Incognito

Somebody please help me out.

I'm working on a turbo LS/VTEC with 8.5 to 1 compression right now, running a T3/T04 custom turbo setup. The car would boost in 1st and 2nd gear, then die out in 3rd. I am running a stock '95 GSR ECU on this setup, with no knock sensor. Does that affect anything (limp mode or anything?) The only check engine light code I get is for the knock sensor. We checked the fuel pressure and it was at 80psi. Not sure if my FMU is dead or something. Not sure what brand it is, but it's silver, about the size of the unit that comes in a Drag kit, and has 2 nipples on the top, 1 has a bleeder screw thing on it. Seems like after we set the fuel pressure, it doesn't always hold, because after we rev the car, it sometimes changes. The car seems to run best with the fuel pressure around 63psi at idle. Is that wrong? With 63psi at idle and the bleeder screw all the way opened, it will boost sometimes (wastegate set at 9psi), but breaks up and pops.

Please help me out. Thanks.

By thw way, right now I am running stock '95 GSR injectors and a Walbro 255gph intake fuel pump.

Giuseppe

sounds like a cartech unit to me,
http://www.cartech.net/fmu2020.html

but i know nothing about tuning them
i'm in the process of gaining knowledge too!!!

HTH

Incognito

My FPR or FMU thing looks somewhat like that one, but it's a little more squared, and it's rough, not polished like the one in the pic. Probably an older one. Somebody please help me out.

speedworks

you definetly need the knock sensor hooked up.sounds like a cartech,had a new
one and it would not work properly. switched to vortec and solved my problem

Evil DOHC

Your FMU is definetly busted. May I suggest lowering the pressure to around 60 psi with the hose off at base pressure (at idle). Then borrow or buy another fmu. With stock injectors u might want to use a 12:1 disk on the vortech or any other brand u buy. The reason the car is poping is because it is getting flooded with fuel. U can try to take the fmu apart and see if the rubber inside either busted or something is stuck open. Personally I would buy another FMU. I guarantee that is your problem. The car won't go anywhere if fuel is just being dumped and not burned.
On a 9 psi spring u will run over 100 psi of pressure at wot. If the FMU is functioning properly. 60 at idle plus 9psix12pounds of pressure per psi of boost=108. So around 168 pounds of pressure at full throttle.
EVIL