Diesel Place banner

1 - 17 of 17 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter #1 (Edited)
I have several issues with my truck: hard start cold, cruise kicks out, and check engine light (DTC36 and 88). After researching my problems I thought that my PMD would be the most likely cause because of the hard start and the cruise kicking out.

I got GMTDScan tech so that I could set the pump timing. I tried to do this and the DTC88 will not clear, nor can I set the TDC offset. The stepper motor seems to run correctly because the desired timing matches the measured timing. However the TDC offset is always 0*. So now I am thinking that I might have a problem with the PCM.

I have read alot on this forum and tried to find the answer to my problem with all the outstanding advice on this forum. But I haven't found the answer yet so here is my diagnostic checklist all filled out and hopefully someone will have some insight as to my problem.

1. Describe the problem you are having in detail:

hard start cold [engine temp] (extended GP time fixes), cruise kicks off, and check engine light. Throws DTC 36 (injector pulse width error response time too long) and DTC 88 (TDC Offset error) all the time.

2. Year of truck/engine.

1994 for both

3. Odometer reading (indicate miles or kilometers).

154200 miles

4. Indicate the model number on the Injection pump (starts DS4 or DB2......).

DS4 831-5521 manufacture date:2/27/2003

5. Indicate if you know if it’s a 1500, 2500, 2500HD, 3500, 3500HD.

K2500

6. Do you have an EGR on the engine?

No, vin F

7. Air Filter condition (visual check).

Clean

8. Fuel filter condition (freshly changed, mileage since changed).

unknown

9. Location of PMD/FSD? (ex. on pump/remote over intake, behind bumper).

Stock, on side of IP.

10. Outside Temperature (C or F). _____ °

60* F although outside temperature seems to have no effect on problems.

11. Service Engine Light while running?- on/off/intermittent

Yes, off when first started and driven then comes on after driving a short distance (1/4 mile)

11a. Service Engine light does glow during start/cranking/bulb check: Yes/No

Yes

12.Have you scanned for engine codes? Yes/No

Yes

12a. List exact results on engine codes.

DTC 36 Injector pulse width error (reponse time too long)

DTC 88 TDC offset error (will not clear)

13. Condition of Battery terminals (removed, cleaned and tightened).

Excellent

14. Known condition and age of Batteries.

Hold good charge, both 1 year old

14a. Are batteries a matched set of same age?

Yes

15. Condition of Major Grounds (removed, cleaned and tightened)

Excellent

16. Does engine crank, or "turn over"?

Yes

16a. Does engine start and run?

Yes

17. If engine does not start- Crack injector line: do you have fuel? Yes/No

N/A

18. Does your Wait To Start light come on?

Yes

18a.Number of seconds WTS light is lit.

15 seconds on PCM control

19. Engine Cranking speed (if you have an accurate tachometer).

unknown

20. Are you experiencing Stalling?

No

21. Check turbo inlet and air filter for obstructions.

Clear

22. In a no-hot start, pour a bottle of room-temp water on the injection pump. Does it start now?

N/A

23. Lift pump test - Describe results.

good flow, 8psi at idle.

24. Upon cold start, does the radiator hose get hard quickly? Yes/No

No

25. Upon cold start, do you have excessive white smoke? Yes/No

No

26. Do you have excessive cranking time before the engine starts? Yes/No

if not using the glow extender, yes

27. Have you used the block heater? Does it affect engine starting? (only try for starting problems).

Yes I have one, no it doesn't affect starting. (only used it once)

28. Are all glow plugs in proper working order?

Yes

29. During hard acceleration, do you have excessive black smoke? Yes/No

Yes

30. Do you have any unusual exhaust smoke issues?

unknown

31. Turbo check out - Pass/Fail

Pass, 7 PSI Max 2-3 PSI crusing

32. Indicate fuel that you are using: Bio-Diesel, #2 Diesel, SVO/WVO, other

#2 Diesel from local truck stop

33. Are you using any fuel additives? If so, please list.

No

34. Upon unscrewing fuel cap, do you have a large vacuum formed in the
tank? Yes/No

No

35. Do you have any service history available that might pertain to the problem you are having?

No

36. Please indicate any modifications to the vehicle that might help us diagnose better.

See signature, I also have GMTDscan tech
 

·
Registered
Joined
·
825 Posts
try disconnecting the batts for awhile to clear codes. You can't set timing (tdco) with codes present. You might have to rotate your IP to the pass side to get it to run without coding.
 

·
Registered
Joined
·
21 Posts
Discussion Starter #3
try disconnecting the batts for awhile to clear codes. You can't set timing (tdco) with codes present. You might have to rotate your IP to the pass side to get it to run without coding.
I've tried the battery disconnect and it still codes the 88 as soon as the key is turned on, without the engine running. Basically DTC88 is always present.

I will try retarding the pump and see if that stops it from coding. Thanks
 

·
Registered
1995 GMC Suburban
Joined
·
17,746 Posts
So did you put a !! NEW !!! PMD already.
 

·
Registered
Joined
·
21 Posts
Discussion Starter #6
So did you put a !! NEW !!! PMD already.
No not yet. I was waiting to get the GMTDScan and set the timing before I completely condemed the PMD. Of course I am unable to set the timing because of the code 88 that resets immediately after clearing. I'm going to try and retard the pump and see if it stops the coding as suggested in a previous reply.
 

·
Registered
1995 GMC Suburban
Joined
·
17,746 Posts
No not yet. I was waiting to get the GMTDScan and set the timing before I completely condemed the PMD. Of course I am unable to set the timing because of the code 88 that resets immediately after clearing. I'm going to try and retard the pump and see if it stops the coding as suggested in a previous reply.

But now you are condemning the ECM? In rare cases that may be true. IMO, you may have a bad PMD or the whole IP is bad. If it cannot crank, with bad PMD, obviously, you cannot set the timing since it needs to be up to temp.
 

·
Registered
Joined
·
21 Posts
Discussion Starter #9
But now you are condemning the ECM? In rare cases that may be true. IMO, you may have a bad PMD or the whole IP is bad. If it cannot crank, with bad PMD, obviously, you cannot set the timing since it needs to be up to temp.
the truck cranks, starts (with extended GP time), and runs OK. My thinking on the bad PCM is that the DTC88 cannot be cleared by any method; scanner, battery disconnect, PCM disconnect, etc. Therefore I was thinking that the PCM may be faulty. Again is only an thought and I wanted to run it by people here before I go throwing $300+ parts at a problem.
 

·
Registered
Joined
·
21 Posts
Discussion Starter #10
OK I retarded the pump timing about 2mm past the 0* mark on the engine and I still get the same thing: with key on and engine off I clear the codes and recheck codes immediately and DTC88 is present (historic and current)

I have tried to clear the codes using all the methods I can think of: 2 different scanners, battery disconnect, PCM disconnect, and the procedure outlined in the GM service manual (key off, jumper A&B, key on, apply brake and accelerator pedals until it flashes DTC12, release pedals, DTC12 flashes again, key off and remove jumper). The code DTC88 (historic and current) remain when rechecked.

Originally I thought PMD because of their historic failure rate and I have several problems that point to that; hard start, cruise kicks out, and mediocre performance. I decided to get the GMTDScan tech to get the timing set up correctly and see if that was the cause of any of my problems and continual setting of the same codes (DTC36, 88) before I bought a new PMD. Plus I figured I needed a good scan tool for this truck since the other one (Acutron 4140) I have only reads/clears codes and didn't display all the sensor outputs for this application nor could it perform any of the timing tests.

This whole thing is not a huge issue for me as the truck still runs and drives OK. But I do want it to be right and run the best that is can. My end goal is a truck that gets decent mileage (15-20mpg), is dependable and has decent power (I can pass when I need to).

So any help is greatly appreciated
 

·
Registered
Joined
·
7,380 Posts
Code won't change till you get to 170 degrees or better. ECM must see that.
Scannner temp? 170+ right ????
0 > Rotate pump toward drivers side > That's advancing not retarding.

Best to leave timing alone till you get all the other codes out!
 

·
Registered
Joined
·
21 Posts
Discussion Starter #12
Code won't change till you get to 170 degrees or better. ECM must see that.
Scannner temp? 170+ right ????
0 > Rotate pump toward drivers side > That's advancing not retarding.

Best to leave timing alone till you get all the other codes out!
Yes, engine is at operating temps according to the scanner (189.9*) and the DTC88 will not clear.

The only timing change I have tried is to retard it as suggest in another reply. I retarded it about 2mm past the TDC mark (toward the passenger side). Which resulted in no change other than the engine would not start, just cough and sputter with tons of white smoke. I set the timing back to where it was originally, about 4mm advanced. There is no other code set until the truck is actually driven and then it sets a DTC36 within about 1/4 mile.
 

·
Registered
Joined
·
7,380 Posts
DTC36 can be PMD. Suggest trying a good additive first and lot's of it.
Stanadyne Jr.

36 code is usually related to a pump problem but other factors can effect it.

May need a Tech II scanner to fix
 

·
Registered
Joined
·
3 Posts
I have the same problem but only with code 36. It usually comes on at 2000rpm but some times as low as 1500rpm but once the engine has warmed up completely it never happens again until the next day.
I have remote mounted another PMD and it still happens so I still have a backup PMD mounted on th IP. I put a #9 resister in and it does seem as it it takes a little longer to clear. This problem came with the truck 1994 Silverado. It has been like this for about 2 years now. The truck runs great and there is a noticable difference in performance.
Hope some one comes up with another idea. It allmost seems as if the fuel needs to be heated...

Reg
 

·
Registered
Joined
·
3 Posts
I have the same problem but only with code 36. It usually comes on at 2000rpm but some times as low as 1500rpm but once the engine has warmed up completely it never happens again until the next day.
I have remote mounted another PMD and it still happens so I still have a backup PMD mounted on th IP. I put a #9 resister in and it does seem as it it takes a little longer to clear. This problem came with the truck 1994 Silverado. It has been like this for about 2 years now.(I read an article somewhere that said this would get worse, but my problem has not.)The truck runs great and there is a noticable difference in performance with the #9 resistor.
Hope some one comes up with another idea. It allmost seems as if the fuel needs to be heated...
It is normal for the cruise control to kick off as they want you to notice the fact that the check engine light is on
Reg
 

·
Registered
Joined
·
21 Posts
Discussion Starter #16
DTC36 can be PMD. Suggest trying a good additive first and lot's of it.
Stanadyne Jr.

36 code is usually related to a pump problem but other factors can effect it.

May need a Tech II scanner to fix
Well I am on my second tank with additives. I am using Diesel Kleen in the gray bottle. I am put a quart in each tank, which is about double the recommended normal use. The instructions on the product also recommend this mixture at first.

It has made no noticable difference with the codes. They still come on at the same times and conditions. It has helped the cold start and quieted the engine noise some.
 

·
Registered
Joined
·
3 Posts
I have finally solved my DTC 36. I am based in Canada and have been using Mohawk Diesel (touted as environmentally friendly) I have switched to Shell diesel and no more rough starts or code 36. It did not matter how much additive I put in so for me I shall stay away from environmentally friendly fuels. At least I don't pollute on start up any more.
Hope this helps some one.
 
1 - 17 of 17 Posts
Top