High Idle - Code 14 and 41

[Jayamashey]

B16 OBD1 in an '89 SI.

My idle is all over the place. With the IACV plugged in I get a high idle in the 3500 RPM range. With it unplugged it bounces badly (feels worse than the high idle) at 1700ish RPM.

I m getting codes 14 (IACV) and 41 (O2 Heater). I swaped the IACV from my D16 ('89 OBD0) and still getting the same issue. I have checked for vaccum leaks and have none.

Any suggestions?

 

[AHHVTEC]

make sure you dont have the wrong plug pluged in

 

[brian11to1]

have you tried cleaning the IACV? do you ahve the coolant lines hooked up right? is it low on coolant? is the thermostat opening?

 

[CRXSIR1]

high idle

This fixed my problem Honda-Tech.com: Surging Idle? How-To Tech Article...(56k beware) hope it helps you.

 

[Jayamashey]

The IACV worked fine on my stock engine. It was clean. And yes, the coolant lines are hooked up.

The engine is NOT low on coolant.

I assume the thermostat is opening since I have heat in the lines and heater. The engine temp sensor is working.

How else would I check the thermostat?

 

[reikoshea]

If you arent overheating, id say your thermostat is good. Maybe little bubbles in the coolant. Something to DEFINITELY get checked is the O2 sensor though.

If the O2 sensor is bad you will experience a funky idle even before the engine is warm. If you didnt change over the sensor for the new OBD then itll throw a code causing the problem youre describing.

 

[Jayamashey]

Its a new 4 wire O2 sensor. The wiring appears correct but its possible the 2 black wires are reversed since I don't know what they are for.

 

[reikoshea]

i really dont know. i suggest these things because i know what causes what. i dont have experience with 02 sensor conversion (since i deal mainly with accord and prelude chassis) but from what my buddies tell me during their swaps, the 02 sensor is something easily messed up.

 

[Jayamashey]

No overheating. Its a new 4 wire O2 so I don't know why I am geetting the code. Verified blue wire and white wire are connected correctly, but since there are 2 black wires its possible those 2 are swithced. I will rechekc that, but still shouldn't lead to extremely high rev's.

 

[reikoshea]

it might be reading your afr incorrectly leading to a high idle. thats the only reason i suggest it. if im thinking right, it shouldnt matter though. black usually means ground (unless the black is actually a black stripe).

but since your throwing a code for both iacv and o2 sensor, those are good places to start.

 

[brian11to1]

is the plug for the o2 stock or did you rewire it? there are two black ones one i think is a ground but the other is for the heater circuit. you can try reversing the wires and then clear the ECU.. if you still got the code, you can chip the ECU and disable the O2... i know crome has that option.

 

[Jayamashey]

I am going to try to swap the two black wire. The connector on the O2 is stock but the connector on my harness was wired by me.

As for the high idle i am goin gto try the suggestions above and look at the TPS.

 

[reikoshea]

i dont see the tps even being suggested .....

 

[Jayamashey]

Well, After checking everything it turned out to be the FITV. The screw came loose inside. The code 14 was being caused by the FITV not the IACV (even though code 14 is for the IACV). Once fixed the idle is great. Thanks to CRXSIR1