Is rewiring a fuel pump necessary?

Mods;

RB turbo back
Ported wastegate
walbro fuel pump (255 high pressure - In mail, here in like 4 days)
Homebuilt FCD
A/F guage, bosst guage, volt guage (havent installed but I will hook it to fuel pump within a week)

1987 tII
142k original miles (Man, Im pushing it with these mods!)

Seems like the car is hitting 6psi at half throttle at 4k rpms. (Just started her up today after a long winter's nap, dont want to beat her up yet)

I also have an old intake kit which didnt sell with my acura. I may be able to set it up for the RX7, will I run into problems of boost creep?

 

It may benefit you since you are going to be able to run 10psi with just the RB exhuast if your turbo is in good shape. With an intake you can ad anywhere from 2 to 5psi depending what kind of intake you make. My 87 TII can go over 15psi by 4krpm!!! (my wastegate actuator wasn't working)

Also check your fuel pressure, because with that new fuel pump, it has a LOT more volume, and it goes through the same size pipe, so that equals higher pressure!

You will have to redo your idle, and adjust the idle rich/lean potentiometer cause it will increase your fuel pressure at idle. I have an SX fuel pressure regulator to help control the fuel pressure.

Watch your Air/Fuel and/or EGT to make sure you don't go lean. You should also check your timing if you are installing a FCD.

The computer can't retard timing much, so at double the stock boost level you won't be pulling the timing back enough, and with the inefficient intercooler the air gets hot and well, you don't want to detonate much with that many miles!! It all sorta goes together. Heat, spark timing, and boost level. The stock knock sensor is not the greatest......

The stock fuel pump gets only about 9volts dc until you get into boost, and then it bumps the voltage up to battery voltage....which should be about 13.5vdc or so.

Mine was not going to 12 vdc as it should, so I bypassed the system by wiring in some 10ga wire straight from the batt to a 12vdc relay (Bosch) so that it recieves battery voltage all the time. The relay is activated by the stock fuel pressure relay (same wires, just attatched to the new relay)

Other than that it works great. I can tell you how to do it in detail if you want. I finished mine about 6 months ago and have had no problems with it at all.
The Walbro is a good pump for your mods imho.
Hope all that helps!

Maybe someone like RETed will post and back that up

 

Isn't it always a good idea to rewire it, since it doesn't always get full voltage at WOT? That's what I heard, anyway.

 

i never rewired mine and the other night i hit 13psi. mods are on the sig. i read rich the whole run. dont bother....if your air/fuel gauge or egt tell you to then do it. otherwise dont. oh yeah that run i mentioned was at night with lights on, radio, radar detector all on. i advise you have a/f and egt gauges though!!

 

anyone got a link to a tutorial about this?

 

c/o Scott mac http://www.1300cc.com/howto/how2/rewire.htm

Sean

 

excellent - thanks scathcart

 

Good job. you woke my dead thread!

 

gorockrx
has giving one of the most informative resposes

This whole FCD thing
I never thought about the FCD and timing
Bingo!
I think I know why I blew the motor now