My car: 92 civic with second gen. b16, I swap the engine a month ago.
ECU: P28 with mugen program
Problems: car idle at 450-550 rpm
I already tried:
1. the IACV is good because I tested.
2. there is power source from the plug to the IACV
3. When I unplug the connector from the IACV there are no cel code and engine light comes on. The car just die when unplug the connector form the IACV while it's running. When I plug back the car idles at 450-550 rpm.
I think the ECU is the problems. What do you guys think?
BTW, I already did a few search.





[Modified by porsche997, 6:08 AM 3/20/2003]

 

ttt

 

ok well if you pulled the plug on the IAC and the engine speed did drop or stall, you need to adjust the base idle speed. That is the only solution.

1- start the engine. Hold at 3000 rpm with no load until fan comes on.
2-connect a tachometer
3- disconnect the 2p connectors from the IAC and the EVAP purge control solenoid valve.
4- If the engine stalls restart the engine with the accelerator slightly depressed. Stablize the rpm at 1000 then slowly release the pedal until the engine idles.
5- Check idling in the no-load conidions: headlights, blower fan, rear defogger, radiator fan, and air conditioner are not operating.

After adjusting idle speed, check ignition timing.

6-turn ignition off
7-reconnect the connector to iac and evap, then reset the ecu.
8-restart and idle the engine with no-load conditions for one minute then check idle speed.

 

To adjust idle speed do this:

1. Start the engine and hold at 3,000 rpm with no load untill the fan comes on
2. Disconnect the 2pin connector from the IAC valve
3. If the engine stalls restart the engine with the accelerator slightly depressed. Stablize the rpm at 1000 then slowly release the pedal until the engine idles
4. The idle speed should be 500-600 rpm
5. If the idle speed is not within spec, adjust the screw located on the throttle body
6. Once idle is within specs, reconnect the 2pin connector to the IAC valve
7. Remove the Back up radio fuse for 10 seconds, which is a 7.5 amp fuse located in the engine bay fuse box

This is the proper way to do it. Once your done, get in the car and take it for a spin.

 

Thanks INTEKRAGSR & PANDA EK. You guys nails it. It idles fine now. Wow, this is something new. I didn't know this is the way to adjust the idle. Thanks again guys.

 

glad you fixed your idle problem.
Now I have to fix mine somehow

 

**** I have the same prob. how do u test the IACV though? I have the same symptoms my car idles at 500rpms and when I unplug the IACV the car stalls. I don't know if I should replace my IACV but I dont want to until I know that thats the prob. Is there anyway to test it?

 

Just try doing what I posted before...... if it doesnt work let me know. Maybe I can drive over and help you out.

 

Sup Panda tried that and every time i unplugg the IAC it shuts off. I keep it on 1k rpms for a while and when I let it go it dies out still, if I take out the Idle screw completely off of the Throttle Body then it will idle at 200-300rpms but as soon as I put the screw back in the car stalls again. I checked for vacuum leaks and when I spray carb cleaner in the throttle body then the idle drops. I checked all hoses for vacuum leaks, the IM gasket and the Throttle Body Gasket, no luck.

 

civicrtype you got an IM

 

please keep me posted on your solution and attempts to fix. I would like to know also.

 

Same from me