Question96 Eclipse, 2.0, GS-T, Manual
I am currently running a stock 96 Eclipse GS-T except for the following: EVO 3 16g turbo (with ported manifold), and an ETS front mount intercooler. After installing the mentioned parts and starting the car again (it had been sitting for a couple months), WITHOUT plugging up the MAFS, the car ran poorly. It was running VERY rich and sputtered from 2000-3000 rpms. BUT, the turbo did spool up building the appropiate amount of pressure. I then re-installed the MAFS/airfilter. After plugging the MAFS back up the car ran just like it normally did, no sputter, nothing. BUT, no turbo. The turbo does not spool up at all from what I can tell when the MAFS is plugged in.
After troubleshooting I have come to this conclusion. The turbo spools up great with the MAFS unplugged (but the car runs poorly). and when it is plugged, the turbo will no spool up (but the car runs properly).
Does the MAFS need to be replaced?
AnswerStuart,
The MAFS can easily be tested if you have a service manual and cheap voltmeter. If it doesn't test within the specs in the manual, you'll need to replace it. Since the turbo is just a mechanical component what turns based upon exhaust flow, it should be spooling up somewhat. But with all the extra air entering the engine with with larger turbo, bigger FMIC, and ported manifold, that can cause your car to run lean. Your ECU recognizes all this air entering from the MAFS. So it's probably retarding the timing and making the car run smooth but slower to prevent detention. With the MAFS unplugged, the ECU is blind to the amount of air entering the engine. You may feel the turbo kick in and recognize boost levels from your boost gauge (hopefully you have an aftermarket one), but this leaves your engine defenseless to possible detention. You can try replacing your fuel filter and testing your fuel pressure regulator to be sure it's operating properly.
Good luck!
