I have a 99 bonneville that Has new Wires Plugs ICM and a new Coil for 1 and 4 but still have a misfires on 1 and 4 triple checked the order without a scope how do I test the ECM to find if its bad?

Side Note I am Getting spark off the coils and to the plugs so should I be looking towards injectors?

ok so hooked up to the computer watching Misfire count 1 and 4 went crazy for a while. I fluttered the throttle and it misfire count stopped after about 20 seconds i heard a change in the motor and stopped the 3 and 6 started counting up. I read Lean when Idle and rich when fluttering the throttle not even enough to increase RPMS just steady tap on the cable throttle angle stays at steady 1%.

Anyone have ideas?
thanks for your time

Are the misfire counts the same for 1 and 4?

You can take your ICM module into autozone and they can kinda test it, but most of the time when ICM'* fail, its when they are hot.

Your fuel trims won't change much while you are in open loop.

Based on what you changed so far, I would check fuel pressure. The fuel pump might be failing.

Fuel Pressure is running between 45 and 52 PSi.

Yes it was 1 and 4 then those stopped and went to 3 and 6.

Once I unplug the TPS all misfires stop but I do still get a super lean on the trims idle sits around 23 STF an 20 LTF


The ICM is new and with it changing from 1-4 to 3-6 i don't think its bad.