The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Rix Racing
Please Support ExtremePSI

Engine goes very lean when stepping on throttle.

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Brad Bell

Proven Member
192
5
Aug 15, 2014
Levant, Maine
My turbo 420a GS has started having this problem where if the rpms are low and I step on the gas (idle, or cruising), the engine goes extremely lean for a second and the car hesitates bad, after the rpms get around 2k it smooths out. The most recent mod I made on my engine is larger injectors running at really low fuel pressure for it to idle. I'm thinking this is either bad spark plugs (been about a year sense I replaced them) or its my throttle position sensor.
Thanks guys.
 
What are you using to tune since you've add many mods? If I recall from your past posts you have not addressed a ECU tuning method & have been fighting issues with compounded bandaid solutions. Also I believe other turbo 420A members have advised the need to pony up & referenced Megasquirt. You are going to have to pay to play.
 
What are you using to tune since you've add many mods? If I recall from your past posts you have not addressed a ECU tuning method & have been fighting issues with compounded bandaid solutions. Also I believe other turbo 420A members have advised the need to pony up & referenced Megasquirt. You are going to have to pay to play.
Well I haven't had this problem before, even with the larger injectors, so I figured it wasn't an ecu problem. In general if an engine does this what I described above what are some possible causes?
 
If you have no mechanical issues this would be a tuning problem. This sound like a tuning problem to me. You're asking an ECU to compensate for driveabilty conditions which are outside the OEM's ability to compensate for & bandaids (nor piggybacks) will not get you there. Hopefully some turbo 420A guy with actual first hand experience will chime in with better more specific advise. I'm a 4g63 guy running a full standalone because the bandaids nor piggybacks could compensate enough for my driveability issues after I added all my mods.
 
If you have no mechanical issues this would be a tuning problem. This sound like a tuning problem to me. You're asking an ECU to compensate for driveabilty conditions which are outside the OEM's ability to compensate for & bandaids (nor piggybacks) will not get you there. Hopefully some turbo 420A guy with actual first hand experience will chime in with better more specific advise. I'm a 4g63 guy running a full standalone because the bandaids nor piggybacks could compensate enough for my driveability issues after I added all my mods.
well you beat me to the exact reply i was typing out LOL
 
I forgot to add "Good Luck" for OP. @Brad Bell. "Good Luck"
Thank you Mello, I understand a standalone system like MS is the way to go, I'm planning on getting one next summer. Just trying to push the stock ecu to it's limits with my piggypack mods. I know there are some expert 420a turbo guru's out there, just hard to come by these days being the 4g63 is so popular.
 
Thank you Mello, I understand a standalone system like MS is the way to go, I'm planning on getting one next summer. Just trying to push the stock ecu to it's limits with my piggypack mods. I know there are some expert 420a turbo guru's out there, just hard to come by these days being the 4g63 is so popular.

You have a bigger turbo, bigger injectors, bigger fuel pump, and cooler air than stock (FMIC). You needed a MS a while ago. Not sure what piggybacks you are using, but I doubt it is right.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top