I've got a 99 teg that I just dropped a stock 96 LS down in. And running the old p75 ecu that I used with the last motor.

Ok, here's the deal...

I go to start the car in the morning, immediately revs to 2800 rpm then slowly comes down to 2000. Once I drive around town the idle is usually at 1500 (which is still too high). Sometimes it will fludder from 2800 to 2500 for about 10 secs before dropping to 2000.

Now here's where it gets interesting.

Once it idles down to 1500, if I stop somewhere and shut the car off, come back out and start it to leave, the idle will be at 800 which is ideal.

Could this be an iacv? Or tps sensor or bad ecu? Or a timing issue??

Please help. It's driving me crazy!!

 

I would check your timing, and then next time you have a second, drive it around and get it warm, pop the hood, and unplug your idle air control valve. Set the idle to where you want it (usually it should be around 800) using the flat head screw, and then shut the car off, disconnect the battery for about 15 minutes, plug the IAC back in and reconnect the battery and drive. That should help the problem. Basicially you are setting the base idle of the engine with no idle air control valve and now that it is set, the IAC will be able to compensate for changes in the load of the engine like the AC or cooling fans turning on and putting more strain on the engine. If you have time when you are disconnecting the IAC you could remove the 2 12 MM bolts and check the little screen inside the port on the left and if it is plugged up with carbon you can get a can of brake cleaner with the little red straw on it and spray the ports until the carbon is gone. That will clean the valve so you will be able to eliminate a dirty IAC as one of the culprits.

Hope this helps,
Maddogg

 

It's helps a bunch!! Thank you. I'll try it first thing tomorrow

 

Where would I find this screw to adjust the idle?

 

It acts like a dirty FITV. But I was told 96+ manual integra don't have one. And I was also told NOT to mess with idle screw because that is what the ecu does. Is this true?

 

yes and no. the ecu controls idle through the iacv. that's why you disconnect it when adjusting idle.
follow the procedure for adjusting idle and see where that gets you

 

I was gonna say, have you adjusted your idle according to the Helms. Let car warm up till fan kicks on, remove plug from the IACV, adjust the idle, turn car off. Plug the IACV back in, disconnect the battery for 5 minutes, reconnect, start car back up.

 

Fixed it! My FITV needed adjusted. It was screwed out too far letting to much air in.

 

i thought you said it was a 96 manifold

 

a trick i use is to take off your intake and on the inside of your throttle body will be 2 holes... plug the top one with ur finger and if the idle goes back to normal its your idle control valve... if not then plug the bottom one and if that fixes it then its your fast idle valve

 

It is a 96(obd2). I read where some had it and some didn't. Kind of weird.

 

sorry, but that advice is absolutely inaccurate. the iacv part anyway

 

I believe only obd2's dont have FITV's because the idle is controlled by the IACV only. OBD1 and below need the FITV because the ecu isn't programed like obd2's.