Assuming fuel issue, please help!
 

1993 FD, street port, single S366 BW, 1600cc secondary, KG rails, stock FPR on secondary, 2row FMIC, 3.5 turbo back. Was built 1000 miles ago at that time was put on 10psi and basic tune for break in. After break in took it back for tune and at 15psi looked to be leaning out, so he wired the fuel pump straight to the battery. Helped but didn’t fix it totally, he suggested a new pump as I was unsure which pump was in the car. I took the car home and installed a stealth340, also did the wire mod to direct feed the pump. Ever since that install the car idles different, runs different and when I put it in high boost at 15psi it stumbles and bogs way down when trying to accelerate...

Any suggestions?

If there was something very wrong with the original pump it very possible the tune needs to be completely redone. You probably have more fuel under all conditions.

My thought is that I am now overwhelming the factory FPR and need to get an adjustable FPR and retune. My thought is just way rich, I have a wideband I need to install, that should help shed some light on the issue as well I would think.

You can test this with a fuel pressure gauge.

this is a frightening setup.

you have a turbo that can make 68 pounds of air at 14.7 psi boost (512 rwhp) and 77 pounds of air max (580 hp)

http://imagizer.imageshack.us/v2/xq90/674/O0CeTJ.jpg


one pressure ratio (14.7 psi boost) should require 6.8 pounds per minute of fuel (gasoline) to be able to tune to 10.0 AFR and at max boost you need 7.7 pounds per minute.

5467 CC/Min injectors at 14.7

6193 CC/Inj at max boost.

you have two 1680 injectors as secondaries so to properly supply fuel at 14.7 psi boost you need at minimum 1053 primary injectors.... (two of them)

at max boost you need two 1416 primaries.

you say you won't be running max boost? what happens when your wastegate sticks shut?

and who would put this together w a stock FPR?

what ECU?

i don't see mention of an AI system?

from what you say it does appear you are running rich and ATM that is a very good thing. you have a large turbo and it will be important for you to make sure you have proper support systems.

Fuel Rule number one is to have enough fuel to support 10.0 AFR at max turbo output.

there are a number of other rules...

good luck,

howard

Howard,

I am using Bosch 1680cc Secondary with 550cc Primary, PFC management, no more than 15 pounds of boost at high boost and 10 at low. You are talking way above my level here, but the car setup was built by Ray at PFS. I am in the process now of putting together what I need to buy to install an Aeromotive A1000-6 FPR.