97 suburban 6.5 diesel

[2fastforyou]

Hi, Im new here! I have a 1997 GMC suburban with a 6.5 Diesel that I tow my dirt race car around with. I bought the thing about 8 months ago and have had nothing but problems with it and hopfully I can get some help here. I went out 2 days ago in the morning to start my truck and the lights all came on as always but motor just cranked over...I ended up killing the batt. so I tryed jumping it and still would not start..pulled out the fuel fiter and noticed it was dirty..went to work and on my way home i stoped and got a fuel fiter put it in and i fired right up after bleeding the system, drive it about 10 miles and parked it for the night thinking it is fixed. Went back out the next morning and same thing...no start... got home from work and after habving the batt. charger on all day the truck fired up ran for a few mins and shut off, started it right back up and it ran and shut off again. Got it started again after taking the fuel pump apart and cleaning it. Fired right up, 15 mins later it would not fire so I bleed the system again and all kinds of air came out. 3 weeks ago I put in a new fuel tank so I dropped the tank to check the lines and noticed that the fuel line was bad so I cut the bad spot out and replaced with rubber hose, put the tank back in and still nothing. crank crank crank thats it..I bleed the fuel filter and fuel comes out so I know the pump is working. I have a big race coming up this sat. and need to do somthing fast..lol..im dieing here! HELP I will even except a phone call to resolve this problem, im not much of a typer at 330-383-5035 Thanks

 

[Matt Bachand]

IF your rubber patch work is leaking you'll be sucking air bubbles into the fuel system causing all sorts of problems.

 

[Slim Shady]

Hi, Im new here! I have a 1997 GMC suburban with a 6.5 Diesel that I tow my dirt race car around with. I bought the thing about 8 months ago and have had nothing but problems with it and hopfully I can get some help here. I went out 2 days ago in the morning to start my truck and the lights all came on as always but motor just cranked over...I ended up killing the batt. so I tryed jumping it and still would not start..pulled out the fuel fiter and noticed it was dirty..went to work and on my way home i stoped and got a fuel fiter put it in and i fired right up after bleeding the system, drive it about 10 miles and parked it for the night thinking it is fixed. Went back out the next morning and same thing...no start... got home from work and after habving the batt. charger on all day the truck fired up ran for a few mins and shut off, started it right back up and it ran and shut off again. Got it started again after taking the fuel pump apart and cleaning it. Fired right up, 15 mins later it would not fire so I bleed the system again and all kinds of air came out. 3 weeks ago I put in a new fuel tank so I dropped the tank to check the lines and noticed that the fuel line was bad so I cut the bad spot out and replaced with rubber hose, put the tank back in and still nothing. crank crank crank thats it..I bleed the fuel filter and fuel comes out so I know the pump is working. I have a big race coming up this sat. and need to do somthing fast..lol..im dieing here! HELP I will even except a phone call to resolve this problem, im not much of a typer at 330-383-5035 Thanks

First welcome to DTR this is the place to get expert help, I mean expert not amateur guesses. OK there is a form to fill out in the sticky section (top of the page). This diagnostic form will help us determine what you have and what is normal and not normal.

I would check the Oil Pressure Switch, OPS sounds like it may be intermittent. This is a big problem on the trucks along with the PMD, This is speculation though at this point.

Here is a copy that you can fill out


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

- Year: _____
- Truck model and class (ie: c2500) _________
- Automatic or Standard auto__________
- Mileage: (indicate miles or km) _________
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) _
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? ______________
- Ambient outside temp: (indicate *C or *F) __________
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) __1 or 2_______
- What fuel additives are you using? ___________
- Where are you located? _____________

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter _________
- Fuel filter _________
- CDR Valve? _________
- Coolant – last flushed/replaced at _____________
- Oil – synthetic/regular, changed at _regular __________
- Batteries – state of charge, (matched set) replaced at _____________
- Battery cables and grounds (removed, cleaned and tightened): ______________
- Glow Plugs - how many miles on them? _________ What type? _____________
- Injectors - last changed at _______________


History: (Describe how the problem first appeared.)
- What were you doing when it happened? ______________
- How was the truck running fine before this problem appeared? _____________
- Has this problem ever happened before? ______________________
- Describe any related factors that might be part of the problem. ______________
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) ____ And? ________


Diagnostics:

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

2] Fuel Issues (if not running):
2a] Can you hear your lift pump working? ____________
2b] Do you get a steady flow of fuel from the water drain (T-handle) ? _________
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? _________
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) ___________
3b] Condition of Extension harness (if used) Vendor or Homemade? _________
3c] Condition of grounds / ground wires to IP / PMD. Check Harness. _________
3d] PMD Make: __________
3e] PMD Age: _____________

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

5] Running Issues
5a] On cold start, does upper rad hose get hard before engine warms up? _______
5b] Any bubbles or oil film in coolant overflow tank? ______
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? __________
5d] Excessive white smoke from exhaust on cold start? _________
5e] Excessive black smoke from exhaust under hard acceleration? __________

6] Performance Issues
6a] Do you have gauges? ___________
6b] Maximum boost under load? ____________
6c] Have you added a performance PCM (reflash) or Chip? ______________
6d] Have you changed exhaust / downpipe / crossover? _
6e] Wastegate – mechanical or vacuum? ______________

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.

 

[JiFaire]

Hi there, 2fast... welcome to the DTR! By fluke, accident, or design, you have stumbled upon the best 6.5TD site on the 'net.

Take a minute to fill out your signature (click the signature link in mine) so we all see what your truck is made of. We're going to want you to do some diagnostics and get you to fill out a checklist pretty soon, but let's see if we can't get some simple data first:

Q: You had no problems before 2 days ago when you changed the fuel filter?

Q: When you first go out in the morning (or after the truck has been sitting for a while), can you bleed air out of the fuel filter housing?

Q: The truck only has this issue when it has been sitting... it doesn't stall on you?

Q: When you get the truck running, open the brass T-handle valve located above the #1 cylinder in the front driver's side part of the engine. There is a bleed hose coming off that valve that runs down... does fuel come out of there when the truck is idling and you open the valve, or does the truck stall?

See about answering these questions right away so we can see what's going on... remember, we can't see or hear your truck, so be descriptive and accurate in your answers. If you aren't sure about something, ask.

Jim

 

[JiFaire]

LOL... see? You got two great guys stopping by already to give you a hand!

 

[2fastforyou]

I have had the problem of sometimes air in the line and had to bleed the filter lid bleed off. It will just shut off somtimes going down the road. Most of the time it will refire and go but this time I can not get it ot fire. After trying to start the truck and nothing I beed the filter and yes there is air. It does stall on me all the time. Thanks Guy I know you will help me get this thing running, and as for my fuel line patch job..It is clamed on real tightand is on the back side of the lift pump to the tank..I beleive the LP on pulls 15 pounds of pressure rite?





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

- Year: __1997___
- Truck model and class (ie: c2500) __1500 GMC sub_______
- Automatic or Standard auto_____auto_____
- Mileage: (indicate miles or km) ___88,000______
- Replaced parts and mods (IP, PMD, chip/PCM, TM, injectors etc) _na
- Model: ‘S’ or ‘F’ engine, NA or Turbo, EGR? ____has turbo__________
- Ambient outside temp: (indicate *C or *F) ____70______
- What fuel are you using? (#1 Diesel, #2 Diesel, Bio, VO, WVO, etc) __1 or 2_____BP diesel__
- What fuel additives are you using? ___none________
- Where are you located? _ohio____________

General maintenance: inspect and evaluate the condition of each. When were they last changed?
- Air filter ____ggod_____
- Fuel filter ____new_____
- CDR Valve? ___?______
- Coolant – last flushed/replaced at _____good________
- Oil – synthetic/regular, changed at _regular ______good, just changed____
- Batteries – state of charge, (matched set) replaced at ____charger 100%_________
- Battery cables and grounds (removed, cleaned and tightened): ________today cleaned______
- Glow Plugs - how many miles on them? ____not sure_____ What type? _____________
- Injectors - last changed at ___not sure____________


History: (Describe how the problem first appeared.)
- What were you doing when it happened? ____starting__________
- How was the truck running fine before this problem appeared? ________no_____
- Has this problem ever happened before? _______not at bad..will start after bleeding fuel filter_______________
- Describe any related factors that might be part of the problem. __been stalling while driving, will just shut off while running____________
- Have you checked for DTC (Diagnostic Trouble Codes)? (Y.N) _n___ And? ________


Diagnostics:

1] Starting:
1a] Does the engine start? ___no______
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? __comes on and goes out about 4 times_______
1f] Does your glow plug light come on? ___just wait to start______ For how long? __ seconds_______
1g] Do you see smoke from the exhaust while cranking? What color? __no..white when first starting then black_____

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) ? ____not checked_____
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? ______not tried___
2e] Do you hear a vacuum (hiss) when you remove the fuel cap? ____no_______

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

4] Stalling Issues
4a] Do you experience stalling only when hot? __no all the time__________
4b] Does it stall under particular circumstances? (ie hit bump, or on accel) ______
4c] Does pouring cool water over the IP seem to help with restarting? _________
4d] Is stalling momentary (engine recovers)? _________
4e] Does SES light come on when engine hiccups? ___no______
4f] Does cruise control quit working when engine hiccups? __no_________
4g] Does re-starting seem to reset engine, restoring cruise and power? _________
4h] Changes to dash lights or instruments during stalling events? _____no______

5] Running Issues
5a] On cold start, does upper rad hose get hard before engine warms up? ______havent noticed_
5b] Any bubbles or oil film in coolant overflow tank? ______
5c] Any white slime on oil surfaces (dipstick, CDR, oil Fill cap)? __________
5d] Excessive white smoke from exhaust on cold start? _one puff________
5e] Excessive black smoke from exhaust under hard acceleration? __yes. when towing hills________

6] Performance Issues
6a] Do you have gauges? ___yes. temp gauge stopped working________
6b] Maximum boost under load? ____________
6c] Have you added a performance PCM (reflash) or Chip? _no_____________
6d] Have you changed exhaust / downpipe / crossover? _
6e] Wastegate – mechanical or vacuum? ______________

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? ____no________
7d] Have you replaced the fan clutch? Manufacturer of replacement? ____no____
7e] (winter) Have you tested your antifreeze? Good to what temp? __________
7f] (winter) Are you using a winter grille cover? ___havent had it in winter yet________

 

[JiFaire]

Try the test I recommended above, opening the brass T-handle with the engine idling.

Your Lift Pump 'pushes' fuel from your tank, to the filter manager, to your IP. If the Lift Pump is working properly, and the line from the tank to the LP is not leaking, you won't get air in the filter mgr.

That you are either means your lines leak (between the tank and the LP) or that your filter manager is leaking, or that your LP isn't working when the truck is running - Oil pressure switch most likely suspect.

Try the test, get back to us.

 

[Veg_Out]

2 Fast, if you are unsure what a PMD is, I think we may have a possible culprit. It is a little black box on the side of your injection pump. It is the most widely known failure point on your rig.

It'll just shut off for no reason, like somebody flipped the key. It is easy to fix, with a new PMD and an extension harness.

It's just a guess you read on the internet, but fairly educated guess.

 

[JiFaire]

Bad FSD won't air-up the filter mgr, though...

 

[2fastforyou]

Now that i know what the PMD is , it was replced 4 weeks after I got the truck..bought one off ebay for half the price...I will try the T test if I can get the truck runng again.

 

[JiFaire]

Was your PMD new or used, and where is it mounted? It still won't cause air in your filter manager, but it could also still be an issue - Veg-out is 100% correct on that account.

 

[GM Guy]

One thing to remember is that air molecules are smaller than diesel molecules. therefore, if your lines are rusty, or questionable in any way, there is the possibility that you are sucking air, but have no fuel leaks.

(This is a similar issue on Ford PSD, apparently there are many connections in the fuel line, and it will suck air, but not leak. that is why sometimes a PSD sounds/runs like crap on startup)

This is a lesson learned here in farm country, as JD articulated 4wd tractors suffered from this fuel line issue.

Good luck, and happy wrenching!

 

[Matt Bachand]

I believe stock lift pumps put out 4-7psi. Which is Perfect for these trucks. 15 would be too much pressure for the injection pump.

Also, when I had a clogged up fuel tank sock, my truck would stall, and when I cracked the bleeder it HISSED, but the HISS was a vacuum releasing, NOT air escaping. I verified with fuel pressure gauge, the IP would suck and suck until it vacuum'ed the fuel lines and filter manager.

If that helps you think about it from another angle.

 

[guybb3]

Also, when I had a clogged up fuel tank sock, my truck would stall, and when I cracked the bleeder it HISSED, but the HISS was a vacuum releasing, NOT air escaping. I verified with fuel pressure gauge, the IP would suck and suck until it vacuum'ed the fuel lines and filter manager.

If that helps you think about it from another angle.

This is the direction I was thinking. My Sub sounded just like 2Fast's. What did the tank sock look like when you changed tanks, 2Fast? Did you change tank socks and maybe get a gas one by mistake??

 

[2fastforyou]

Well Im out of time missed a race tonight because of this truck not running...I have replaced everything up to the pump and it was new 8 months ago. I replace tank, pick up, sending unit, lines to the pump and still nothing...after I put the tank back in today the truck fired and ran for about 20 seconds then shut off. I really dont have tome to do this forum because I cant sit infront of this computer all night..working on race car..I would really like if someone that knows about this 97 sub GMC would call men the phone at 330-383-5035 asap...it would be so much easier for me this way and hopefully I wont miss tomorrows race because of it. Thanks