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  1. TBerkey

    I need a replacement P7100 pump for my 1995 12 valve, manual transmission. Doe anyone have any feed back on Pensacola Diesel? Can anyone suggest a mechanic in North Florida in the St Augustine/ Palatka area? After owning the truck for 28 years I can not believe what I did, I put $90 dollars worth of gasoline in the truck. I stopped as soon as I could get off the road but the damage was already done. I had to drop the tank to drain and the fuel puck up was very rusty so had to order a replacement, I also replaced the lift pump because i \was losing top end power before. By the time I got to flush Diesel through the system it as about 2 week so I think that was the final killer of the P-pump. i wish I would have rigged up some way to flush diesel the the injector pump as soon as I got it home. Any suggestion will be appreciated. I had just spent about $8,000 to restore the truck and hate to give up on it now but at 73 years old I do not feel i can do the work my self, i drop everything I pick up at least once.
     
    TBerkey , Dec 23, 2023
    #1
  2. Ozymandias TDR MEMBER

    Really? Your pump was destroyed by Gasoline? That's almost impossible by the design of the pump as it is lubed by engine oil. I've never heard of something like that before.
    Back then we always used gasoline throughout the winter to keep the diesel from geling.
     
    Ozymandias , Dec 23, 2023
    #2
    BigPapa likes this.
  3. BigPapa TDR MEMBER

    I’m with Ozy, hard to believe gasoline took it out. Did you run the full tank through it? I’ve never been a fan or heard of Pensacola Diesel. I’ll see what I can dig up on a mechanic in your area.
     
    BigPapa , Dec 23, 2023
    #3
  4. TBerkey

    I only ran it for 2 min at the most it was barely running by then. it was 2 week or so until i flushed clean diesel through it. I have fuel up to the P-Pump but only get a small amount thru to the injectors, I get some dampness when bleed injector but no pressure. I tried pinching off the return line by the firewall to see if pressure would build, but did not seem to make a difference. Could the gasoline have damaged the injector and maybe they at stuck open and not letting the pressure build?
     
    TBerkey , Dec 23, 2023
    #4
  5. TBerkey

    It was almost a full tank of gasoline it was about 6 to 1 gas.
     
    TBerkey , Dec 23, 2023
    #5
  6. BigPapa TDR MEMBER

    I don’t see how, it’s all metal. Two minutes of straight gas shouldn’t damage the pump, either. If you’ve had the fuel system apart from the IP to the tank, I’d say you still have air or something’s loose and sucking air. Have you tied the shut off lever up to eliminate the shut off solenoid as the problem?
     
    BigPapa , Dec 23, 2023
    #6
    Ozymandias likes this.
  7. Ozymandias TDR MEMBER

    Don't pinch the return line, that's where the air wants to go.
    Loosen the Injector lines at the injectors HALF A TURN and crank the engine until pure diesel sprays out in a strong spray, then tighten them up one after another.
    It will fire up and run.

    Injectors won't get damage by gasoline, no problems there.

    I sure you just need to thoroughly bleed it from residue air and all is fine.
     
    Ozymandias , Dec 23, 2023
    #7
  8. GAmes TDR MEMBER

    Pensacola diesel has a bad reputation over on the Cummins Forum.

    I don't see how gasoline can harm a P7100 either, but it is only the lower part that is lubed by engine oil. The plungers and delivery valves are lubed by fuel.

    Did you replace the fuel filter? Are you able to refill the filter with the primer button and get solid fuel through the bleeder bolt on the filter housing? Do you have a fuel pressure gauge?
     
    GAmes , Dec 23, 2023
    #8
  9. TBerkey

    The shut off seems to be moving the full amount when turon;n key to start and run. I have pumped a gallon or more fuel by hand with the lift pump to bleeder bolt and to inlet to P-pump. I even hand pumped until I got a little fuel at cracked open furl injector. when i crank it it is still just a little moisture but not the pressure I am expecting to see. A few time after hand pumping a hundred or more time i did get a little sputter like trying to start but only for a few seconds.
     
    TBerkey , Dec 23, 2023
    #9
  10. BigPapa TDR MEMBER

    Are you working by yourself? Get someone to crank it and keep it running the first few seconds and it will smooth out. One of you cranking, the other wrenching on the injector line. The line has to be tight to run and loose to eject the air. You can’t do it by yourself.
     
    BigPapa , Dec 23, 2023
    #10
    TBerkey likes this.
  11. TBerkey

    I replaced the fuel filter right away. I filled the filter before putting it on and can prime fuel to the bleeder bolt and to the input banjobolt on P-pump bolt on P-pump. I had bought a pressure gauge just before my mistake but did not put it on until after my mistake. It bounces around when I try to start but I think it loses voltage when I turn key to start. I have not been able to get any steady pressure reading but not sure how the 3 in 1 gauge work. I have not found a single mechanic the can or will take a pressure reading for me. When I hand prime i can feel the pressure build on the button then it seems to lose that pressure. I have replaced to lift pump twice already, I got one on Amazon then replaced it with another from Geno's.
     
    TBerkey , Dec 23, 2023
    #11
  12. TBerkey

    I have been a one man show. I will try to get some help, what you say makes sense.
     
    TBerkey , Dec 23, 2023
    #12
  13. Ozymandias TDR MEMBER

    As a last resort after doing a good manual bleed you can use some starting fluid, the higher rpm through the running engine bleeds the pump and line much better then a starter can.

    Disconnect the grid heater first.
     
    Ozymandias , Dec 23, 2023
    #13
  14. BigPapa TDR MEMBER

    Make sure to do this if using ether.
     
    BigPapa , Dec 23, 2023
    #14
    Ozymandias likes this.
  15. GAmes TDR MEMBER

    I've bled the injector lines working by myself. First I stroked the primer button until I could hear the OFV squeal. Cracked each of the lines at the injectors and cranked the engine a few times until one or more ejected fuel, then tightened them and hit the starter again. I don't know if it makes any difference but the pedal was pushed to the carpet. It started running and I had to quickly shut the key off to keep diesel fuel from leaking all over the place from the fittings that were still cracked.
     
    GAmes , Dec 23, 2023
    #15
    Ozymandias likes this.
  16. BigPapa TDR MEMBER

    BigPapa , Dec 24, 2023
    #16
  17. Signal73

    Pensacola burned me way back on a p-pump, wouldn’t recommend them. I ordered a 215 and they sent me an old bus pump with mismatched DV’s. They did take it back but that interaction has stuck in my mind.
     
    Signal73 , Dec 24, 2023
    #17
    BigPapa likes this.
  18. GAmes TDR MEMBER

    The first time I re[laced my lift pump I didn't fully tighten the elbow fitting and it sucked air. It needed one more turn which I just knew was going to break something, but it didn't. The second time I needed a new pump the fiber gasket on the inlet line was bad. This gasket is not shown on Cummins Quickserve. PN 3923194 Once again air was being sucked in and the engine wouldn't start. The bad gasket is pictured in Joe G's fuel system writeup. (Joe was also a member of this forum a long time ago.) Joe G's fuel system writeup | Cummins Diesel Forum (cumminsforum.com)
     
    GAmes , Dec 24, 2023
    #18
    BigPapa and Ozymandias like this.
  19. mpsmdsr TDR MEMBER

    uto and Truck Repair has been in St Augustine for many years.
     
    mpsmdsr , Jan 12, 2024
    #19
  20. mpsmdsr TDR MEMBER

    Melvin's Auto and Truck Repair
     
    mpsmdsr , Jan 12, 2024
    #20
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