Kaliona

I've read posts about disconnecting the IACV before turning the idle adjustment screw to adjust the idle. I have a couple problems though. Being a noob with Civics and fuel injection, I have no idea where the IACV is and I can't find the idle adjustment screw. Does anyone have any good pics showing where these things are on a 1990 Civic? Or a link with good instructions and pics on how to adjust the idle?

The idle is not wandering. It's just drops a little low when the car warms up.

Any help would be appreciated.
Thanks

jddwls

MPFI or DPFI, pretty big difference in idle adjustment. . .

Kaliona

The top of the intake has a cover that reads "Dual Point PGM-FI Programmed Fuel Injection". Does that help?

OneBadTurboCRV

Not really... just locations of things.

The idle screw is on the passenger side of the throttle body under the "black toilet bowl". The IACV is on the driver side of the throttle body and is the piece that has coolant lines going to it and is laying flat on the intake manifold (next to the TPS). You should adjust the idle with the IACV unplugged. Then technically you should jump the 2-pin connector and make sure your ignition timing didn't change, after you have plugged the IACV back in and cleared the code of courses.

jddwls

what i meant was locations, sorry for the delay, hard to get this stuff at work tonight. . \

https://honda-tech.com/forums/showth...dle+adjustment

Kaliona

Just want to make sure I'm disconnecting the IACV. Attached is a pic I took. Is it number 1 or number 2?

Thanks

sticky,s-ef

# 1 is the TPS #2 is the one u whant to disconnect

check this mite help http://images.google.com/imgres?imgu...a%3DN%26um%3D1

88DXCRX

Idle adjusment screw:


Electronic air control valve:


#2 is is "TANDEM VALVE CONTROL SOLENOID VALVE"...

Kaliona

Ok, now that I know where the IACV is, I also found this info on the steps to adjust the idle. Sound right to you guys?

"If your idle is stable but either too high or low then you need to adjust it with the idle screw, but don't just turn the screw blindly! The correct way to do it is by letting your car warm up then, while the engine is running, disconnect the IACV (Idle Air Control Valve) electrical plug behind the intake manifold, and adjust the idle screw to 800rpm. After doing that turn your car off, reconnect the IACV plug, then disconnect the battery for a couple of minutes to reset the ECU because you will have a CEL, doing this will get rid of that CEL. Connect the battery and your Idle should be at its normal range - 800 +/- 50 rpm"

I got this info from this thread:
https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/how-fix-your-idleing-woes-fitv-iacv-2153910/

dacrxguy

what is posted above is correct but you can also disconnect the 15a hazard fuse in the passenger side shock tower for 15 seconds instead of disconnecting your battery(i do this since i dont like loosing my radio presets and you have to readjust the clock).

smichka

is there a way to adjust the TANDEM VALVE CONTROL SOLENOID VALVE

cause my car just idles perfectly once is warm

and works like **** when it's cold

smichka

wait wait

on DPFI,IACV is on the driver side of the intake manifold

so u should disconect IACV ot that TANDEM VALVE CONTROL SOLENOID VALVE behind the TB ?

lmumoz16

Hi the thick tube to the right of your hand in the top picture is ripped in my 1990 honda civic dx hatchback what exactly is that?

smitty2020

I had a problem of high idle. I cleaned the IAVC and it didn't work, still high idle. I took apart the vacuum dashpot and their was 2 pin holes. So I used liquid tape to fill the holes and now it idles correctly. so if you have high idle check the vacuum dashpot for holes before you do anything else.