flashing check engine light

So the other day I started my 91' 318ic and started driving and all was fine until I tried to hammer down on the pedal in second gear. It started to stutter and almost jump as if it were getting spurts of power. Soon after the check engine light came on but the weird thing is it doesn't stay on. If I give it gas it goes off but quickly comes back on and at a constant speed it flashes on and off at random times. Also, when I come to a complete stop, the rpms jump up real high and then after maybe a minute of being real high they dip way low and the car almost stalls and then it idles fine from then on. Here's the real thing that has me confused, if I let the car idle to warm up from a cold start it doesn't do the crazy rpm thing but the check engine light still flashes. Any ideas from anyone?

I think it means you're seriously damaging either the engine or the cat or even both...check if all connections are secure/tight in the bay. Seems like some sort of fuel connector or ignition wire.

Originally Posted by E60black

I think it means you're seriously damaging either the engine or the cat or even both...check if all connections are secure/tight in the bay. Seems like some sort of fuel connector or ignition wire.

That's very vague but I'll take a peek tomorrow and make sure all plugs are secured tightly. Although I was leaning more towards a sensor, because after it has time to warm up it runs fine, the check engine light just flashes

stomp test it, see what it says and go from there

Originally Posted by fcsteve

stomp test it, see what it says and go from there

+1

Do this before your next move.

Checks as above plus fuel rail pressure and leaks. Check fuel pump flow rate. Sounds a bit like fuel starvation at top end bringing on light via O2 sensor.

Originally Posted by fcsteve

stomp test it, see what it says and go from there

That was my first thought but didn't think it would work because it doesnt stay on. I'll give it a shot tomorrow

Well the stomp code was 1223 which it coolant temp sensor, which was what i had originally thought it was but wasn't sure. Never removed a coolant temp sensor before, what am I in for?

Originally Posted by Krumchev2

Well the stomp code was 1223 which it coolant temp sensor, which was what i had originally thought it was but wasn't sure. Never removed a coolant temp sensor before, what am I in for?

A treacherous, frustrating, and ultimately horrid walk in the park. No seriously though, it's insanely easy, just look at your thermostat housing and it's staring you right in the face, begging to be removed.

get those injectors rig cleaned and the ICV cleaned as well.