Help! hovers around 90 psi at idle! I cant boost at all because it goes extremely lean...

At idle afr's around 14.5 so thats normal but god the fp is 90psi!!!

Could it be the afr going bad? fuel pump going bad?

I have the AAM fuel return system

440cc injectors

walbro 255

greddy tt kit

when unplugging the vaccum from afr there is really no change in pressure.

could that much pressure actually cause my lean condition under boost???

im totally out of ideas here

 

Have you tried adjusting the FPR?

While I am sure that the diaphragm in the aeromotive can handle 90psi it wasn't intended for it like a Kinsler.

 

Yea i have tried but you can take the bolt completely off and it does nothing

 

the gauge is messed up..

 

Have you checked for kinks in your return line?

 

Audible...thats possible but how often does a gauge like that go out?

no kinks in the lines.

I still understand why im so lean tho...you would think with that much pressure id have to much fuel.

 

I would have to agree with Audible that your gauge may be bad if you are running lean which would seem like not enough fuel pressure.

 

I'll see if i can swap regulators and see what happens.

 

If your FP is that high, assuming you are using a Walbro then it may not be able to flow enough fuel for your setup:

@ 40psi - 60gph ~720bhp
@ 90psi - 37gph ~444bhp

 

kinsler

 

Kinsler=$$$

We use one on our Porsche 928 to control the 95psi system pressure!

 

sweet....ever play with hilborn?under 2k!

 

check to make sure your fuel pressure gauge isn;t grounding outon something. I had that happen on my old gauge. When I would accelerate hard, the engine would rock over and the end of the fuel pressure sensor would ground out on the chassis. the result was that it would give me a false pressure reading. My gauge would show the fuel pressure skyrocketing upwards of 90 psi.

now, the lean isssue; I don't know what that is. could be a pump issue, or a tuning issue. Firstly, figure out your fuel pressure issue.