Hi All, I am new to the group and in search of answers concerning this topic. I have a 6.6, LBZ. Previous engine had over 1,000,000 miles as per the odometer and had constant P0087 code as soon as I began hauling trailer up any incline and of course, lost half power of engine. Engine had catastrophic failure so I was able to procure a "new" 87,000 mile engine. Had engine installed, replaced turbo, and only transferred bolt on accessories. New engine came with h/p fuel pump and all sensors. Engine cranked and runs great, except... I am still getting the P0087 code, Low Fuel Rail Pressure. I have had all, and I mean, all fuel lines replaced, sending unit (complete) from fuel tank replaced, and I just spent 430.00 on a new "Air Dog" 150 lift pump, and it still goes into limp mode. Seems like my mechanic keeps going in circles. I had the ECM checked at a dealership a while back and they said it had all the latest updates and seemed to be fine. At this point, I am lost and I think so is my mechanic. Has anyone else had to deal with this and if so, what was the outcome, short of getting a new truck, which I cannot afford to do at this time.
Low Fuel Rail Pressure
- Thread starter averdinsr1
- Start date
I really thought that when I replaced the entire engine that I would be throwing out this problem and would crank up and run like the wind. What are the chances that the new engine came with the same problems as the old one. Different sensors (on the engine), injectors, pumps.
My mechanic is going back to the engine and running all the vacuum tests and pressure tests that he ran on the old engine. In my mind, it seems like the problem was left on the truck and has just carried on to the new engine. what part on the truck would cause this. Remember, all new fuel lines, supply and return, new pump, new complete guts in tank.
A scanner of some sort (V2, Tech2, Snap-on, CTS2) will be able to tell you these #s. While I was at it I would check balance rates on the injectors. Is the fuel filter new? I could try and throw possible problems out there but they would just be a guess at this point.
Fuel filter is new. The mechanic does have a scanner and he knows those numbers. I don't know if he has tested these on the new engine to date. Today he was checking the vacuum. I thought the pump would overcome any shortcoming in vacuum.
hes not a mechanic, hes a parts repalcer and all they do is drain your wallet.
Anthony (gmduramax) has nailed most of the points and things to check
you need to get that truck to a competent shop and quit wasting your money on this guy.
Anthony (gmduramax) has nailed most of the points and things to check
you need to get that truck to a competent shop and quit wasting your money on this guy.
Is the FPRV the plug at the rear of the fuel rail on the driver side? I had him replace that with a plug (saw on a video) on the old engine and it didn't help. He said he was going to transfer it to the new engine earlier today when I spoke with him.
LBZ's are famous for low rail pressure when towing when the injectors are wore out and returning too much fuel. It can be the only symptom you get when they are like this. I did not see where you mentioned if they had ever been changed? It also can be a wore out cp3 too.
Rail pressure should be checked actual vs desired fuel pressure relief valve checked balance rates and the flow return rate should be checked pump would be commanded noted kpa or psi in tech 2 numbers and readings will help to better determine and properly diag said concern whats the reading on the fuel filter in of mercury? All this will help
I did look it up and now I know what it is. I just can't believe that the pump on the old million mile engine, and the one that came on the new 89,000 mile engine have the same problem and show up the same way. I know its possible but not plausible. Same thing for injectors. The only fuel related thing that was transferred was the fuel filter housing/pump. My mechanic said that he did a check on that part and found no leakage, although I would think that still could be the culprit.