I have an h22a in an eg hatch running off of a chipped p72, I just got the car and don't know much about how it was built (wiring) but it seems to be done at least halfway right. Today I started it up and the idle was at about 2300, then after about 5 min it started to drop to 1300 then go back to 2300 (sloping idle). I cleaned out the iac and still nothing. When I unplugg the iac it dops to 1300 and runs like its got a big ass cam, I got a buddy comin by to let me try out his iac that I know works fine. Any other tips???

 

Who knows what the tune is for, how well the tuning was done, etc. That could be a large part of the problem right there. Your IACV is probably working fine.

 

Well the "tune" is supposed to be an h22 basemap. The check engine light is on, but it has been on since I got it (a few days). But it just started doing this. Is there any other obd1 ecu I can use without any tuning? Just to verify its the ecu

 

Better idea: Find out what the CEL is. I'm not convinced it's the ECU. The tune is the first thing I suspect if you just got the car, but if you have a CEL then you have a clear indication that something isn't right.

There is a service check connector on the right side of the car under the dash, and if you jumper that then the MIL light (CEL light) will flash out the trouble codes. Google list of trouble codes, which will often have the procedure for jumping the connector, and all you'll need is a paper clip...

 

i had the same problem in my h22 and it was the tps sensor.

 

I had a friend tell me there is a good chance it is the tps. He told me with the tps unplugged it shouldnt have an up and down idle. I will check the codes in the morning and try with the tps unplugged, but I dnt wanna wake the neighbors right now..but I wouldn't think something went wrong with however it was tuned overnight. That's why I am leaning towards a sensor prob. Thanks for the help and please keep suggestions coming

 

update**, if I drive the car for about 10 min, it stops and runs fine. with the tps it just stays at 2800rpm, I was told if it was a tps prob it would most likely make the idle settle out when unplugged

 

Have you found out what the CEL is?

 

its more then likely your FITV, its attached to the bottom of your throttle body

 

ok another update***, i took teh ecu out to see if it was chipped as previous owner said it was. it is not chipped, its just an oem obd1 p72 ( i didnt even think an h22a would run on a stock p72). so I put the ecu back in, and started the car. car ran great, but still has cel. So i put a paper clip on the small 2 prong pklug that hangs down where the ecu is (to check cel), and when I turn the ignition on the light comes on with teh fuel pump, the goes out. its like the ecu clears any codes its throwing everytime you turn the car off. then it comes back on as soon as you start the car. I know I need to get the ecu chipped and a basemap put on it.