fueling problems

[SeattleSy#1255]

i am going to verify what i think my problem is with knock and that i may have a bum FPR or FP. i'm going to hook up a fp gauge and see it it rises 1ps per lb. of boost...past base fp that is.

i expect to see it drop or waiving all around when i do this.

my question is:

is there a way to really ID the problem as either the AFPR or FP? Are there signs of one that may be more prevelant?

i've already concluded its likely not the injecters or injecter. i'm trying to avoid having to buy new parts when not needed.

can't figure out what happened....i have an Accufab and a Walbro, suppose to be solid products

 

[SY2455]

Re: fueling problems

When you have a press gage hook up. Engine at a Idle. Write down your press. Turn the engine off & see what your press is now, it should stay the same as your Idle press. If it does not hold press you are leaking thru.

 

[SeattleSy#1255]

Re: fueling problems

interesting, ok i'll try that as well. does that point toward the FPR then or elsewhere in the fuel lines?

 

[TYRODD]

Re: fueling problems

interesting, ok i'll try that as well. does that point toward the FPR then or elsewhere in the fuel lines?

If your injectors are leaking it will do the same

.

 

[SY2455]

Re: fueling problems

If your injectors are leaking it will do the same

.

Like TYRODD said, but usually it will be the AFPR because a seal fail inside & after you turn the engine off you might find raw gas on a spark plug if that injector is bad.

 

[Chromy]

Re: fueling problems

How hard is it to change injectors? I've never done it before and eager to learn.

Garth

 

[timgt]

Re: fueling problems

I had a similar problem and checked everywhere before realizing that the leak was coming from inside the tank. It ended up being the little rubber piece that replaces the resonater thing (cant remember the name) when installing a walbro fuel pump. The clamps were not tight enough and pressure bled off and I would even lose FP when building boost instead of gaining FP.

If you do fully lose pressure when you cut the truck off like I was, then get under the truck and clamp the fuel line (rubber piece near center of the truck) and see if you still lose pressure when cutting the truck off. If you dont then your leak is in the tank. Good luck.

 

[SeattleSy#1255]

Re: fueling problems

ok i tried this and i went from 50 to 48, so not much...am i suppose to leave this alone for awile or check it right away...the above results were right away. Is 2 psi significant...i'm waiting on my 4 AN line so i can check it while in boost. Should be here this week.

to answer the qeustions, changing injecters is easy...takes 15 min or so. i personally remove the upper intake, but it can be done without doing so. its just much easier to get the fuel rail out. Just got to make sure you know where things plug into, espically your vacuum hoses. The first time you do it, it'll take you awaile. After 5 times like me, its a 10-15 min. job. Revmove upper IC, TB, Intake and you are there.

 

[SeattleSy#1255]

Re: fueling problems

bump....anyone?