ignition control module question

[Dustindell]

1996 grand prix se 3100 engine. I'm having issues with the car reaching cruising speeds. Car seems to bog down quite a bit like it's not getting enough spark. This only happens when the car is in closed loop mode. When I unplug the O2 sensor to make the car run in open loop mode it run flawlessly.

Does the ignition control module work differently when the car is in closed loop mode?

 

[Sven the Sexman]

No but the O2 sensor certainly does.

 

[SnowTh1ef]

unplug your maf and see if it fixes it. sounds like a bad maf to me.

 

[Dustindell]

New mass air flow and I just replaced the oxygen sensor. This car has me stumped.

 

[Dustindell]

An update of what I have found. I took the ICM out and had it tested, came back good. But I still decided to go to the junkyard and grab one. Got one off a running car and got a knock sensor as well put them both on the car, still bogs down during acceleration. So I unhooked the knock sensor to put it back in open loop and pull the air filter out. Drive the car around and of course it drives perfect like it did before in open loop. Shut it down and let it cool for 15 minutes then hook the knock sensor back up but keep the air filter out. Car is now in closed loop, drive it around and it runs perfect now. Got home cleaned the air filter really good put it back in and the car is good to go.

I'm not sure if the computer had to learn the new parts or what but it's fixed and that's all I care about.