When I start my car it idles up and down, down to a point it almost dies. This started happening all of a sudden out of no where. I changed the coolant temperature sensor, tps, pickup coil, ignition module, coil pack. And none of that helped the IAC is some what new I just don’t remember when I changed it. I don’t want to keep buying parts I don’t need because it’s getting expensive. I’m posting a video of my car doing it. If someone had this problem and fixed it please let me know what you did... please I want a response from someone that had the same issue and fixed it.

 

Surging issues with tbi is common. Could be a few different things. You can test for each one. Check your injector spray pattern. You might have a leaky injector or sticking injector. Your fuel pressure regulator might need to be rebuilt. How old is your fuel pump? Last time you changed the fuel filter? Check your egr valve. On my 92 rs I had a long time ago the surging was from 1 sticky injector and a failing fuel pump. Check these area and report back. Also do a search for tbi surging.

 

I was in the process of rebuilding tbi it self, I got a little hot in the garage. But that’s what I was trying next. I try the others as well.

Thanks.

 

Connect a scan tool, investigate the data stream.

Verify fuel pressure. Verify all the "tune up" stuff is in good condition--ignition, fuel delivery, compression, exhaust.