have a h22a4 swapped 92 civic with p28 Chipped ECU..
The car runs fine but has a MIL, I got code 7. I replaced the TPS and have my .45 at idle and 4.5 WOT, but now the car when you start it the check engine light goes on again after about 5 seconds at the same time the RPMs drop then go back up, drop again after about 4 seconds and drops when you give it light gas, If i unplug the TPS sensor it's fine..

Any idea what this can be? I tried scanning the ECU again and got nothing.

 

Do you have a test ECU? I don't trust a chipped one when stuff like this happens.

 

FITV?

 

no this is the only ECU, car is fine when it's warmed up so the IAC is clean ( + i cleaned it) just jumps when i start it every couple seconds and MIL goes on.

 

I cleaned the FITV, Have not reset the ECU or battery since I put the new TPS on and calibrated it.

The car runs ok the problem now is still a check engine light after it has been running
I have to bleed the cooling system and reset the ECU

what the car is doing is when you start it (you know how it revs when it's cold to say 2000rpm) well it does that , then drops to 900 for a second and goes back to 2000..
also when you cruise and let off the gas it drops to 800 or so and comes back up like it did hen you started it...
What can possibly cause this?

 

when going to burp the cooling system, the thermostat wouldn't open up to further let the air out, the entire ride home after giving up the 30 minute idle the lower hose was still cold so i would assume it is stuck shut, any suggestion? would this throw a MIL?