bad vp?

[johnstontruckin]

I would start with checking easy stuff, you need to rule out a clogged fuel filter or a bad lift pump. Get a clean 2-liter soda bottle and maneuver it under the hood where you can put the drain hose from the filter canister in it without kinking it. Then bump the starter (don't start it) then open the drain valve within 10 seconds. You should get a good rush of fuel into the container, should get it half full in maybe 10-15 seconds. If not then your filter is really clogged but more likely the lift pump is dead or dying.

Well i got a bottle and it almost filled it with fuel after i bumped the starter so i dont think it has a clogged filter or weak lift pump! I am going to try another vp soon! I will report back

 

[meuris71]

Whats the fuel psi?

 

[flatbedodge]

did you make sure to line the keyway up when installing the "new" vp

 

[johnstontruckin]

Well I got a fuel pressure gauge on it and when I bump the starter it runs for twenty seconds and carries 15psi. When I start the truck it quickly drops to zero. So just to make sure I hot wired the pump to run and It did the same thing. . . . So that tells me I need a new lift pump? But the odd thing is as I hot wired the lift pump to run it made the check engine light come on. It threw three codes and I used a cheap scanner to clear them and when I started the truck again the miss was gone? Any ideas why it would be gone all the sudden ? There were no codes at all initially . And it still would drop to zero fuel pressure but free rev to 2500 with no miss so I'm confused!

 

[johnstontruckin]

I bought a brand new fass lift pump and got it installed and I still have a miss. I havent put the gauge on it yet but I will tomorrow. I am so frustrated with this thing I cant see straight. There are no leaks that I can see. Does this sound like a vp? Im going to put some more fuel in and let it run for a little while.

 

[RyanH]

If it had 15 psi but dropped to 0 with engine running then it was a clogged filter, remember water drain is pre filter. Probly contaminated injector tubes and/or injectors/lines. Crack inj lines with engine running one at a time if one or more doesnt knock engine down when cracked then thats the one.