Turbo Question
 

I have a P5, with a custom turbo kit I have built on it. It uses a T28 turbo with a FPR (12:1) and an inline pump for safety. My problem is my car is running lean or at least it's lean for a turbo setup. On a wide band O2 meter I am getting 14.5 - 14.8 which is good for N/A, but not so good for boost. Does anyone else out there have a turbo kit and if they do have you measured your a/f? what numbers are you getting? My readings are consistant anywhere from 2 psi to 6 psi.

I have used a cartech and a vortec one (both are 10:1 or 12:1). My idle pressure is up to 40 because I used an inline pump. We did some testing, if I clamp off the return line and boost it, the fuel pressue actaully drops down from like 100 psi to 80 psi, if left unclamped I get around 80-90 psi depending on boost. It seems like the ECU is somehow controlling voltage to the fuel pump, something that I know happens in a Supra. We are still testing, but it seems that it does not work well with a Rising Rate regulator. We are currently testing the setup with a Greddy E-Manage to control fuel and see if that will help. We are trying to keep costs down on this setup because it will be made into a Kit for his shop after.

Check Valves

Done, I put in the check valves from the other night when I read a post hear earlier about it. Still no go. The A/F just will not go lower than 14.5. Hopefully I will have better luck tonite when I try the Greddy E-Manage.

squashy
 

I had the same problem the A/F meter would go all the way lean almost fade out it was so lean when I was at .01 PSI of boost and at WOT the ECU would cut all fuel and it felt like you hit a brick wall, classic fuel cut. Problem is the MAP sensor seeing the boost and cutting fuel. The Hondas have MAP sensor devise (Jackson Racing) that take care of this but not us its just the right combination of check valves and raising the fuel level with out the ECU seeing it. It took me a week of trying different things with the check valves before I found the right combination along with a fuel pressure regulator (Vortec 12:1 FMU). Remember to take the neg. battery cable off to reset the ECU before you try each new change. I would forget sometimes and get pissed that what I did made no difference then I remember the battery cable, reset the ECU and BAM I'd see the changes I was looking for. I'm running 6psi on the street at the track I run 8psi with three check valves two before the MAP solenoid and one between the solenoid and the MAP sensor. I had a tuff time with vacuum controlled stuff too. I had to find a good vacuum source for the boost control device to control the waste gate actuator. Depending on what vacuum source I used is how well the boost controller worked same with BOV.
Good luck!
Oh I have a Gen3 1.6L with manual trans. running a T25 with IC from a 2nd gen Eclipse