[NeilM]

So I recently bought a 92 Suzuki sidekick with a 1.6 16v and I’m having a very high idle problem (2,000-2,500rpm) and in some cases a surging up and down idle. At first when I bought the rig it was a TPS issue would not run right with it plugged in (code 22) and when I fixed that shortly after I got a fluctuating idle issue like I am now. So I replace the IAC valve and everything ran great…for a day or so and back to where I am now. The only code I get now is 45 which is the “idle switch circuit” which would be IAC? TPS has its on codes 21&22 but what’s weird is when I give it throttle the light goes away and comes back after it maintains a idle for a second. I can hear the IAC clicking on when the keys turned and staying wide open and when I clamp the suction hose to IAC I can get it to idle perfectly. It almost seems like the ecu isn’t pulsing the IAC ground only holding it wide open. I tried 3 different new IAC valves sense they had lifetime warranties and kept swapping them out but nothing. Confusing why the first IAC valve worked for a day or so before problem came back. Now I’m stumped if maybe I need a OEM IAC valve or is it wiring. Any input is well appreciated, thanks!

-Neil

 

[xkaes]

Welcome to the Forum. There are lots of knowledgeable people here to help you out.

While you're waiting tell us more about the model you have -- miles driven, how it's been used & maintained, engine, tranny, body, last tune-up, etc.

Given the age, I'd suggest you check out the ECU for burned/leaking parts. Do you have any repair records?

It sounds like you have a service manual, correct?

 

[aquanaut20]

If you are experiencing the same issue, why are you swapping out the unit instead of confirming the circuit first..

Before getting fixed on the AIC, fix the TPS error first as that has a bearing on the idle..

 

[NeilM]

FIXED. Started wiggling plugs until finding chaffed wires needing repaired. The main harness that runs under the intake manifold had two wires directly under the manifold hidden with exposed copper that were grounding out on each other causing the IAC to stay fully grounded causing the high idle.

 

[aquanaut20]

Actually that has been a common reported situation.. Good work...

 

[fordem]

FIXED. Started wiggling plugs until finding chaffed wires needing repaired. The main harness that runs under the intake manifold had two wires directly under the manifold hidden with exposed copper that were grounding out on each other causing the IAC to stay fully grounded causing the high idle.

The term "grounding out" would mean that the wires are being incorrectly connected to ground (in this case the intake manifold which is connected to chassis ground/battery negative). If the wires are incorrectly being connected to each other, than that is a short circuit.

 

[NeilM]

The term "grounding out" would mean that the wires are being incorrectly connected to ground (in this case the intake manifold which is connected to chassis ground/battery negative). If the wires are incorrectly being connected to each other, than that is a short circuit.

I was assuming 1 of the two wires exposed within the harness was a ground it’s self running direct to the IAC causing it to never pulse only remain a open circuit. If it was a short I’d assume a fuse would pop. But thanks for the explanation.