is the pump a rebuild or is it actually new from the factory

 

brand new from factory

 

I am having the same problem with my 100,000 mile, '95, Chevy 4x4, Dually, 6.5 Turbo Diesel (electronically controlled) The PMD was getting hot, causing stalling and bucking. I took the PMD from it's plenum mounted heat sink, filled the transistor area with dialectric/heat transferring paste, added two phenolic 3/4 inch spacers betweeen mounting bolts, and the truck ran like a Lexus for 2 weeks and now only starts, runs for 5 to 10 seconds and cuts off. A G.M. Tech said to check for underhood relay, listed "fuel pump" to see if it was staying closed with ignition on and off, and it is, Is this relay energized by the ECM...sensors, etc, after a certain event is supposed to take place? When I open the contacts/points in the relay, I hear a click under the plenum, is this the fuel solenoid allowing fuel into the I/P? Weak to little fuel at cracked injectors, How do you bleed air out of this system if needed??? No leaks detected at all. I was told this truck is OBD-I not II, and it only gives codes, not re sets parameters, is this true?
I've had no driveability issues as read about the I/P going bad, and when it does stay running for 10 seconds, it runs great, smells normal, stalls. Fuel is strongly coming to I/P, found one way brass valve going into Racor stuck and barely allowing fuel through, removed innards' for testing purposes, aware of it keeping system primed. Recently replaced glow plugs of which half of them were missing half the electrode, but it started and ran fine with bad glow plugs for over a year, driving my kids from West Palm Bch, FL to Cocoa Bch. and back with a bit less than 1/4 of a tank. Any one know of a non dealership 6.5 pro in Palm Bch, FL area? Could a heated but subsequentaly good running PMD just go out as such, causing start/stall? I read that glow plugs in such poor condition results in timing advance and re flashing is needed...any help will be greatly appreciated, as I'm losing my ***, it is my work truck. READY TO DIVE INTO A 454!!! Thanks.

 

Gotta diagnose it fuel wise, thats the first thing to do. Start at the l/p. And work your way up to the injector. New parts can sometimes be duds too, and you could be fighting against multiple issues not just one.. Ive bought a used pmd before. it lasted me 1 month, then stalling all over again. You have to buy a new pmd. By chance did that used unit you bought have a resistor in the plug of the pmd itself? It has a small number on it also. That small resistor needs to be in there too. Tell ya the truth i dont think this pump rebuild will solve your issues, its got to be something else...

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That PMD should be directly mounted to the heatsink. No spacers, the heatsink "sucks" the heat out of the two big resistors on the PMD. That pmd is prolly bad now. But do check the l/p, you can jump it at the fuel pump relay under the hood.

 

'Slug,
Thanks for your input, to state my issue(s) a bit clearer. My PMD, per the previous owner, was recently re placed, but due to me experiencing highway bucking and stalling, I researched the importance of keeping it cool. The newer PMD, possibly now suspect, was and still is attached to a Sweedish made Heat Sink, Identical to most seen on such sites as this, on the top, Port side of the plenum top with two 1/2 inch bolts, metal to metal, with the trucks previous if not original PMD still being attached to the Port side of the I/P. To apply some mechanical skill, I removed the PMD, heatsink, and removed the PMD from the heat sink. Nothing came out of the PMD plug besides the plug, with no resistors stuck to it. I did not look inside of the plug hole to look for the resistors as the truck ran perfect for nearly 7000 miles on top of it's 100,000 purchase reading, assuming they were intact. I noticed how the two transistors underneath the PMD, were down in pockets, reducing maximum potential heat transfer from a poorly designed "FSD COOLER" which induced heatsoak while parked hot, being a metal to metal attachment point (two bolts ) atop the Port side of the plenum, intense engine bay heat, as well as the bare, black exposed PMD sitting inches from the top of the engine, I filled the transistor pockets full of heat trasfer paste (the tannish paste seen in all the electrical devices we fixed, but never worked again) then, using a new PMD/FSD heat transfer pad, re attached the pmd to it's heatsink, with little wiping of paste being needed from the edges. Further applying 5.0 Mustang experience, I installed 2 Phenolic spacers (the sandwiched fiber that reduces heat transfer, used on Mustangs as spacers between the upper and lower EFI intake, assisting in maintaining a cooler, more dense air charge.) Using Anti sieze, re attached the PMD and cooler to the plenum top. The truck fired right up and ran flawlessly for several weeks. Then came the starting and suddenly stalling issue, upon cold start ups. Being aware that my glow plugs were bad (glow plug light stayed on for 3 weeks until I learned how to clean up the glow plug solenoid-now working) electrodes were missing on the 5 which I replaced, not yet getting to the harder 3 on the passenger side. NOTE PLEASE: I read on several sites that if glow plugs such as mine were in such bad shape, the timing would be "greatly advanced by the ECU"...any truth to this you are aware of? I have replaced 2 starters in the recent past, part towards ignorance, part to the fact that on 3 out of 4 start/stalls, the truck eventually remained running perfect...until most of the next cold/luke warm re starts. Now at a loss, going to check all of my ground, especially due to my helpers grounding out my positive battery cable to the chassis...twice. ALSO NOTE PLEASE: I recently changed my oil, filter, and Racor fuel filter, with the truck running good afterwards, prior to the start/stall issues, but on the way home, after changing only my oil/filter, my truck held a 1000 rpm, and would not shift into overdrive, without several manual shifts. I've read how circuits such as the boost solenoid/controller, and other components are tied into transmission circuits and I'm wondering if old oil seen on Trans. connections could be a contributing factor. I have also attempted to start truck while being jumped as well as fast charged, also probably depressing the fuel and brake pedal at the same time, numerous times... throwing yet more codes as I read. Upon checking the lift pump, it was initially there, but weak. I removed the brass one way valve leading into my Racor fuel filter, which is before the lift pump, and the valve seemed so stuck, you could not blow or suck through it. Gutted it, now with air in injection pump (HOW DO YOU PURGE AIR FROM A '95, NO "T-HANDLE, AND LITTLE FUEL WAS PRESENT WHEN INJECTORS WERE CRACKED WHILE CRANKING, BUT IT ALLOWED THE TRUCK TO IDLE FOR LENGTHS OF TIME....WTF!??? PLEASE SHARE RE: PURGING AIR FULLY)
One final issue/question. While awating return of second starter, a GMC Tech told me to check the black underhhood relay, labled fuel pump...? and check for inner point contact remaining closed with key on and off, which it did stay closed. Upon carefully opening that contact, I heard a click/thud eminating from the I/P area. I was told this is the fuuel solenoid in the I/P which allows fuel to enter it. I read of importance of grounds on a great posting, will check all. Do you have any knowlege of this solenoid/relay issue mentioned. Could a tired, replaced PMD cause start/stall issues? Could the ECU not be energizing the mentioned relay due to other issues such as air in system causing optical eye not to read fuel present. Sorry for all the questions, I am a first time Diesel owner/Diesel Idiot, but with the vehicle being a 4x4 6.5 T/D Dually, loaded, I am trying not to drop in a fresh 454 HI PERF, 4 - bolt block (6 mpg) F' it if this B.S. continues on a 100k 6.5.
Thanks for your reading and assistance if possible.
B. Slattery

 

Ok, that PMD is a first major iffy. You are totally correct about the intake mounted cooler design. It should be mounted in a cooler place. But once a pmd is subjected to heat for any amount of time its a roll of the dice from then on out. BTW: I also own a mustang too, going to put a roller 351 in it this winter out of a ford lightning. I wouldnt see how the plugs not working would change the timing. I ran around with zero working plugs for 2 years starting it with ether (DO NOT RECOMMEND!). But i may be wrong on the timing... On the purgin thing when you get fuel to the fuel filter manager take out 8 glow plugs. And crank the engine over till a fine mist of fuel comes from the glow plug holes. THis is the way i did it with my new engine, however it will not get out ALL the air. The only way ot totally remove it all is to drive it around for a bit. IM sure your truck ran with hte injectors only cracked, it is still building up insane compression while cranking.. I dont think there is anything wrong with the relay, there are other way more common issues than that.... Ive never seen one go bad but ya never know i guess..

 

MY 1993 6.5 turbo chevy will start and run fine. But after it is shut off for 15 or 30 min

and you try to restart it, it is hard to start until it cools down.

I installed another fuel pump lifter but it stills take awhile to start after running.

Does anyone have and idea what is wrong? Thank you, glasspack

 

take bottle of water poor it over the IP next it don't want start when hot and then try starting if it start i would have to IP on it way out

 

1993 6.5 turbo Chevy Truck. 139,000 miles. Where is the IP located? And is it a big job
to take off and re-install a new one. It starts fine when it is cool but when I drive it
for 20 miles and try to start it 1 hour later it starts for 30 seconds then dies and I have
to pump the accelerator furiously to get it to started. Thanks for any help. Glasspack.

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1993 6.5 Turbo Chevy Truck. Well now the transmission is jerking when I start to accelerate and it will not shift but will run at 40 mph. The transmission oil is full and I changed it every two years. The oil doesn't smell burnt. Do you think a new filter and
oil change would be a place to start or just take it to a Transmission Shop. People say it
could be the valves are dirty or the bands are bad. Any suggestions? Thank you, Glasspack.

 

Make sure you regrounded PMD I relocated mine behind front bumper and had a ground wire left on top side of intake. My extension harness did not provide a ground cable