ok, so I've checked my fuel pressure at idle and WOT. My pressure at idle is about 53 psi, and at WOT it is about 80-90 psi. I know that is normal. I have also checked my vaccuum lines and I've checked my fuel pump and my FMU and everything is hooked up right. I also have to tell you that my car ran for the first year I had turbo on (97 GS). But recently in the last few weeks/month it has been running lean at about 6 psi of boost and up. I used to run 7 and 8 lbs no problem. Now I am down to 4 and 5 psi. My question is since I've checked everything fuel related the only thing left is the injectors. Is that what my problem could be. I ran fuel injector cleaner through it twice over the last couple of months but the second time didn't seem like it made a difference. Could it be the injectors and if so should I just move up to 310 cc or just buy used stock injectors? Thanks in advance.

could be your injectors. What FPR are you using? I don't feel like doing the calcs right now but 80-90 PSI seems kinda low for stock injectors. Can you go higher? WHaat fuel pump do you have. But for the love of god if you buy new injectors get some 310's your car will be much happier:thumbsup

I CANNOT adjust the pressure because I am running just the Vortech FMU, and the fuel pump, Walbro 255lph. I think I am for sure going to get the 310's. You think 80-90 psi is a little low? I thought that was normal. Let me know. Thanks for the help man.

This is a quote from corbins site. http://www.2gnt.com/www/corbin/example.html

Turbo kit manufacturer recommends the following fuel pressures
50 psi at idle
60 psi at 0 psi boost
90 psi at 6 psi boost
110 psi at 9 psi boost
Approximate engine horsepower is 220 at 6 psi and 275 at 9 psi

You said you were running 80-90 fuel PSI...was that at 6 boost psi? If so that should be about right. But if you were trying to run 8 to 9 on that...that's lean. I'll get some better numbers tomarrow..I have an excel spread sheet at work that helps me alot.

I made an excel spreadsheet for fuel calculations too. I followed everything to-the-t and it still gives me too low of numbers. I gave up on fuel calculations. Tune by data instead. And get an adjustable FPR when you can.


1996 Eclipse RS / 5-Speed / Aerogear Body / Coated in Magnetic Red Metallic rev.2 / T3 Turbo Intercooled @ 8 psi / More at http://home.insightbb.com/~mgalyan/
Mark Galyan - Indianapolis, Indiana

Your fuel pressures at WOT seem low, as suggested. The HRC manual states you should run about 100-110 psi at 8-9 lbs of boost. I'd say that's your problem, but it is odd that it started all the sudden while you were running fine before.

Originally posted by cseithel
ok, so I've checked my fuel pressure at idle and WOT. My pressure at idle is about 53 psi, and at WOT it is about 80-90 psi. I know that is normal. I have also checked my vaccuum lines and I've checked my fuel pump and my FMU and everything is hooked up right. I also have to tell you that my car ran for the first year I had turbo on (97 GS). But recently in the last few weeks/month it has been running lean at about 6 psi of boost and up. I used to run 7 and 8 lbs no problem. Now I am down to 4 and 5 psi. My question is since I've checked everything fuel related the only thing left is the injectors. Is that what my problem could be. I ran fuel injector cleaner through it twice over the last couple of months but the second time didn't seem like it made a difference. Could it be the injectors and if so should I just move up to 310 cc or just buy used stock injectors? Thanks in advance.

Heres another stupid question . What is " WOT" & what cc are the stock injectors.

WOT os Wide Open Throttle. pedal to the metal. and i believe the stock injectors are somewhere in the neighborhood of 190cc, i could be off though. been a LONG time since i had stock injectors. if your running lean all of a sudden, id check two things. your O2 sensor, and change out your fuel filter. also make sure all your connections on the FMU are still snug, and havent worked themselves loose over time.

1999 Black C5
1997 Silver RS
Wiseco 8.8:1 Pistons(back to low compression!)
Eagle Rods
T3/T4 Turbo
Custom FMIC
Greddy Exhaust
390's
Most current 1/8th mile time: 8.3@90mph 2.015 60'(Nitto Drag radials, i suck)

What kind of fuel cut defensor (FCD) are you using with your MAP sensor? the "missing link" or a electronic one like HRC kits come with?

The stock injectors are actually 235 cc I believe. I got rid of the black box and got a missing link a long time ago. I checked the connections on the FMU a week ago or so. They were good, I also checked the connections on the fuel pump too (walbro 255 lph) and they were good also. I think I will have to replace the fuel filter, that is one thing I haven't changed on my car yet since I got it (oops) 4 years ago. Hopefully it lies somewhere in there with that or the injectors.