage reading the manuel it says that the voltage should be 0.36-0.96 at idle and as high as 5.0 wide open the scanner shows it as 4.98 all the time the same with the ect
WOw buying a car for 500 is a pig in a poke when it is not running like this one.

old_master
12-18-2011, 03:17 PM
TPS voltage at 4.98 is telling the PCM the throttle is wide open all the time. Check the TPS wiring for a short between the VREF and the TPS signal wires at the sensor connector. If no short, replace the TPS sensor. You might find that if you disconnect the TPS, it might idle fairly decent.

Camshaft retard: Engine RPM must be brought up so the PCM can accurately determine what camshaft retard actually is. After that it should remain constant. Run the idle up to at least 2,000 RPM for a second or two. When it returns to idle, it should be zero degrees plus or minus 2 degrees. To adjust it, rotate the distributor. If you can't get it within specs, the hold down must be modified.

Tech II
12-18-2011, 04:55 PM
So, with key on engine off, tps reads 4.98?

Disconnect tps....what does it read?

ECT is still reading -40F along with IAT?

old_master
12-18-2011, 05:04 PM
With everything connected as it should be, key on, engine off:
TPS should read ~.5 VDC.
ECT should show actual coolant temperature.
IAT should read very close to ambient temperature.

With the engine stone cold, (after setting approximately 8 to 10 hours without starting it) the ECT, IAT and ambient temperature should all read within 2 degrees of each other.

EDIT: if you have problems with three different circuits, there is probably a short circuit somewhere.

iceman3032003
12-18-2011, 05:05 PM
when i put a digital volt meter into the hot of both tps and ect it reads over 5.0 for both i am getting a ground at both with a test light from ground to the power wire. the tps and ect are both new

old_master
12-18-2011, 05:10 PM
When testing PCM circuits, don't use a test light, use a DVOM only.

When checking ground at the ECT, TPS and IAT, turn the ignition off, and unplug the sensors. Then check resistance from the black wire in each sensor connector to battery negative. Each one should read less than 5 ohms. Post your results.

iceman3032003
12-18-2011, 05:16 PM
yes i am looking for the sensor ground connector to see if it is dirty or lose just to start there.

old_master
12-18-2011, 05:24 PM
They all don't necessarily ground at the same place.

iceman3032003
12-18-2011, 05:28 PM
The ECT, TPS, and MAP all show 4.98 or 5.2 with the key on all show less than .5 ohms with key off to battery neg.
Also something I just now see on the tech II reading for ignition 1 is 25.5 volts and the the engine data 1 says it should read 13.5 volts that is from the shop manuel for the scan tool display for a 4.3 looks like I may have some voltage problems but where

old_master
12-18-2011, 05:33 PM
You've got a bad ground somewhere. Take the negative battery cable off of the battery, clean and shine it up, then tighten it up. Then follow the smaller black wire at the negative battery terminal to where it connects to ground. Take it apart, clean and shine it up and tighten it up. Post your results.

maxwedge
12-18-2011, 05:52 PM
Maybe he is checking reference voltage of 5.0 at these connectors?

iceman3032003
12-18-2011, 07:04 PM
I am getting codes 123 tp high voltage,1115 ect intermittent high voltage, 1121 tp sensor intermittant high voltage. The tech II scanner shows both at 4.98 with key on motor not running.both should be less than .80 at idle they also show 4.98 with key on using a digatal volt meter they show over 5.0 the tech II is also showing that ignition 1 is 25.5 volts needs to be 13.5 on engine data 1.
I cleaned all the grounds for the battery no change in the readings and it now even will not idle fast like before you must keep it reved up but still after about 2 mins it starts to backfire shake and die.

old_master
12-18-2011, 07:44 PM
On the passenger side inner fender, mounted on top of the coolant reservoir, is the VCM. There are 5 connectors. With the ignition off, disconnect the connector marked "C" and being very careful not to damage the pins:

Check resistance from pin #17 (tan with white stripe wire) in the connector to battery negative. Must be 5 ohms or less.

Also check the grounds on the rear of each cylinder head, (close to the firewall).

Post your results.

EDIT: correction of connector & wire color.

iceman3032003
12-18-2011, 08:25 PM
This VCM has 5 connectors, one smaller one in the middle of the top two. Yes that was my next thing is the grounds, both the tp and the ect are both on the same ground according to the manuel. They go to a ground block which I need to find yet, thanks aginn for your help.

old_master
12-18-2011, 08:29 PM
The ECT, TPS and IAT all ground internally in the VCM. See post #33.

rhandwor
12-19-2011, 10:49 AM
Look for a black or Blk Wht ground left front of cylinder head.

iceman3032003
12-19-2011, 12:05 PM
Yes i am tracking all ground wires to clean them so far all look ok but cleaning them is good.

iceman3032003
12-19-2011, 02:16 PM
I have clean all grounds and also checked the pin 17 for its resistence it is ok. These sensors are showing 4.98 on the scanner, IAT, MAP, ECT, TPS, and the Fuel level sensor.
These are the codes I am getting;
P0118 ect swensor high voltage
P1115 ect sensor CKT intermittent high voltage
P0123 tp senor high voltage
P1121 tp sensor CKT intermittent high voltage
P0463 fuel level sensor circuit high voltage
P0560 system voltage I cannot find any reference to this one
P1621 long term memory
I am going to clean all grounds again to be sure I did not miss one, the code P0560 seems to maybe be the key here.
I say this again thanks to all who have helped so much and Old master for sharing his vast knowledge, but I am not ready to give up on this thing.

old_master
12-19-2011, 03:24 PM
Were you able to locate and clean the grounds on the rear of each cylinder head? Make sure there are no broken wires near them just dangling around.

iceman3032003
12-19-2011, 03:50 PM
Yes I took loose from both block and frame cleaned ans sanded all parts all wires seemed in tact no loose wires. Started the engine no change and no change in the tech II info.

old_master
12-19-2011, 06:48 PM
If resistance on the tan wire, (pin 17) to ground was 5 ohms or less, we at least know the PCM is getting ground.... whether its getting where it needs to go inside the PCM is another story ;)

P1115 & P1121 indicate intermittent high voltage to the sensors: I have seen cases where an alternator can create voltage spikes and cause all kinds of crazy stuff: In post #32 you said ignition 1 was 25.5 volts: Just for grins & giggles, disconnect the brown wire and the red wire from the alternator. Connect the scan tool. Check voltage on Ignition 1 and see what it reads with the engine off & when it's running.

rhandwor
12-19-2011, 06:50 PM
http://www.labscopes.com/pg09.htm
This is not common but bad diodes in the alternator can cause A-C voltages which will cause numerous problems. The web site tells how to check for this with a DVOM

old_master
12-19-2011, 07:41 PM
yea, what he said ;) More detail than I used, but that's exactly it. Working in the dealer on a brand new 1980 Pinto, about pulled my hair out trying to figure out. Warranteed the part and the factory called it back for inspection claiming it wasn't possible.

iceman3032003
12-19-2011, 07:54 PM
I can't keep it running long enough to check anything while it is running, I am going to take the alternator to a napa shop tomorrow to get it tested just to clear that off my mind.

old_master
12-19-2011, 07:58 PM
Hold on.... those testers aren't worth the powder to blow 'em up!

If you can't get it running long enough, it's probably not the alternator. Just disconnect it and check Ignition 1 voltage on the scan tool.

EDIT: In post #38 you listed the DTC's that are in memory. Is that the exact order they were retrieved?

maxwedge
12-19-2011, 08:35 PM
How do all the sensors show maximum 5v reference voltage, engine not running, are looking looking at the pcm inputs from the sensors? I believe those codes refer to intermittent high voltage "FROM THE SENSORS", no?

old_master
12-19-2011, 08:41 PM
Yes Shep, he's showing VREF on the TechII from the sensors. IAT & ECT are indicating -40F and TPS is indicating WOT.

EDIT: The P1621 is a DTC for a faulty VCM, but I'm not so sure it is. I'm trying to determine if the VCM is missing ground somewhere, or something screwy like that. Feel free to jump on in, I know you've got a ton of experience on this stuff too ;)

iceman3032003
12-19-2011, 08:57 PM
They are listed in the scanner from low to high codes, I am sorry I did not put the whole info for that 1621 it says control module long term memory performance.
if I dis-connect the red wire from the alternator then all power is off to the system. It has a small brown at just one clip and then the large red one and then with it is a green and black wire together.

iceman3032003
12-19-2011, 09:00 PM
How can I find out if this vcm is the right one for this engine like I said I have no knowledge of this cars history is that a posibility ?


I can see where the clips have marks on them like they have been taken off using a screw driver.

old_master
12-19-2011, 09:05 PM
Have you seen this thing actually run? Or did you aquire it as a basket case?

According to my 1997 schematic, there are only two wires to the alternator, brown and red.

iceman3032003
12-19-2011, 09:15 PM
My son bought it from a buddy of his last march or so, they guy told him it was running fine and just stopped one day. The guy bought a airtex fuel pump from autozone and put it in and it still did not run. He was pissed and my son bought it for 500.00 dollars it has a great body, he thought he could make some money on it. Well he gave up and now I am trying to get it running, throwing parts at it and was that wrong.
The clip on the side of the alternator has one light brown wire to it, on the back is a post and the big red wire, and then two wires together under the red wire they are black and the other is dark green.

old_master
12-19-2011, 09:21 PM
The brown wire has a connector that plugs onto the regulator terminal on the back of the alternator, sounds like that one is fine. The red wire has an eyelet terminal and is held onto a stud with a nut and might have a rubber boot over it. It should have battery voltage, check it. Remove the nut, remove the black and the green wires and just put the red wire on and tighten it up..... see what happens.

iceman3032003
12-19-2011, 09:33 PM
Black wire goes to the starter I tried it but all the electical was of just like if the battery was di connected. Hooked it back up and still all the same.

old_master
12-19-2011, 09:41 PM
On the starter: There should be a larger, (4 gage) probably black, cable that goes directly to the battery positive terminal. There should also be a 10 gage purple wire going to the small terminal on the solenoid, (mounted to the top of the starter). Those are the only wires that should be at the starter, remove anything else.

old_master
12-19-2011, 09:57 PM
Black wire goes to the starter I tried it but all the electical was of just like if the battery was di connected. Hooked it back up and still all the same.


My guess on this is the red wire does not have voltage all the time, and it should. The original red wire has a fuse link in it and it probably blew out when "they" shorted something out. This wire is what charges the battery, that's all, it should not shut everything off as you stated which means there is somewhere else that "they" have been fooling with. Trace the red wire back until you find the fuse link. Tell me what you find there.

iceman3032003
12-19-2011, 09:57 PM
The green and black are together in the same type of eyelet as the red and they do look factory. I am looking to see where they go to the back of the engine over the passenger side rocker arm cover. The green is heavier gauge than the black both are about the same gauge as the red wire. And yes I was wrong about thenm going to the starter.

old_master
12-19-2011, 10:01 PM
Ah ha, I'm thinkin' this is our "lost ground". I'll search the schematic and see what I can find, but those two wires probably go back into the harness up toward the front of the engine. Does the red wire on the alternator have battery voltage all the time?


Edit: If the black and green are attached together in the same eyelet, they are grounds and most likely attach to the bolt in the rear of the passenger side cylinder head. Multiple grounds for the engine controls. This would explain the high voltage readings you're getting. Look closely on the eyelet for "witness marks" from a star washer. If so, guaranteed it's a ground.

iceman3032003
12-19-2011, 10:06 PM
Yes the red wire has battery voltage it is connected to the battery with a fusable link. Both these wires go to the back of the mottor into and wiring harness. But they are factory connected together in the eyelet.

old_master
12-19-2011, 10:14 PM
Check resistance from the eyelet to battery negative and post what you find.

iceman3032003
12-19-2011, 10:33 PM
I did not get any resistance from them with out them connected to the same post as the red wire. With them connected to that post I get 12.58 volts from the battery.

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