Still having fuel issues

[97duallydiesel]

The truck is running somewhat better now that I figured out that the Fuel filter was either cracked or wasn't tight and leaking air into the system causing it to stall and die.

I replaced the LP once again with a 93 LP, which wasn't that expensive. before I did this I checked the voltage to the LP with a volt meter when I turned the key on and it was reading 12. volts. I ran a new ground wire also, this was a problem before.

I decided to check all of my grounds and found one of the straps leading from the frame to the passenger rear was broken. I replaced that as well as the strap leading to the body. All other grounds where good.

I replaced the PMD ( Pensicola Diesel)and mounted it on a heatsync mounted to the top of the tranny cooler straps .( I removed the AC radiator awhile ago so there's alot of space between that and the coolant radiator)

Now the truck will sometimes start fine idle no problem but when I drive away it will stall. (Other times it wouldn't )I have to crank it several times and it will fire over and be fine. It will run no problem then all of a sudden hic-cup and get loud throwing a code P0251 .( Injection Pump Cam system) The truck still has power but it's almost like it's not getting fuel to all the cylinders.

My diesel mechanic says I need a new IP. I just want to make sure before I buy one. When I installed the PMD I put some dielectric grease in the connections . Could this be a culprit? Or maybe a bad wire harness??

 

[540s10]

The truck is running somewhat better now that I figured out that the Fuel filter was either cracked or wasn't tight and leaking air into the system causing it to stall and die.

I replaced the LP once again with a 93 LP, which wasn't that expensive. before I did this I checked the voltage to the LP with a volt meter when I turned the key on and it was reading 12. volts. I ran a new ground wire also, this was a problem before.

I decided to check all of my grounds and found one of the straps leading from the frame to the passenger rear was broken. I replaced that as well as the strap leading to the body. All other grounds where good.

I replaced the PMD ( Pensicola Diesel)and mounted it on a heatsync mounted to the top of the tranny cooler straps .( I removed the AC radiator awhile ago so there's alot of space between that and the coolant radiator)

Now the truck will sometimes start fine idle no problem but when I drive away it will stall. (Other times it wouldn't )I have to crank it several times and it will fire over and be fine. It will run no problem then all of a sudden hic-cup and get loud throwing a code P0251 .( Injection Pump Cam system) The truck still has power but it's almost like it's not getting fuel to all the cylinders.

My diesel mechanic says I need a new IP. I just want to make sure before I buy one. When I installed the PMD I put some dielectric grease in the connections . Could this be a culprit? Or maybe a bad wire harness??

see if your injection pump has a green or blue tag screwed on the cover, if it has one that should mean its a rebuilt one. If there isn't one then it could very well be the original pump and at 250k its worn out.

 

[97duallydiesel]

see if your injection pump has a green or blue tag screwed on the cover, if it has one that should mean its a rebuilt one. If there isn't one then it could very well be the original pump and at 250k its worn out.

I believe it's a rebuilt one. but I'll check tomm. Do you think the Dielectric has anything to do with the problem or a inferior cable??

 

[guybb3]

I checked the voltage to the LP with a volt meter when I turned the key on and it was reading 12. volts. I ran a new ground wire also, this was a problem before.

Did you check while it was pumping to make sure the voltage didn't fall off? Code 0251 is common with fuel supply or contamination problems. Have you checked your tank sock? From what I've read from your previous posts, you have a fuel delivery problem for sure.

 

[97duallydiesel]

Did you check while it was pumping to make sure the voltage didn't fall off? Code 0251 is common with fuel supply or contamination problems. Have you checked your tank sock? From what I've read from your previous posts, you have a fuel delivery problem for sure.

I have done numerous checks .. I dropped tank and checked fuel sock ( perfect) the Sending unit was replaced 3months ago along with lines and I just replaced the LP for the 3rd time. The FM is new along with filter.
I did check voltage when it was pumping and it was fine.

Another code does display tho : P0231 Fuel Pump Secondary circuit Low

What do you think ? This is driving me crazy and broke :mad2:

 

[NVW]

Try cleaning the grease out, as it is not conducive to electron transfer.

 

[97duallydiesel]

Try cleaning the grease out, as it is not conducive to electron transfer.

Leo, I tried the best I can ..I'll really try and dig it out when I get a chance.. Do you think I should say F*** it and by a Cable from PMDcable instead . atleast I know his stuff is good. Might be a worth while $38 investment??

 

[buddy]

If up to this point you havent checked the pressure on the LP you need to learn this check fast. It has been recommended only about 100 times since youve started the threads about stalling, hard starts, codes, etc...

Read this sticky about 10 times, then ask questions if you have any
http://www.thetruckstop.us/forum/showthread.php?t=6872&highlight=Lift+Pump+test

 

[bison]

Buddy i'm 150% with you on the fuel press check

Steve, clean that grease out now,it throws havoc with the electronics.

Its prob been suggested before,but replace the IP retun line with clear tubing permanently ,so you can check for air bubbles at any time.

 

[guybb3]

replace the IP retun line with clear tubing permanently ,so you can check for air bubbles at any time.

Nice suggestion for all of us.

 

[fonecop1]

Nice suggestion for all of us.

What kind of tubing can be used for this? Also how long of a piece do you need and it goes from where to where? A picture of one that has been done would be good. Thanks guys, I too think this is a good diagnostic tool just like a fuel pressure gauge.

 

[Brooklyn Tow]

Dump a qt of 30W non detergent oil in the fuel along with Power Service or Standyne fuel additive.....it's been known to clear a few IP codes in the past.