I have a 99 Eclipse GS, It’s been turbo charged by Star stage II turbo Kit. I never had any problems my car running lean, before when I stepped on the gas my air/fuel ratio gauge read rich, but now its reading lean and towards the middle, barley any rich. The way I noticed this, my check engine light came on, and the error code was "car running lean". I have changed the fuel filter; I always use chevron 91 octane and same problem. Can some one tell me what I can to fix this problem? Thanks in Advance. Tony K.

Check your fuel pressure regulator. Make sure you are getting the proper amount of fuel at boost. Make sure all the vacuum lines are attached. I guess youre using the Hahn kit? The cartech FMU is pretty crappy and gives out pretty easy. Are you running lean all the time, or only while under boost? Try to datalog your Short Term Fuel trims and your Long Term Fuel trims if you can.

NeoVB
2005 Subaru Impreza 2.5RS
1997 Mitsubishi Eclipse GS TURBO
1995 Mitsubishi Galant ES DOHC TURBO
1991 Eagle Talon TSI AWD

Hi, Its running lean when iam idling and when on gas. Before when I was on the gaz, the light led would be on the 1 led green running rich, but not any more. I have the Star turbo kit from Wyatt. Is the fuel regulator the the round blue vortex thing by the fuel filter or the one thats on top of the fuel filter?

Im not 100% familiar with the Star Kit, but I believe the FMU is the vortech thing youre talking about, and the the thing on top of the fuel filter is your stock FPR. What year is your car? Doublecheck to make sure that all your fuel components arent screwed up. Check your fuel pump, lines, injectors, etc. You really should get a Fuel Pressure Gauge and see what fuel pressures your running at idle, 0 psi, and at full boost. This will definately help you diagnose the problem. Try running some fuel injector cleaner through your system.

You might want to think about upgrading to a Vortech SFMU, its a very reliable unit.

NeoVB
2005 Subaru Impreza 2.5RS
1997 Mitsubishi Eclipse GS TURBO
1995 Mitsubishi Galant ES DOHC TURBO
1991 Eagle Talon TSI AWD

how many miles you got on your car? also how rich were you running? could also be your o2 sensor.. mine front (1st) one went out within 2 months of being turbo.. maybe because i was little or alot richy. also could be your fuel injectors ? might want to run some fuel injector cleaning in..
good luck
Michael
99gs (broken) Motor being built now
HRC Stage 2 8-Injector Setup
Fully Built by July 25,2003 hehe
2GNT Member #32

I did run some fuel injector cleaners and didnt help, I changed the o2 sensor and replaced it with Bosch o2 sensor 2 weeks ago. My car is the 99 GS 10th special edition. I need to have my car running rich so I can get my car smoged, I cant now because the check engine light is on and its giving error code "running lean". Getting my fuel injectors cleaned by a pro, would that help? Thanks for your feed back guys, I will have pics up soon.

oh ya, i forgot to add, my car has 48,000 miles.