Bolo

In chip mode,1st gear is ok,even on hard acceleration. But on 2nd gear or higher, the car starts to experience fast pulsing jerking and surges when rpm goes passed 3000.....enough to make the CEL warning to flash. After a while,the CEL dissapears...but will return if I try to Accelerate again on 2nd gear or Higher.

I got worried and switch back to stockmode for now.....To my surprise,everythings fine in stockmode, even when trying to accelerate hard.

Can anyone tell me what might be happening and whats causing the hesitating/jerking/surging and CEL to flash while accelerating ? (In Chip mode)

clean.

which injectors are you running?

Bolo

Unfortunately...APR's big injectors (not the TT's)

diagnosticator1

The reason it is happening in chipped mode and not stock mode, is because in chipped mode, the cylinder pressure is very much higher at the ignition point. The high pressure requires higher coil secondary voltage to force a spark to jump the spark plug gap, higher voltage than the coil pack secondary is able to achieve. It sparks OK, in stock mode because the cylinder pressure is a lot lower at the ignition point.

LINEa_roja_de_S

when I switched to stock mode,it was my coil pack

Stefano Scalia

From what I've seen, that's your problem I believe. Doesn't APR have a new version of their injector

Bolo

Dang!..all my Coilpacks are the latest revised 'L",And 2 still failed lastyear.Whats causing this???

diagnosticator1

pressure. (Boost pressure significantly effects the dynamic compression ratio/pressure)

diagnosticator1

The higher secondary voltage generated by the coil pack when chipped is to much stain on the parts, and the properties for insulation resistance etc deteriorate, then fail. There is an "N" version cp available now also. Hopefully, that version will put this trouble down for good.
Coilpacks fail less frequently in stock engines.

Bolo

I did try Accelerating aggressively at all gears in Stockmode...And everything works fine.