IAC, idle to high.
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IAC, idle to high. My car has a P1509 code, and it idles at 2000ish on the stock tach, which is off slightly. But the idle is still a little high just from hearing the car. The car took 70 miles to throw this code, but no other codes thankfully! Lol. Does would using shoes method of resetting the IAC work? Or should I go ahead and replace it? Any other thinks to check that might have made it act funny?
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the IAC solenoid itself, or the wiring to it, could be bad or it just needs to be cleaned if it is sticking. Use throttle body cleaner on it and the cavity it is in. do not push/pull the printle (pointed end of it)
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Would replacing it be my best bet? I have 9 more days left to get it inspected... Parts stores want 100$ for a BWD brand. When online a DELCO brand is 88$... But I don't know if I can wait around for it to get here before my temporary ten day tag runs out...
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I did clean it. It seemed to have helped somewhat, the gauge shows 1800 but my tach is off so it's around 1100. Normal idle for a M6 I would think is slightly higher than an auto.(?) but if need be I will reset it. Cleaning it has helped so I'm sure resetting it will probably fix it.
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as shbox advises, also check for a vacuum leak. those cause high idle.the "L" shape vac hose right under throttle body could be cracked...as well as any other vacuum line on the engine,
at 1100 RPM emission testing may not pass if that is what you meant by "inspected".
at 1100 RPM emission testing may not pass if that is what you meant by "inspected".
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Inspection for me is visual, and plug in only. No sniffer test, Everything visual should pass, I have 4 new tires, new wiper blades etc... All the stuff they look for. New windshield blah blah blah, just can't pass cause when the light was off the IMs were reading "not ready" then the light came on shortly after for the IAC to high, so I cleared the code and drove another 70 miles and boom! It came on again, got it scanned, same code. IAC to high. So I'm glad it's just that one code but I cleaned, and reset the IAC and still nothing. I've checked for vacuum leaks and haven't found any so far. The "l" shaped thing is on the left side of the TB, under the one heater hose looking thing going to the valve cover??
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Every time you clear codes you need to have several drive cycles for the IM monitors to reset. PIA. I had my tuner make mine always read "ready" to get around that issue
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No, the "L" shape vac hose routes to DS manifold (PCV IIRC). It is centered on front of intake manifold under TB. It or any of the vac hoses and plastic or rubber elbows can crack and leak, especially if they are still original.
Every time you clear codes you need to have several drive cycles for the IM monitors to reset. PIA. I had my tuner make mine always read "ready" to get around that issue
Every time you clear codes you need to have several drive cycles for the IM monitors to reset. PIA. I had my tuner make mine always read "ready" to get around that issue
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....by making a "click" sound when your Dad was messing with it....did he push or pull on the end of it?
If so he killed it. Do NOT push or pull on it, just spray it off with cleaner...but your new one will be clean so just install it. Do th e"reset" procedure for IAC when motor warms up. Hopefully your high idle is just a faulty IAC.
By chance did you mess with the throttle body stop screw. The right answer is no. If yes meaning someone turned it to raise the idle for some reason that would need to be set back to stock position. There is a reason why a TB gasket actually covers the access port to that stop screw :-)
If so he killed it. Do NOT push or pull on it, just spray it off with cleaner...but your new one will be clean so just install it. Do th e"reset" procedure for IAC when motor warms up. Hopefully your high idle is just a faulty IAC.
By chance did you mess with the throttle body stop screw. The right answer is no. If yes meaning someone turned it to raise the idle for some reason that would need to be set back to stock position. There is a reason why a TB gasket actually covers the access port to that stop screw :-)
Last edited by BALLSS; May 18, 2016 at 05:16 PM.
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....by making a "click" sound when your Dad was messing with it....did he push or pull on the end of it?
If so he killed it. Do NOT push or pull on it, just spray it off with cleaner...but your new one will be clean so just install it. Do th e"reset" procedure for IAC when motor warms up. Hopefully your high idle is just a faulty IAC.
By chance did you mess with the throttle body stop screw. The right answer is no. If yes meaning someone turned it to raise the idle for some reason that would need to be set back to stock position. There is a reason why a TB gasket actually covers the access port to that stop screw :-)
If so he killed it. Do NOT push or pull on it, just spray it off with cleaner...but your new one will be clean so just install it. Do th e"reset" procedure for IAC when motor warms up. Hopefully your high idle is just a faulty IAC.
By chance did you mess with the throttle body stop screw. The right answer is no. If yes meaning someone turned it to raise the idle for some reason that would need to be set back to stock position. There is a reason why a TB gasket actually covers the access port to that stop screw :-)
but the new one will be here soon! I really hope that's it... I still haven't found a vacuum leak. Could a faulty 02 cause a high idle? Even though I haven't gotten an 02 code, just wandering. Thread Starter
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So the IAC got here today, I cleaned the TB and the cavity that the IAC goes into, to look like it was polished chrome. I spent a good 30 minutes on it, put the new one in. The idle bounced around a little and FINALLY adjusted and now it idles around 900ish... Good for a M6 car? I think yes! Way better than what it was.
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No aftermarket TB. And motor is stock internals, but does have some bolt ons. I got a tune by Solomon letting him know every little detail there was about my car. And by 900rpm I mean around 650. The tach is off a good amount. when I hit my 2 step or MSD box modules it's always way off on the tach than what the modules are rated for. It's idling and running sooo money right now.
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Interesting. My car sounds to be idling perfect, but like I said the tach is way off so there's no real way to tell exactly the idle unless I data log. But I no longer have a lap top so.. Oh well lol. It runs good though, thanks for the help Shoe!