I have a 96 civic hatch with an si harness, 94 gsr swap with obd2 distributer, alternator, and harness on the engine, and running a p28 obd1 ecu with a conversion harness. i just got the car running and everything, and it runs ok, but there are some issues.

1. when the car starts, the idle jumps up into the 2500's, and then will drop below 500, and when i give it gas, it lags and acts like its going to stall.

2. after driving for more than about 10 mins, the idle spikes down, then comes back up and idles at 1600

3. my temperature gauge does not read at all when it gets hotter, and stays right on the 2nd notch of the guage.

4. vtec does not hit

I had the engine in an eg hatch, so i know it runs and everything works but the check engine light is on and i have not checked the codes (mostly because i dont know how with the setup i have since its both, obd1 and 2) but if anyone can help me with any of these problems it would be greatly greatly appriciated.

 

id like to know how you got an obd2b harness to plug into an obd2a car

 

and is this a stock P28 or does it have a basemap on it?

 

It is a stock p28 that is chipped to redline at 8600. thats all i know about it (bought it as it was)

 

and a 99-00 civic si harness should not be able to plug in, inside the car

 

Did you repin the wires at the ECU connectors for the IACV? I had my swap done for about 2 months after I figured out what I had to do. that's prolly why you're CEL is on. Search on here about it, I found a few good threads when I had to do mine. It's pretty simple to, took me 5 mins.

 

alright cool i will try that thanks!

 

to read codes, just jump the service connector like you would on any other honda