Hey everyone ,I started the truck backed up and it died like i shut off the key. Know it just cranks .I looked back through some old pages but didn't see any thing.It has been starting a little hard lately also I have gotton a small skip every once in a while.Any and all help is greatly appreciated since I have to drive to work tomorrow! Thanks Kurthttp://www.dieselplace.com/forum/smileys/Cry.gif

Checked Supply pump? Try unplugging optic sensor, it will put you into extended crank mode, but if it does start then thats your problem. Only other real option, and unfortunately the most likely one is the PMD on the pump has failed.

Where is the optic sensor ? down on the crank? I will go out know and see if the pump is running.

The fuel pump is making a click sound like a solenoid on and off no buzzing though!

The optical sensor is on top of the IP, don't forget to check fuel pressure/supply pump operation. Jump the fuel pump relay between the common and powered wire (orange to grey).


Without the lift pump hard starting is eneviable.Edited by: quantum mechanic

Fuel pump clicking? that sounds more like a glowplug relay cycling to me. have somebody cycle the key, crank the engine or jump the relay while you crack the filter bleed behind the intake manifold near the firewall.

allright i have been looking and can't find where the fuel pump relay is! Can you point me in the correct direction.

alright no fuel is coming out of the fuel bleed on top of the fuel filter and I don't hear any fuel pump noise ! Supply Pump?

If you checked it cranking and the pumps not pumping, then thats what you need.

ok Thank you very much .Also i never had the pmd go yet what usally happens when it goes? Thank you so much!!http://www.dieselplace.com/forum/smileys/Hug.gif

similair symptoms. 5/8 and 3/4 wrench and about 10 minutes is all it takes to change supply pump. You going to try and change it tonight?

yeah I am gonna pull it out know and see if my wife can get me one tomorrow!

hey hammer,


Take the cover off your fuseblock under the hood and jump the fuel pump relay in there. It's like top rt corner to bottom left. If you look at the fuel pump relay you can figure it out based on the diagram. It should pump without key on.


I did this to prime the filterbowl on the 96.Edited by: quantum mechanic

Good deal, I would reccommend an OEM or Delphi replacement one, we sell Delphi and never have any trouble with them. I've seen several Carter pumps fail though, so steer clear of them.

The Fuel pump relay is labeled on the underside label of the lid, it will be the only gray relay in there.


- - X


X -


Looking over the fender, these are the two you want to jump to run the pump, with the key ON.

thanks TDG for the help I get the standard 20% off at the dealership because I work at a body shop so i will call the dealership first thing! Qm thanks i found the relay . When this kind off stuff happens I get all agrivated it is awsome to have help thrown my way!

So, what happened when you jumped it? Nothing?

Nothing happened when i jumped it so the pump is coming out

I had to make sure, the lift pump get's replaced and then the OPS because it powers the lift pump while the engine's running.


Some miss the relationship. The local parts store didn't beleive it controlled it either.

what is the ops? and do i need one?

Oil Pressure Switch, 6.5s use this switch to operate the lift pump. When they fail the lift pump won't run. But if you can't run the pump by hot wire, then you need a pump.

i will check that also! tomorrow

The oil pressure switch controls the dash guage and the lift pump. It is better to relay the lift pump swtched by the OPS or run an ign. wire to it. When you get a new lift pump on you can test the OPS by whether or not the pump makes pressure whle the engine's running.


open the bleed with it running and it should shoot out fuel.

Be sure to hold your finger over that fuel line when you crack that pump off of there. Diesel here, diesel there, diesel everywhere, whilest you are grabbing for that wrench that's just out of reach.http://www.dieselplace.com/forum/smileys/Big Smile.gif

i used a carter pump when i changed mine. it was whatever napa sells. hopefully it keeps working for a while.

Good luck, I hope it stay working for you for a while. I shouldn't say they're bad, I just notice a lot of the ones we replace are Carters, just as many are OEM originals with a ton of miles, never replaced a Delphi one.

Be sure to hold your finger over that fuel line when you crack that pump off of there. Diesel here, diesel there, diesel everywhere, whilest you are grabbing for that wrench that's just out of reach.http://www.dieselplace.com/forum/smileys/Big Smile.gif


You want to loosen the cap before removing the lines from the pump. If there is pressure in the fuel tank, it will come out all over you http://www.dieselplace.com/forum/smileys/HiHi.gif.

Allright here is how my day went ! Took the suzuki Hayabusa to work today and had the rear tire go flat on me at 120 mph.Luckily the bike tracked straight until i tryed to turn or go to slow. The wife brought me out my dragtire i put that on to get home. Got home put the fuel pump in after i loosened the fuel cap bled the air out the filter and it started up http://www.dieselplace.com/forum/smileys/Clap.gif. Back up and running Thanks again for all the help!

hey hammer,


What boost are you making?

when i first get on it ,It goes to 11-12 then drops to 7 when the solenoid dumps the boost The intercooler is not hooked up yet I have been playing with the plumbing because there is not alot of room with the half ton.I did port the intake as well.

If you havn't read turbine doc's intercooler install, it's worth it. He has a 1500 and (depending on what intercooler you have) had to deal with the same plumbing and clearence issues.


Stock chip? No boost fooling or tm?

Stock computer(no chip in mine) And I don't know how to fool the boost yet .What is Tm? Also what is a supper cooler? This site is awsome my brother has a duramax all done up he is on here as well.

TM = turbo master


Supercooler is intercooling with A/C system. That is, I have a second evaporative core in my truck's A/C system and a manifold around it with my intake going through it.


boost fooling is easy.


It isn't the solenoid that dumps boost. The wastegate solenoid is controlled by the wastegate dutycycle. When you resist the MAP and baro reading(on '96 newer it's the same sensor) the wastegate duty cycle increases. My resisted cycle runs 99.7% at idle 75% at 2000 rpm 60% at 2500%.


Stock is 65% WGDC at idle and drops fast as you accelerate.Edited by: quantum mechanic

The supercooler sounds cool! Alright how do i fool the map and baro? I never new how much boost got dumped until i put boost guage on and then i thought the guage wasn't working at first but soon realized the guage worked fine.I am used to Buick GN's that build good boost and then there is the 6.5!

I just put a pot on mine and it works beautiful and cost under 10 bucks. Go to Radio Shack and get a 10k linear Potentiometer (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=271-1715), they will have a few different contol knobs (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=274-415) to choose from, and you will need to cut the shaft a shorter so you can mount it in the dash somewhere. The map sensor is the black plastic piece on top of your intake plenum from the turbo. Unplug the white plastic connector, cut the middle green wire and soder on two wires (I used speaker wire) and run that through the firewall. Soder those two wires up to your pot, mount the pot wherever you want it put your knob on and your done.


I reccommend the 10k because it will allow you to make PLENTY of boost and won't set any codes.Edited by: Texas Diesel Guy

I was just reading that in your other post that is neat I love gagets and knobs as well I guess I will be going to Radio shack this week!

They have a micro that you don't have to cut. $3.99





If you want more boost(1-2 psi) at a lower rpm, soder in a fixed 10K in addition to the pot. when you put it in overdrive at 70 you will make 12 psi. Put 5K-10K on the baro and get 14 psi sustained at 70 mph.Edited by: quantum mechanic

I didn't see any there, but that would sure be nice. 10k pot will run more boost than I want which is perfect, now I can tune it in to match fuel increase from IP.


I'm gonna have to start looking for a Pyro now....Edited by: Texas Diesel Guy

how about wiring leds (light emitting diodes) into the dash for pyro and IAT guages.


The controller would be the hardest part.