ive got a 2001 cavalier 2.2 with a t3 turbo and full 2.5" intake and exhaust. no matter what i do im getting lean and rich spikes during tps changes. the car spikes really lean when you push the throttle and spikes really rich when you let off the throttle. the condition gets better when i unhook the fpr so its constant pressure all the time. no matter how much or little fuel i program in the tables the car has really bad hesitation when a fpr is hooked up to the vacuum line. ive tried the stock and aftermarket adjustable fpr. no matter what i do using an fpr the car has so much hesitation that you fly forwards in your seat then fly backwards when the motor quits hesitating. my wideband shows 20+ a/f no matter what i do when the fpr is hooked up, and ive literally tried 100 reflashes with incremental values because i assumed i might be flooding the motor. nothing....still huge lean spike with an fpr. using pe for enrichment off idle and unhooking the vacuum to the fpr seems to solve the driveability problem but you still see lean spikes and hesitation when you slam the pedal to the floor. it does this under any rpm, any map condition. am i at a dead end here with the factory pcm and need to seek out an aftermarket solution that offers accel enrichment or is there something im overlooking? ive messed with ipw vs map with no success, tried over-fueling the motor for accel conditions only, and no matter what i get a bad hesitation. even reflashing back to the factory alpha-n program has the same effect. no matter what i have a hesitation upon quick map changes i cant get rid of. anybody else run across this or happen to have advice? i can be at 5lbs boost(full boost) in pe mode with throttle at 40 percent and get a hesitation when i move the pedal quickly. am i past the capabilities of the stock pcm?
"...and then God said let the 2.2's have potential. Thats when hell broke loose..."
One you are not past the limits of the stock ECU. I just tuned a 2.4 twin charged set-up to 266whp with 15psi. I would need to look at a file from the car to say more. Have you tuned the idle VE table. What injectors, what injector constant?
FU Tuning
lemme know what you wanna see on the datalog and ill do one tomorrow and post my most current tune /w and /wo fpr working /w the datalogs
"...and then God said let the 2.2's have potential. Thats when hell broke loose..."
bro, hit me up this week. I don't go back to school until this sunday and can lend a hand in person.
Have you checked your fuel psi?
P&P Tuning
420.5whp / 359.8wtq
