Hopefully someone will know???????

[adavis12]

I have a 97 chevy 2500 6.5 td. It is so far, on it's second mechanic.Here is the problem from the begining:

1 - I was driving along and it started bucking and quit on me. I changed the fuel injector pump (that also came with a new PMD).

2- It would run till it warmed up and then would shut down. You could turn the key off and turn it back on again and it would star up but you would have to keep it at 2000 rpms for it to run smooth.

3 - The last mechanic, a very knowledgeable guy with the 6.5, has tried everything under the sun and it is still doing the same thing.


Any one have any ideas?

 

[vail426]

http://www.dieseltowingresource.com/showthread.php?t=6300

 

[mfgguru]

Sucking air or lack of fuel ie. Lift pump or plugged tank sock. Simple things to check out. Start with the easy stuff and work your way to the more complex.
Fill out the diagnostic checklist for a more thorough explaination of your problem.
Somebody will have the anwser for you.

 

[Rodd]

I concure w/ the 2 previous posts you need to fill out the checklist. Vail linked to it. If your mechanic is a knowledgable 6.5 tech then it should be working for you now. I am afraid he may have replaced the IP prematurely. When replacing the IP he should have dropped the tank and cleaned it out (there is a lot of junk in there that can work its way through the fuel system), he also should have replaced the Lift Pump and fuel filter as well as cleaned the fuel filter manager. If this wasn't done then the contaminates in the fuel system can cause a premature death to the new IP.

Checklist, checklist, checklist...... The only way to find out what the problem is.

 

[adavis12]

Checklist

I will fill out the checklist in the morning from work.

When hooked up to the Scanner, running at an idle, the computer is telling my injection system to run as if it were under a load when it is running at an idle in reality. The filter and lift pump are brand new. I read over the check list and from reading on here everything is pointing to PMD, which is also new, or the computer (Located behind my glove box). He has a good PMD he is going to hook up tomorrow to see if that is the problem. If not he is pointing towards the computer. What he is also questioning is that the computer should be sinced to the resistor board ( Usually done through TDC Offset process ). Since the computer won't let him do this process he is thinking it might be the computer. The truck will shut off once the motor reaches 170 degrees. Once it shuts down it will start up again if you press the accellarator a little bit. It will run normal at 2000 rpm's however white or grey smoke billows out of the tail pipe at this time. I inquired at my local napa about the Computer and it is 165.00 plus the cost to flash the computer. Has anyone ran into this problem before? or does any of this sound familiar? I am also thinking, from reading on here, that relocating the PMD is a good thing to do.

 

[NVW]

Clean all the grounds, batt and chassis etc, then clean your fuses, shine the fuse spades up with emery cloth. The fuel shut off sol fuse can cause the truck to quit if there is bad contact. Leo

 

[JiFaire]

The truck shuts off once it hits 170*? That rings a bell.

You need to do that checklist. I'd also like to know if you (or your mech) changed the resistor value when changing the PMD. I'm also curious about whether the thing has been re-timed (new TDLearn procedure).

 

[buddy]

Did you get specifics on the idle IP timing, fuel rate, and TDC Offset? No codes? The problem seems to be you have a mechanic that needs to do electronic diagnostics, which many people dont seem to like to do. Have to read voltage values and compare to expected and interpret results. Otherwise will be doing part swapping a lot.

 

[adavis12]

- Year: 97
- Truck model and class (ie: c2500) K2500
- Automatic or Standard - Auto
- Mileage: (indicate miles or km) -170000
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) IP, PMD, Crank Sensor.
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? - Turbo
- Ambient outside temp: (indicate *C or *F) ?
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) ? Were i live it doesn't say #1 ect. Just 40 as what i would assume is the octane
- What fuel additives are you using? Diesel cleen
- Where are you located? NY

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter 160,000
- Fuel filter - brand new
- CDR Valve? ?
- Coolant – last flushed/replaced at Brand New
- Oil – synthetic/regular, changed at 169,000 - Rotella 15/40
- Batteries – state of charge, (matched set) replaced at-Brand new
- Battery cables and grounds (removed, cleaned and tightened): NO
- Glow Plugs - how many miles on them? 170,000What type? OEM
- Injectors - last changed at Not to my knowledge


History: (Describe how the problem first appeared.)
- What were you doing when it happened? DRIVING
- How was the truck running fine before this problem appeared? NORMAL

- Has this problem ever happened before? no
- Describe any related factors that might be part of the problem. IPO was bad. When i changed it i checked it to make sure it was bad. WHen you manually turned it, the pump felt like there was a bad bearing. I don't know if there are any bearings, but that is what it felt like. My mechanic thinks a shaft inside the old pump broke.
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) ____ And? Nothing is coming up except timing issue. The ecm will not let my mechanic set it.


Diagnostics:

1] Starting:
1a] Does the engine start? __y
1b] Does the engine crank over? _y
1c] Are your batteries fully charged? _y
1d] Have you removed, cleaned, and tightened all battery connections? _y
1e] Does your Wait to Start light come on for a time? How long? _10 seconds
1f] Does your glow plug light come on? __NA For how long? _________
1g] Do you see smoke from the exhaust while cranking? What color? __n

2] Fuel Issues (if not running):
2a] Can you hear your lift pump working? __y
2b] Do you get a steady flow of fuel from the water drain (T-handle) ? __y
2c] Loosen the inlet line from the IP – is fuel coming out (Lift Pump on)? __?
2d] Loosen an injector line and crank the engine - does fuel come out? _Y
2e] Do you hear a vacuum (hiss) when you remove the fuel cap? __n

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted) __on pump
3b] Condition of Extension harness (if used) Vendor or Homemade? _________
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. __good
3d] PMD Make: __standyne
3e] PMD Age: ___new

4] Stalling Issues
4a] Do you experience stalling only when hot? __y
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) _170 degrees
4c] Does pouring cool water over the IP seem to help with restarting? _havent tried that
4d] Is stalling momentary (engine recovers)? __n
4e] Does SES light come on when engine hiccups? __n
4f] Does cruise control quit working when engine hiccups? _?
4g] Does re-starting seem to reset engine, restoring cruise and power? _n
4h] Changes to dash lights or instruments during stalling events? _y

5] Running Issues
5a] On cold start, does upper rad hose get hard before engine warms up? __don't know
5b] Any bubbles or oil film in coolant overflow tank? _n
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? __n
5d] Excessive white smoke from exhaust on cold start? __n
5e] Excessive black smoke from exhaust under hard acceleration? __n

6] Performance Issues
6a] Do you have gauges? __y
6b] Maximum boost under load? __don't know
6c] Have you added a performance PCM (reflash) or Chip? _n
6d] Have you changed exhaust / downpipe / crossover? ___n
6e] Wastegate – mechanical or vacuum? __Vaccum

7] Temperature-related Issues:
7a] Single or dual thermostats? __dual
7b] Have you replaced them lately? Manufacturer of replacements? new
7c] Have you pulled and cleaned Radiator and coolers lately? _n
7d] Have you replaced the fan clutch? Manufacturer of replacement? _n
7e] (winter) Have you tested your antifreeze? Good to what temp? new
7f] (winter) Are you using a winter grille cover? _n

List and describe any other factors which are not addressed in this checklist. We can’t see, hear, smell, or touch your truck, so the more descriptive information you can give, the more likely it is that somebody can assist you.


Once the truck warms up to 170 degrees the engine shuts off. My mechanic told me the computer is telling the truck that it is under a load and it is flooding out. the computer will not allow my mechanic to change the timeing with a scan tool.

 

[adavis12]

What do you mean changed the resistor value?

The truck shuts off once it hits 170*? That rings a bell.

You need to do that checklist. I'd also like to know if you (or your mech) changed the resistor value when changing the PMD. I'm also curious about whether the thing has been re-timed (new TDLearn procedure).

 

[mfgguru]

There is a resistor that sits in the plug of the PMD/FSD. You can get resistors with different values, #5 being the stock value, #9 being the so called "high perf" value.

 

[adavis12]

Update

Well here is the point i am at. A gm tech 2 scanner was used to see if we could do the TDC process for my fuel injector pump. it did not work. fo rsome reason my truck will not let the pump phase to the motor. We also put in a new computer. Anyone have any ideas?

 

[bison]

I do not think a scanner can set the timing or TDC offset,but just check the settings.
Your mec should do the KOKO procedure.

Clear all codes.
Key On,engine off,trottle to the floor for a minimum of 1 min.
Key Off,release trottle,for a minimum of 1 min.
Start engine ,let it warm up to 170 degree minimum,
The computer will overwrite the TDC offset to new value the moment the temp is reached
Check with the scanner if TDC is within specs 0.25 to 0.75, if not, then the IP has to be manually retarded or advanced by turning it[need to loosen the mounting bolts for that]

IF KOKO dont set , try it again with increasing both the 1 min times to 2 min minimum.

 

[buddy]

Does the tech 2 connect to the PCM and show you the current values? Or can you not even connect? Does the SES light work with the IGN ON, engine OFF?

It may not allow it to set TDCO if the actual TDCO is out of tolerance, so greater than +/- 2.02. Youll actually have to turn the IP to retard or advance it and run the procedure.

My GMTDScan can run the procedure itself, and so can the Tech2 according to the GM manual. But the mechanic has to be smarter than the truck.

What codes did you actually get?

 

[bk95td]

If the engine isn't up to 180 or there are any codes present or historical the time set and tdcoffset learn won't work. Pump timing could be too far out of range. How can this mechanic see that there is a load present with a scan tool? Thats a new one to me.
Also I would think about new/rebuilt injectors and glow plugs with that many miles on them.

 

[Goldsburg]

If the engine isn't up to 180 or there are any codes present or historical the time set and tdcoffset learn won't work. Pump timing could be too far out of range. How can this mechanic see that there is a load present with a scan tool? Thats a new one to me.
Also I would think about new/rebuilt injectors and glow plugs with that many miles on them.

Simple: He can look at the "% engine load" or also the commanded fuel rate (at idle).

Regards,

 

[NVW]

x2, Carcode shows % engine load as well as fuel rate.

Leo

 

[buddy]

Its still better to have the person actually tell you what he is seeing, what values. If the guy was smart enough to fix it then Id say let it be, but sounds like youve not received a real great diagnosis here, so start asking what he actually gets for these values, and we can tell you whats wrong.

At least clear the code before trying to set TDCO.

 

[Turbine Doc]

Is your mechanic using a real GM tech 2 with TDC learn command function or a clone that is capable of reading OBD-II codes and TDC value without commanding the learn.

A GM T2 can read and set TDC off set, so long as there is sufficent window, once engine is fully warmed up >180F water temp, all codes cleared (any stored codes and learn can't take place), controlled rev engine slightly with throttle & watch TDC change, then hit learn and it should capture the highest TDC in the window, if window is too small you'll have to loosen the IP and rotate 1 mm toward driver side to advance it, or to pass side to retard, lock down top IP nut, then rev/learn command until you get the desired TDC offset. Go too far with it -2.02 or +2.02 and you'll code and have to back up a little toward appropriate direction to advance/retard away from the (+/-) 2.02 max setting.

If you don't have a real GM or direct copy of GM-T2 then you will need to use ko/ko & App to floor learning method.

 

[JiFaire]

No, we're getting too far from the oiginal issue here, guys. Basics... everything is basics.

We know:

1] The truck runs fine until it hits 170*.
2] That is the minimum temp that an OBD-II system will use to try and change system settings.
3] The OBD-II systems will try to re-learn resistor values or timing on start if warm enough.

Possibilities:

1] New resistor in new PMD is different than the stored value in PCM.
-- cure: either change resistor back or re-sync PCM to IP (ko-ko as bison suggests)
2] timing out of range... when temp hits 170*, IP loses cold advance and starts running crappy
-- cure: re-set timing
-- catch: can't do that if a code is present, which could be related to [1] above

Keep things simple... the truth is out there.