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Old 10-25-2006, 11:05 AM   #1 (permalink)
Hooky
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Sputtering 6.5

Guys:

A few days ago I noticed my 95 model 6.5 would miss or sputter a bit while sitting at a stop sign. Changed the fuel filter and put in a can of Valvoline fuel and injector treatment. I used a hot jumper to operate the lift pump to remove air from the filter canister via the bleeder valve. The lift pump appears to be working good. After a test drive, the problems appeared gone. I drove the truck this morning and after about 10 miles it started sputtering and missing bad at a idle and eventually began dying. I was able to get it started back by pumping the accelerator but I would have to put it in neutral and keep the rpms up to keep it running.

Last year my pmd failed and I relocated that pmd (after retightening the transistor nuts slightly) to outside of the engine bay. I have had no problems with that PMD since. Any chance this is the retightened PMD failing or does this problem sound fuel delivery related???? Help!!!
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2005, Chevy Silvarado 2500HD, 6.6 LLY Duramax with Allison, Undercover Tonneau Cover, Line-X Bed Liner, stock muffler delete with replacement Magnaflow, 5.3 airbox, no mods yet 65,000+ miles for now. 2002 Ford F-250 with 7.3 Powerstroke, Superchip, no mods, Undercover Tonneau Cover, 91,000 miles.
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Old 10-25-2006, 11:38 AM   #2 (permalink)
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Sounds like a fuel problem to me. Probably OPS, since hotwiring the pump already proved that it works.

Go thru the diagnostic checklist and see what you find out. Diagnostic Checklist version 2.0 [10-2009]
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Old 11-19-2006, 05:36 PM   #3 (permalink)
Hooky
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Help ..... 6.5 Mechanics

Quote:
Originally Posted by Hooky;1372227;
Guys:

A few days ago I noticed my 95 model 6.5 would miss or sputter a bit while sitting at a stop sign. Changed the fuel filter and put in a can of Valvoline fuel and injector treatment. I used a hot jumper to operate the lift pump to remove air from the filter canister via the bleeder valve. The lift pump appears to be working good. After a test drive, the problems appeared gone. I drove the truck this morning and after about 10 miles it started sputtering and missing bad at a idle and eventually began dying. I was able to get it started back by pumping the accelerator but I would have to put it in neutral and keep the rpms up to keep it running.

Last year my pmd failed and I relocated that pmd (after retightening the transistor nuts slightly) to outside of the engine bay. I have had no problems with that PMD since. Any chance this is the retightened PMD failing or does this problem sound fuel delivery related???? Help!!!

Guys:

Since submitting this thread (see quote) I have run a few diagnostics on my 6.5. Checked lift pump (via lift pump test) and it appears to be working fine. I have purchased another lift pump but I don't feel I need to install it now. Removed fuel intake line just before where it enters the IP. Reprimed to this point by running lift pump to purge any air. Attempted numerous times to restart and finally after 15-20 times over a 45 minute period, the truck started. Before starting, it would hit like it wanted to start, but just would not catch and run. When it did fire up, it ran very rough. Kept rpms up around 2,000 to keep it running, but it was still sputtering and would not idle for more than a few seconds. I was able to recrank by rapid pumping accelerator, and when the engine would try to die, and few quick pumps on the accelerator, and it would catch back up. Trucks acts like it has air in the system (no vacuum on the fuel cap) but after 20 minutes of running @ 2,000 + rpms, still no better.

Also, rechecked to see if it would run with a different PMD, no difference, still rough, sputtering and dying when trying to idle.

Does this sound like the injector pump is bad or some air in the system????

If injector pump is the culprit, any ideas on the best deal on a replacement pump???

Thanks, Mark
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Thanks, Hooky.

2005, Chevy Silvarado 2500HD, 6.6 LLY Duramax with Allison, Undercover Tonneau Cover, Line-X Bed Liner, stock muffler delete with replacement Magnaflow, 5.3 airbox, no mods yet 65,000+ miles for now. 2002 Ford F-250 with 7.3 Powerstroke, Superchip, no mods, Undercover Tonneau Cover, 91,000 miles.
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Old 11-19-2006, 09:23 PM   #4 (permalink)
knkreb
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Any check engine codes? OBD 1 can be checked with a paperclip - easy peasy.

Go to diagnostic checklist below in signature or top of forum sticky. Go through and post all info. Most times you'll have it pegged before posting back, but if'n not, post back with info and we can go from there.
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Look here-> GM 6.5 Reference Material & FAQ's <-Look here

Diagnostic Links & Common Failures: Turbo System * Lift Pump/OPS * PMD * Stalling


°Please include your vehicle details in your signature line. Did you read the FAQ's and search before posting?
*Bus 1, rest in peace. Bone stock, now just bones. 4.10 rear 10/13 mpg, 182,000 miles with a set of MCI motor coach seats.
*Currently driving an "Canadian Camo" Snow White 2001 5.7L Chevy Express.
*Bus 2, 99 7.3L PSD.
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Old 11-20-2006, 07:47 AM   #5 (permalink)
fltech
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Sounds like air in the fuel, get some clear tubing from hardware store (in plumbing section) and put that on the fuel pump inlet and see what you come up with.
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Old 11-20-2006, 05:18 PM   #6 (permalink)
Hooky
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Quote:
Originally Posted by fltech;1421580;
Sounds like air in the fuel, get some clear tubing from hardware store (in plumbing section) and put that on the fuel pump inlet and see what you come up with.
fltech: Are you suggesting splicing into the intake line where it goes in the top of injector pump with a section of clear tubing, and afterwards watching that clear line for signs of bubbles. My biggest challenge is to keep the darn thing running long enough to look at anything under the hood.

I plan to run the 6.5 diagnostics ans recommended in previous post. I have already troubleshot most of those items on that list, but not sure how reliable the lift pump test results since the engine was coughing and sputtering the whole time before and after opening the drain valve T-handle.

Thanks for yours and anyone's help, I sure don't want to invest in an injector pump unless it is absolutely necessary.
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Thanks, Hooky.

2005, Chevy Silvarado 2500HD, 6.6 LLY Duramax with Allison, Undercover Tonneau Cover, Line-X Bed Liner, stock muffler delete with replacement Magnaflow, 5.3 airbox, no mods yet 65,000+ miles for now. 2002 Ford F-250 with 7.3 Powerstroke, Superchip, no mods, Undercover Tonneau Cover, 91,000 miles.
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Old 11-20-2006, 06:06 PM   #7 (permalink)
Hooky
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Quote:
Originally Posted by knkreb;1420880;
Any check engine codes? OBD 1 can be checked with a paperclip - easy peasy.

Go to diagnostic checklist below in signature or top of forum sticky. Go through and post all info. Most times you'll have it pegged before posting back, but if'n not, post back with info and we can go from there.


1.Lift pump test - As best I can tell, pass, however engine is sputtering throughout the whole test and has to be maintained at above idle to run. Fuel runs freely when T-handle is opened while engine is running.

2.Service Engine Light - Off

3.Model year 1995, 1500, 6.5 turbo

3a. Odometer reading 141,000 +

3b. Miles on major engine components if been replaced Injector and lift pump replaced under warranty @ app. 70,000 miles

4.Do you have any engine codes? No, just 12 with the paperclip test.

5.If you do have engine codes - 12

6.Air Filter condition (visual check) Good

7.Fuel filter condition Changed with less than 25 miles on this filter.

8.Condition of Battery terminal connections clean and tight.

8A.Known condition and age of the batteries. both are hot.

9.Upon cold start, does the radiator hose get hard quickly? No, only after warm up does the upper hose get firm.

10.Upon cold start, do you have excessive white smoke? No

11.Do you have excessive cranking time before the engine starts? Yes, engine will not crank unless accelerator is pumped, and then may not start for several attempts.

12.Have you used the block heater, and does this effect engine starting? Have not tried block heater, but problem persists in warm weather.

13.During hard acceleration, do you have excessive black smoke? No.

14.Do you have any unusual exhaust smoke issues? No.

15.Turbo check out - Can't keep running long enough to check this out.

16.Do you have an EGR on the engine? (An F or an S engine code) Not sure, is this represented in the VIN.

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

18.Indicate fuel that you are using: Bio-diesel, #2 Diesel, #1Diesel, SVO/WVO, other #2 diesel.

19.Are you using any fuel additives? Placed fuel additive in approximately 25 miles ago (Valvoline Synpower Diesel Injector Cleaner). Truck was doing this prior to using this product.

20.Please indicate geographic region you are in: (example: Texas or Canada) Southeast Arkansas.

21.Do you have any service history available that might pertain to the problem you are having? Injector and lift pumps replaced at around 70,000 miles. PMD replaced and relocated around 120,000 miles.

22.Please indicate any modifications to the vehicle that might help us diagnose better. Cat removed with flowmaster muffler, no other mods.

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


Any thoughts knkreb?????
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Thanks, Hooky.

2005, Chevy Silvarado 2500HD, 6.6 LLY Duramax with Allison, Undercover Tonneau Cover, Line-X Bed Liner, stock muffler delete with replacement Magnaflow, 5.3 airbox, no mods yet 65,000+ miles for now. 2002 Ford F-250 with 7.3 Powerstroke, Superchip, no mods, Undercover Tonneau Cover, 91,000 miles.
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Old 11-20-2006, 08:31 PM   #8 (permalink)
knkreb
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Thoughts, well looking maybe at PMD. Problem with PMD failures are there are no diagnostics except changeout to prove problem. Hate to say "change it" and still have problem, especially since yours is remote mounted away from engine heat. I would really hate to spend your money in the wrong direction.

If I read it right, yours has already failed once, and this is the same one in use that has failed before. If Turbine Doc chimes in, I believe he had one that he had failed and brought back to life once before in the "points to ponder how hot it gets" thread from yesteryear. If I remember, it did finally fail again.

Other thoughts, well, could be iginition switch failure. Located under steering column, not the key switch.

I'm thingking that the only way to really pin it down with out doing a parts change might be to use a scanner to see what happens when it fails. Dealership, fuel shop, friend, mechanic, or local dieselplace friend at top of forum sticky might be helpful.
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Look here-> GM 6.5 Reference Material & FAQ's <-Look here

Diagnostic Links & Common Failures: Turbo System * Lift Pump/OPS * PMD * Stalling


°Please include your vehicle details in your signature line. Did you read the FAQ's and search before posting?
*Bus 1, rest in peace. Bone stock, now just bones. 4.10 rear 10/13 mpg, 182,000 miles with a set of MCI motor coach seats.
*Currently driving an "Canadian Camo" Snow White 2001 5.7L Chevy Express.
*Bus 2, 99 7.3L PSD.
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Old 11-20-2006, 10:49 PM   #9 (permalink)
CharlieP.
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It sounds like the PMD to me. When it starts to fail it will give clues like a stall then a re-start with a stall further down the road. All this will get worse. The screws were already tightened once so I would think you're probably on borrowed time.
If you bypass the lift pump and get fuel to the IP than the truck will run. Unfortunately when this stupid thing fails it won't set a code for you. You got a flash code of 12, so you have no codes?
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Old 11-20-2006, 11:34 PM   #10 (permalink)
Hooky
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Quote:
Originally Posted by knkreb;1422751;
Thoughts, well looking maybe at PMD. Problem with PMD failures are there are no diagnostics except changeout to prove problem. Hate to say "change it" and still have problem, especially since yours is remote mounted away from engine heat. I would really hate to spend your money in the wrong direction.

If I read it right, yours has already failed once, and this is the same one in use that has failed before. If Turbine Doc chimes in, I believe he had one that he had failed and brought back to life once before in the "points to ponder how hot it gets" thread from yesteryear. If I remember, it did finally fail again.

Other thoughts, well, could be iginition switch failure. Located under steering column, not the key switch.

I'm thingking that the only way to really pin it down with out doing a parts change might be to use a scanner to see what happens when it fails. Dealership, fuel shop, friend, mechanic, or local dieselplace friend at top of forum sticky might be helpful.
Tried it with another PMD, still no change in cranking. Another diesel shop guy suggested that I blow the line out from the fuel tank side of the lift pump back through the fuel tank. He says that he has seen algae problems in fuel tanks cause fuel delivery problems stopping up the sock filter at the tank.
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Thanks, Hooky.

2005, Chevy Silvarado 2500HD, 6.6 LLY Duramax with Allison, Undercover Tonneau Cover, Line-X Bed Liner, stock muffler delete with replacement Magnaflow, 5.3 airbox, no mods yet 65,000+ miles for now. 2002 Ford F-250 with 7.3 Powerstroke, Superchip, no mods, Undercover Tonneau Cover, 91,000 miles.
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