So I just got my Evo out of the shop after an e85 conversion. I'm working with a tuner on an etune right now. Issue is the car keeps getting super lean at high boost. I don't know what else to do. I'm ready to part this damn thing out. Mods are below. Tomorrow I'm gonna try a new O2 sensor in my wideband. If that doesn't work I'm gonna try a new FPR. If that doesn't work I don't know what the hell to do.

Walboro 455lph e85 pump
-6 an fuel feed lines
FIC fuel rail
ID2000cc injectors
Aeromotive FPR
HTA3582r
RNR ramhorn 35r kit
TBE
ported intake and tB
Kelford 272s
Etc
Etc

Please help
I have logs

 

Is using the stock fuel return line going to be a problem?

 

What kind if fuel hanger are you using stock? What kind of fuel pressure do you have at the rail at idle? Are you running E85 now?

 

I'm on e85. Pressure at the rail is around 55-60psi at idle.

 

I'm using the stock hangar

 

Fuel pump relay could be taking a dump.

 

How much boost. With that high of base pressure you could be openinig the relief valve in the fuel pump

 

30psi

 

Because of my stock return line my pressure is that high at idle. I was wondering if getting a bigger return line would help lower my base pressure and solve my problem

 

The siphon on the hanger and the return line causes the base pressure to be high. I drilled the siphon and added a 6an return line. If you have a stock FPR I wouldn't do both. Contact Tedb on here if you decide to drill the siphon. He talked me through it.

 

Are you running a rewire?

 

That puts you at over 90 psi at the pump with pressure drop through the lines. Im betting the relief is cracking open and you are not building more pressure

 

I bought the rewire kit from map and have it to my shop to install when they did the work. I'm going to take a look at it when I get back in town to make sure its wired correctly. I guess my next step is to put a larger return line on so I can get the base pressure down and try that

 

Have you tried dropping boost to 20 psi to see if it still does it? Then work up a couple at a time

 

I'm trying that tomorrow. Not sure what its going to prove other than the point where it starts