Hello, I have a 1997 6.5l turbo diesel Silverado, Recently I noticed that my truck will sputter and loose power going up hills or occasionally when I really stomp on it to pass someone. (Mostly hills though). It runs perfectly down the highway at 65MPH with the cruze on. Mostly just going up and down hills in town is where I have my problems. Any way its like its starving for fuel so I thought it was just a fuel filter, so I changed it... but its still happening. Finally I came outside from work yesterday and it didn't want to start, I played with the bleeder on the filter (don't know how it works) and it had a little pressure in it, I finally pumped the gas pedal like crazy and held it there and it started up. but didn't smoke like it normally would if u cranked it and it was getting too much fuel.

Is these a primer pump in the tank that could be going bad? The injector pump on the top of the engine was just changed not all that long ago... (like a year or so ago).

Please help as this is my only way to get to work.. (I am still driving it but don't trust it).

I also want to add, that though we have had some hot weather lately. I live in VT and we pretty much never go above 100 degrees in the summer...today is cool like 50 degrees and it still did it... so I don't think its temp related.

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Also ... is there a pump in the tank or just a lift pump on the frame? Is the tank / frame lift pump only for starting or needed all the time?

I don't think is a pmd because I live in a cool area and I don't think it gets that hot..

 

Pump mounted driver is bad if it hasnt been relocated

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Only sending unit in tank. Lift pump on frame runs of your oil pressure switch witch both are prone to failure. Only use ac delco parts for replacement

 

so u don't think I should even replace the ift pump on the frame and try it?
think I should definatly get a new pmd and relocation kit? I don't have much money here and I am hoping its not the pmd.

 

Check lift pump before just changing parts,with truck running open the T valve up by oil fill spout and if there is no fuel shooting out the hose connected to it and it dies,your lift pump is bad.If it shoots fuel it is working.If your PMD is still on the side of your Injection pump get a new one and relocation kit with heat sink and extension cable.

 

I replaced my lift pump and it still dident work, I just ordered the new (well used) pdm and relocation kit off of ebay. If I keep the truck under 2k rpm it runs good enough to get around.. and starts hard sometimes... looses power / boggs up hills.... does this sound like most people PDM sysmptoms... ? Anyone have any pictures of where they relocated theirs... and what the "Resistor does"? do I need it? If so ill try and take it out of my old one....

 

Did you test the lift pump before replacing it? 90% of the time, the oil pressure switch goes bad and that causes the lift pump not to work.

and yes, transfer your resistor to the new pmd. mount the pmd behind the bumper. relocating it anywhere in the engine bad will not help.

 

No I actually didn't test it, but I had one so I just changed it.... I am hoping after I get the new pmd and mount it behind the bumper my truck will be fixed.... its running really odd... do the symptoms sound correct? If I keep the gas to the floor and crank it it starts...

 

Removed my old PMD and the resistor in it... now waiting for my new PMD and relocation kit.
I am planning to use Thermal paste like on a computer processor and heat sink... do most people d that or simply just bolt to the heat sink and forget it?

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btw I found this pink pad under it.... instead of the black GM one... looks like someone else replaced the PMD before but never relocated it.
This ss diesel supply pad is what was under it PMD Installation Kit :: SSDiesel Supply :: GM 6.5 TD Specialists

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My cooler kit states it has a screw for a ground wire.... but I never removed my ground on the top of the injection pump.... do I need to extend a ground wire as well? I was gonna just mount that cooler on something metal .... like in the right front nostril hole on the front bumper?
Do I need to also ground it someplace else?

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well the guy sent me a dead one... wont even start my truck... so I am dealing with that now... He doesn't want to refund me.. He goes by the name joeyeraif on ebay.

 

The used PMD's are a crap shoot, it usually takes 3 trys to get a good 1 and after return shipping on the first 2 new is almost the same price.

The vendor is usually very good at sending replacements quickly if you return the dead PMD first in my experience.

Your symptoms sound like a combination of problems.
Plugged fuel filter?
Collapsed or aftermarket sending unit tank sock?

Bad lift pump?The LP test of opening the water in fuel Tee valve while the engine runs is a good indication of LP performance stall with valve open is a fail and further diagnosis is required to eliminate the LP or a restriction in the tank-even a bad/wrong fuel cap can restrict fuel flow to the IP if tank vacuum exceeds the LP ability to pump-try running with the cap loose or check for excess vacuum when you remove the filler cap after it has been running for a while.

Bad OPS-AC Delco ONLY for replacement!
Also google "OPS relay mod" for long term reliability or buy the kit from Kennedy Diesel.
Low or no boost?

Adding an additional ground from the PMD heatsink to the IP or drivers side battery ground while not required is an option that is encouraged by some.

Also use heat transfer paste or the pad between the PMD and the heatsink but not both-torque PMD mounting screws to 25 inch pounds.

Air intrusion in the fuel system between the fuel level in the tank and the LP can also cause problems,replace the IP fuel return hose with clear diesel rated tubing and with the truck safely parked watch the hose with the engine idling-bubbles indicate air intrusion.

If your LP is not working air intrusion can happen anywhere since the whole system is now under suction.

 

You were right on on all of that with used PMDs... I am also now thinking its the sock in the tank. I replaced the fuel filter, the lift pump, the PMD and relocated it. I am gonna drop the tank next and change that sock. I honestly think that's defiantly the problem. I also need to look up that OSP relay mod, your mentioned....