I've had this issue for at least a year and a half now, and it happened a few months after ZZP dyno tuned my car. The car is an 07 Saturn Ion Redline, which has a supercharged 2.0 LSJ in it, my mods are 2.9 billetflow sc pulley, adjustable belt tensioner, 60# injectors, 2-step colder plugs, K&N CAI and filter, and an LS4 throttle body.
When ZZP tuned the car, it had the stock TB, and I had the surge before I threw on the LS4, however it was slight, maybe surging ~100 rpm tops, I threw on the LS4 thinking it may have been an issue with the stock tb and decided I might as well upgrade it, I changed the Area Scaler for it to 4000, and the surge was only made worse due to the heightened response of the new tb.
Due to the sensitivity of the LS4, at idle the rpm drops as low as 200 and shoots up as high as 1500, and USUALLY goes into this cycle until it either by some grace of god levels off and actually idles normally, or it just dies. However, if it does stall out, 9 times out of 10 when I start it back up it idles just fine, until I give it some gas then let off for it to idle, and it does this all over again.
When it idles my timing advance also jumps around like crazy, even when it's idling steady. Going anywhere from -10 up to 35ish and back.
I'm relatively new to tuning, so I can't figure this one out on my own, and it's getting to the point where it's causing other problems. Does anyone have any advice for me? Thanks in advance.
I didn't ask, but good point, I took it down. And yeah, throttle scalar was adjusted, however it had the surge before I swapped out the tb, so that's somewhat irrelevant.
Ok. You need to work the surge out before you go to the bigger throttlebody. Try setting the ecu up for verifying injector settings. Some times the 60 data gets thrown in and the multipliers don't get verified or injectors get tuned with the multipliers active.