Constant Stalling and shut off, sometimes able to restart... 1994 yukon 6.5 TD

[dragonriot]

6.5 Engine Diagnostic Troubleshooting Checklist

Copy and paste this checklist into a new post, then answer all the questions by typing in your data into the (red) blanks as indicated - click in the middle of the blank, start typing.


Problem: Explain your problem in concise language (ie: Cranks but won’t fire). _Began as an intermittent and sudden shut off, followed by immediate restart and no further problems. Now, when it dies, I'm lucky to be able to restart it and get myself home.___________________________

Demographics: tell us about your truck and your ambient conditions:

- Year: __1994____
- Truck model and class (ie: c2500) __Yukon (K5 Style)_______
- Automatic or Standard _Auto_________
- Mileage: (indicate miles or km) _220000________
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) __Chip, plugs, manual wastegate controller from HeathDiesel_________
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? __Turbo____________
- Ambient outside temp: (indicate *C or *F) __variable (wisconsin, lol) about 45 F now________
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) __#2 Diesel - up to 10% bio if I'm lucky_______
- What fuel additives are you using? __DieselPower Fuel Treatment on last tank_________
- Where are you located? __Milwaukee, WI___________

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter __1000 miles ago_______
- Fuel filter __1000 miles ago_______
- CDR Valve? _unknown________
- Coolant – last flushed/replaced at __last year___________
- Oil – synthetic/regular, changed at __Rotella T 15W40, Wicks, 1000 miles ago_________
- Batteries – state of charge, (matched set) replaced at _both new about 10k miles____________
- Battery cables and grounds (removed, cleaned and tightened): __new____________
- Glow Plugs - how many miles on them? __50,000_______ What type? __the good ones...___________
- Injectors - last changed at __unknown_____________


History: (Describe how the problem first appeared.)
- What were you doing when it happened? __daily driving____________
- How was the truck running fine before this problem appeared? __Truck always seems to run fine, right up to the stall___________
- Has this problem ever happened before? __hundreds of times over the past 4 months_____________________
- Describe any related factors that might be part of the problem. __PMD was relocated BACK to IP after service about 2 years ago... I was angry at the mechanic, and when asked why, they said that it doesn't matter. I have since tried to replace the FSDCooler I have for the IP mounted PMD, but the cable is too short.____________
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) _Yes___ And? _Code 23 and 39, cleared and driven for 10 miles... No reappearance of either code. Only getting Code 12 now._______


Diagnostics:

1] Starting:
1a] Does the engine start? __Yes_______
1b] Does the engine crank over? __Yes______
1c] Are your batteries fully charged? __Yes_______
1d] Have you removed, cleaned, and tightened all battery connections? __Yes______
1e] Does your Wait to Start light come on for a time? How long? __No, never_______
1f] Does your glow plug light come on? ___Yes______ For how long? _15-30 seconds depending on temperature________
1g] Do you see smoke from the exhaust while cranking? What color? __No, but on first start, a fair bit of white smoke is produced and goes away imediately______
1h] Does the Service Engine Light Glow during Start/bulb check? __Only while glowplugs are firing, but not during start______

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

3] PMD / IP Issues
3a] Location of PMD (on pump, on intake, remote mounted) __on pump - sadly_________
3b] Condition of Extension harness (if used) Vendor or Homemade? ___not used______
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. ___looks good to me______
3d] PMD Make: __Standyne_________
3e] PMD Age: ___Original I think - have replacement already mounted on FSDCooler__________

4] Stalling Issues
4a] Do you experience stalling only when hot? ___Yes, runs fine when engine first starts. I can drive about 10 miles before it starts to die repeatedly._________
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) _on accel_____
4c] Does pouring cool water over the IP seem to help with restarting? __unknown_______
4d] Is stalling momentary (engine recovers)? __usually, but as of late, it takes a much longer time to recover_______
4e] Does SES light come on when engine hiccups? __no, it shows no codes and no lights_______
4f] Does cruise control quit working when engine hiccups? __N/A_________
4g] Does re-starting seem to reset engine, restoring cruise and power? _________
4h] Changes to dash lights or instruments during stalling events? ___All gauges go to zero (except fuel)________

5] Running Issues
5a] On cold start, does upper rad hose get hard before engine warms up? __no_____
5b] Any bubbles or oil film in coolant overflow tank? _no______
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? _no_________
5d] Excessive white smoke from exhaust on cold start? __I wouldn't say excessive... but there is white smoke on every cold start_______
5e] Excessive black smoke from exhaust under hard acceleration? __Only slight black smoke________

6] Performance Issues
6a] Do you have gauges (boost, EGT) ? __no_________
6b] Maximum boost under load? ___set wastegate controller to recommended 1 3/4" length, unknown boost under load_________
6c] Have you added a performance PCM (reflash) or Chip? __yes, 80hp chip about 4 years ago from HeathDiesel___________
6d] Have you changed exhaust / downpipe / crossover? ___exhaust was new when I bought the truck, 3 1/2" all the way back_____________
6e] Wastegate – mechanical or vacuum (OEM)? __mechanical (aftermarket)____________

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

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.

__Neighbor has described the sound of my truck as marbles in a coffee can... I don't hear it, I just hear diesel rumble. Truck starts fine, and drives normally for about 5-10 miles, then starts to stall in traffic under acceleration. This is a semi-new problem, and have asked the only diesel performance shop in Milwaukee to check it out, they found nothing wrong... but they also forgot to reconnect the turbo oil hose after an air filter replacement, so I don't take much stock in anything they say now. I replaced the glow plugs, chip, and wastegate controller, and a previous mechanic moved the remote mounted PMD on FSDCooler back to the pump during service a few years ago. At least I have a spare... The cable seems to be stuck and too short to reach the FSDCooler mounted PMD, or I would have already put it back on the manifold. I would gladly remote mount the thing on the bumper... if I could afford more than fuel for the damn thing right now. heh. Truck has a Winter Package, which is handy because it gets mighty cold here in about a month. I haven't checked the fuel sock in the tank, as I haven't pulled the tank down in about 2 years. All filters are 1000 miles old and lift pump is newly replaced within the last year along with brand new fuel lines from the tank to the engine._______________________________

 

[NVW]

Sounds like PMD to me. Could also be LP or OPS, do you have fuel out of the water drain while engine is running?

 

[JMJNet]

x2, PMD or LP/OPS or all of the above.

 

[dragonriot]

Thanks for the suggestions guys... I replaced the PMD... it took me all of 5 minutes, and most of that time was spent looking for a wrench for the manifold bolts. The truck runs like a dream once again, starts clean and never dies... its got all the power it used to have and probably more.

 

[Burning oil]

Sounds like its fixed. Basicaly these trucks have a bad PMD or fuel delivery issues so they are easy to work on and cheap.
One thing I would do though if I was you is remote mount the PMD or put it back on the IP. PMD above the intake is the worst place for them.
My cable is only $30.

 

[dragonriot]

Took me a while to figure out where I posted this thread... I was looking for it on all the OTHER 6.5 forums, and by a stroke of luck, I logged in here tonight for something completely different and decided to search my threads. lol.

Leroy, I have the PMD mounted on an FSDCooler on the driver's side just above the original mounting position. It never gets hot where it is, though it is Winter in Wisconsin right now, so that could have something to do with it. If I have issues with it once the temperatures around here rise above 80 degrees, I'll probably remote mount it below the radiator or behind the driver's side battery... wherever I can fit it. heh.

Now I'm working on a new issue... I just replaced the driver's side battery to match the passenger's side battery because the previous one was almost 6 years old. The truck fired right up, and runs just fine, but my Charge gauge is telling me my alternator is barely charging above 10volts right now, and it usually runs right at 14 or slightly higher. I started out buying a new serpentine belt because I noticed the old one is a bit squeaky, but haven't had a chance to install it yet because it's been snowy here for the last couple days. I really don't want to replace the alternator AGAIN, as I already replaced it about a year and a half ago. Hopefully I still have the box and it has a 3 year warranty AND a receipt in it. haha.

Also, I was looking through the LMCTruck catalog for the door closer handles (on the inside door panels) and found that they aren't sold separately, AND that the door panels only come as a single unit, in pairs, and non-powered windows version. Do any of you have a source for inside door panels made for power windows, or replacement door closers separately?

 

[JMJNet]

The challenge with that PMD location is that it will get hot when the truck just been shut off and engine is hot after running.
The sorrounding temperature fluctuation/amplitude is what kills PMD.
PMD will generate heat when it is loaded/working.
When outside, PMD just have to deal with the outside ambient temp which is always lower than its working temp.
You may think it is fine now but when you move it outside later, it will experience a shock.
It is up to you, I don't sell PMD but people who does will like for you to put it inside the hood. LOL!!!

For the alternator, is the tach (RPM) goes erratic.
If yes, then the alt is bad.
If not, then there is cable issue somewhere.

When you replace batteries, need to do both at the same time.
May want to do load test on the batteries one at a time.

 

[NVW]

Make sure the battery post on the back of the alt is tight. If it can turn in the alt housing it will show a low charge.

 

[dragonriot]

Make sure the battery post on the back of the alt is tight. If it can turn in the alt housing it will show a low charge.

I thought of this and will check it tonight... I've also converted both batteries to top-post terminals, because I've previously stripped out every side post battery I've ever owned.

The challenge with that PMD location is that it will get hot when the truck just been shut off and engine is hot after running.
The sorrounding temperature fluctuation/amplitude is what kills PMD.
PMD will generate heat when it is loaded/working.
When outside, PMD just have to deal with the outside ambient temp which is always lower than its working temp.
You may think it is fine now but when you move it outside later, it will experience a shock.
It is up to you, I don't sell PMD but people who does will like for you to put it inside the hood. LOL!!!

For the alternator, is the tach (RPM) goes erratic.
If yes, then the alt is bad.
If not, then there is cable issue somewhere.

When you replace batteries, need to do both at the same time.
May want to do load test on the batteries one at a time.

Because of the cost of batteries, I have them tested independently, and replace the one that shows it is bad. The matching battery to the one I just bought was made in 2010, but still showed 1000CA and 800CCA when I tested it, while the older battery showed something like 600CCA, so that was the one I could afford to replace.

My truck, even in summer, never gets above 160 degree water temperature... by that I mean the temperature gauge is working, but never goes above the lowest marking on the gauge. I have replaced the thermostat, so I know it's not an issue being stuck open, even though that is more desirable than being stuck closed.. heh. I had the old PMD installed in the same location for 4 years before it was placed back on the IP by my mechanic one day... I still don't know why they did that, but if a $250 part lasts 4 years sitting on top of the engine, I'm ok with that. Money is the biggest issue for me right now, and when I have some to spare this summer, I will relocate the PMD. I still have to wait for some of the snow to melt here (8-12" on the ground at my house) before I can continue doing work on the truck, because my garage is taken up entirely by another car. As for the tach, it is steady. When I started the truck this morning, it fired right up. The Charge gauge went up to 14v, fired the glow plugs 3-4 more times in short bursts, and then settled back at 14v. As soon as I put the truck in reverse, the gauge started to drop. Within a mile of my house, it was just above the 11v line, and stayed there the remainder of my trip. I didn't have headlights on, and my heat was on low.

Speaking of heat... my heater blend door actuator is clunking for 30 seconds when I start the truck, and 30 seconds when I shut the truck off. I understand it is an easy fix, but there are 4 or 5 different parts available at the parts stores. I have the "C" heater controls if you look in the LMC catalog for 1994 Yukons/Burbs which is digital... Any idea which Heater Blend Door Actuator I should buy?