I HAVE A 95 GMC Z-71 WITH A 6.5 TURBO DIESEL . I RECENTLY REPLACED THE PMD WITH A COOLING UNIT TO START . THEN THE OIL PRESSURE SWITCH AND THE LIFT PUMP .CLEANED THE K/N AIR FILTER AND RE-OILED IT . THE TRUCK RAN GREAT AT FIRST(FOR ABOUT AN HOUR TOTAL) BUT WILL NOT RUN ANYMORE . THERE IS FUEL COMING OUT OF THE T HANDLE AND OUT OF THE TOP OF THE FUEL FILTER WHEN I CHECK FOR PRIME . THE MOTOR TURNS OVER GREAT BUT WILL NOT FIRE . I CHECKED FUSES HOSES AND CONNECTIONS RESET THE ECM THROUGH PULLING THE FUSE BUT NOTHING HAPPENS .I CAN HEAR THE LIFT PUMP WORKING ALSO . THE BATTERIES WERE DISCONNECTED WHEN I REPLACED THESE PARTS SO EVERYTHING SHOULD OF BEEN SAFE . IM LOST , I HOPE SOMEONE CAN HELP

is fuel coming out of the injectors. is the timing correct, it could of been messed up when you reset the ECM. do you have a techscan to check it. that would be useful. also turn off your caps because it seams like you are screaming

Woody35's Sig:

1997 Chevy K1500 4X4 EC/SB L56 6.5 Liter Turbodiesel
2100 PSI Pop Pressure Bosch Injectors, Bosch Duratherm Glowplugs, Relocated PMD,
Steel Braided Oil Cooler Lines,Custom Steel Vaccum Lines,Tekonsha Voyager Brake Controller
ARP Headstuds, .010 Thicker Gasket , 265/75R/16 UniRoyal Liberators A/T

crack one of ur injector lines open while you have a buddy crank the engine. If no fuel, it could be that you got a faulty pmd, the extension harness(if relocated out of the engine bay) could be faulty, or your injector pump took a dump.

Thank you ill try that . But it makes no sense to me what is going on because it was running fine after I replaced these items and then all of the sudden it wont run . Thank you again for your help and if you have any more suggestions that would be nice .

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Thank you ill try that . But it makes no sense to me what is going on because it was running fine after I replaced these items and then all of the sudden it wont run . Thank you again for your help and if you have any more suggestions that would be nice

Did it quit while running? Or just not start up next time? I would probably suspect the pmd the most but not always. Check the shutoff solenoid also. When you turn the key on it should click. After that you will need the intake removed to test any further. I would also check for codes. Could be a bad encoder.

wtfd6's Sig:

2000 Ram3500

It kind of did both . The truck ran fine on last friday but would not start saturday morning . It attempted to start but would not stay running for more than about 10 seconds . Now it wont even attempt to fire . It turns over but wont start . I wonder if the new oil pressure switch that I replaced is faulty because the gauage inside the truck now fluctuates all over the place . Can you tell me where this cut off switch is located ? The truck is throwing codes but my mechanic said that these were basic codes and their nothing that should affect it this severly . Thank you very much for your input !

It is under the intake manifold in the valley. Not exactly easy to get to.

just loosen 10 or 12 bolts a couple clamps and you have unbolted your intake manifold.

I cracked the injector lines and no fuel came out . I swapped out the oil pressure switch with a new one . I popped the sock off the in tank fuel pump by using an air commpressor . Checked the fuel cut off switch that is mounted on top of the injector pump and it works fine . There is fuel getting to the pump but none is coming past that point . I also checked connections to the pmd , they are also fine . So does that only leave the pump? I heard of a optical sensor thats located in the pump itself , they say this part is not servicable . Can you explain what im looking for when i remove the intake manifold ? Also I was offered 1500 dollars for the truck not running , should i take the money or is it worth fixing the truck ? I just wonder if these problems are likely to continue after putting the money into it .

it looks like someting is wrong with your injection pump. go to a pump shop to get a recommdation on wither to get a new one or get your present one fixed. when you lift your intake manifold you will see a injection pump with 8 lines coming out of it. optical sensor is not servicable because it is inside pump i think. not 100% posive.

ive never seen your truck so i dont know what type of shape its in so if 1500 dollars is a good deal or not. as far as it runs after a new injection pump, move PMD, and other mainetance items it should run forever as long as nothing is catasrphocially wrong. sorry i cant spell tonite

optical sensor is serviceable. I've never messed with it but many have for a little more fuel.
Was your old PMD bad? You could put the old one on the extension harness and then try without the extension. Just a thought since your running out of options.

FastCR's Sig:

1995 Chevy K2500 Extended Cab Long Box P Pump 12 Valve + NV4500 + Military 37s
215s, No fuel plate, star wheel all in, WG shut, Southbend, stacks, some other stuff
'08 LMM 6" lift, 35's, blacked out, etc. (dads)
'02 VW Jetta TDI (All stock except deck)
I got a pocket full of bread a girl givin' me in the back row at the movies

The optical sensor is serviceable by a pump shop only. It will change the whole calibration. Can you find out exactly what the codes were? From the sounds of it you need a new injection pump. I wouldnt know what to say as to whether $1500 is good for your truck. I havent seen it either.

Whoa ya'll jumping to IP swap already, a bit premature. lots of other stuff to do, you said swapped PMD, with new or new used, what remote locator kit did you use?

bad OPS will not prevent a start unless you have air in the system and the IP can't pull it's own fuel.

These are fly by wire controlled truck, which means it needs "clean-tron flow paths" to get proper voltages to PCM ands devices that talk to the PCM.

Have you checked that fuel shutdown solenoid on top of IP is opening, are ALL ground connections clean and tight, not just the ones going to the battery, Optic sensor is a field replaceable unit.

have you checked for positive lift pump output, at diagnostic connector pin G, apply +12v to that pin and lift if healthy will run, you also need to put a test vac/press gage on the drain outlet tee of filter manager to see how much lift you are seeing.

Rarely if ever does a IP just quit, when they go bad they have driveability issues, straight up no starts are 99.9% of time not caused by the IP itself.

Turbine Doc's Sig:

98 K1500 GMC, Heath reflash, ATT, 3:73, 4L80, 4" exhaust, S to F conversion, Balance flow cooling, Heath fan-pump-clutch, FTB mod, Derale trans cooler, Heath WMI, lots of other goodies, last dyno before adding some more goodies 197 rwhp, and 390 rwtq, not huge numbers but very good for a 6.5. estimated 225 +/-rwhp at this juncture, 410-430 rwTq. Much BTDT experience with the 6.5

Thanks for all the info guys . To answer some questions , it was a used pmd and im not sure what kind of remote kit . Im sort of broke so i bought them off of e-bay . But im sure their not the problem because the truck had drivability issues even though I replaced these parts , nothing changed . But after i replaced the lift pump and ops I noticed a tremendous difference it ran like crap at first but that was do to air in the lines because i forgot to purge the air . After the air was purged it ran like a new truck . It sat overnight and still will not start . I think that i might have to break down and take it to a shop because I have tested everything that you all have told me but I dont know how to check the electronic stuff . I need to get my hands on a real mechanics manual for this truck because chiltons aint cuttin it no more . Thank everyone for all your help and if ther is any more info im willin to try . By the way how much should it cost for a pump re-build .

Ops? You replaced the encoder(optical sensor)? The pump needs calibration after that is done. I know the broke feeling believe me. Hopefully you get her up and running soon