Loss of power

[mychevytruck]

While driveing my 94 chevy 6.5 turbo i lose power.I will be driveing at any speed and the truck will sound like it is spark knocking then loose all power.It almost seems like it is running out of fuel.
This happens randomly.sometimes for a few days it will be fine then others it will happen all day.

I have changed the fuel pump and filter.new PMD about 2 months ago,new air filter new glow plugs,gp cyliniod,crank censor.
Any idea's on what to do next?

[M123KT-450]

Have you changed your

OPS yet ?

If its starting to fail your lift pump will randumly cut out here n there...

I have my lift pump on a toggle flip switch once I forgot to turn it on and that is how my truck ran most the way home till I relized the switch was off...

Mike

[brokenparts1]

I agree, start with the ops. That is how mine acted when it went bad. If that doesn't fix it check the sock filter on the end of your fuel pick up in the tank. Mine has plugged with crap several times over the past few years. I clean it out with carb cleaner, but Walt also sells new ones.
Good luck.

[M123KT-450]

Say broken sounds like you have a case of algea !

Nasty stuff kills injector pumps...

Diesel Injection Service sells a product called Biocide get some of it and grab a few fuel filters I'm halfway threw the bottle and have noticed a performance increase already my algea content is down 80% from what is was...

Mike

[RipnRun]

Mine was acting in a similar manner. Changing the ops and lift pump relay fixed it (also tighten pmd screws, of course).

[mychevytruck]

OPS is abreviation for?
Sorry still learning some of this stuff,but hey we all had to learn sometime.Right?

[94K30]

OPS is abreviation for?
Sorry still learning some of this stuff,but hey we all had to learn sometime.Right?

Oil Pressure Sending Unit By the way, only use a AC Delco one... the rest don't hold up

[M123KT-450]

Oh I don't know ! I think I'm just as good as any AC delco ops !

lol Sept when I forget to flip the switch lol

Mike

[k3500man]

i need to know where said ops is, i cant seem to find it so i can change it out...

[trukdoc]

...of block on drivers side under glo-plug controller...same place as oil sensor on v-8 gasser...

[mychevytruck]

Thanks for all the help...changes the OPS and it's doing awesome!
The OPS is directly under the fuel filter houseing,and surpriseingly easy to get to.

[jessewieb]

96 k2500 suburban 4x4 while traveling at speeds above 55 mph my sub will start chugging, it feels like the pump shuts off. however if I push on the pedal it takes off. I have changed the ops and the vss (vehicle speed sensor). At lower speeds the sub acts normal. Only other thing I have done is remove muffler and cat.

[grancito]

Try some additive in the fuel that removes water.

[jessewieb]

I have now replaced the lift pump which has lower psi than the original about 4 @ idle and 2.5 when at 2000 rpm. Suburban still chugs bad, hard to drive above 60 mph. When I try to maintain speed (60 mph +) the engine will will rev up and down between 1500 rpm and 2000 rpm. However if I keep accelerating the engine will run smooth and gain speed. It chugs at lower speeds but is not as erratic.




1996 2500 sub 4x4 pmd isolater,#9 resistor,cooling upgade,airbox upgrade,ops,lift pump,wastegate sol and muffler and cat have been removed.
207,000 miles