MarkMelicia

Hello members,

I decided to replace my iac sensor because the idle has been staying up after it's warm at about 1500 rpm when I try to come to a stop as well as in park. I received the new part this afternoon but it seems to be faulty out of the box. It's idle up at around 2000 and staying there. Anything I could be missing? Just want to make sure before sending back

Thanks

BlueRidgeMark

1. You are assuming that your problem was a bad IAC.
2. Because of assumption #1, you are assuming that the replacement is also bad.
3. These assumptions prevent you from troubleshooting to find out what the cause really is.
4. It might be a bad IAC, and you might have gotten a faulty one.
5. It might be something else.
6. You won't know until you do some troubleshooting.
7. Swapping parts is not troubleshooting.

XJ_will

LOL I this same thing happened to me today, replaced IAC high idle put old one back in and it went down to about 1000-1100.

MarkMelicia

I'm assuming the part is faulty because the old part still idles semi normal but a bit high, while the new part causes the rpms to shoot up seemingly not regulating at all. Is that reasonable? What do u suggest?

MarkMelicia

Any luck with your scenario?!

DFlintstone

Your year is none of my business. But. You know the parts stores will check your codes free? Mark has a good point in my opinion. A vacuum leak will cause high idle. You might search that...and check your lines. When you search high idle, see if anyone mentions the TPS....

Radi

Yeah, remove the IAC but leave the connector plugged in and start the engine. See if it's extending, trying to lower the idle.
Could be the IAC is OK but the control signal is lost.

DFlintstone

Thanks Radi, yet another supper tip. We should buy you a Jeep!

CCKen

Did you clean out the orifice in the TB where the IAC pintle seats? If not, it may have crud build up that's holding the pintle off its seat.

MarkMelicia

I did clean it out first and it seemed to correct the problem for about a 10 miles. It was idling and and shifting gears perfect. But the problem came back shortly there after. Leading me to believe the iac was faulty. I recently replaced the tps which corrected a erratic idle problem I was having. This all seemed to start after a windshield leak onto my steering wheel. I noticed after, that my air bag light was on leading me to believe perhaps my clock spring shorted out. But after I siliconed the windshield stopping the leak the airbag light went away. This lead me to believe that the clock spring dried out and was ok. My check engine light is always on because f
Or that minor evap leak code. But I don't have a code reader and haven't checked lately

MarkMelicia

Thanks will check

MarkMelicia

My thought is that windshield leak shorted out the clock spring which in turn shorted out the tps and iac. I replaced one and am now thinking I should replace the other. Would that make sense?

RideNH19

I have replaced the IAC in a few XJs before. First if you bought a cheaper brand like Duralast etc.. the part could be faulty right from the box as i have experienced this many times with autozone parts. Also When installing a new IAC do NOT touch or turn the "plunger" the new IAC needs to be adjusted and the system needs to relearn the proper idle speed, thats why it could be reving so high. simple drive around for 5-10 mins at 40mph and the system will relearn itself.

sycoglitch

Hey OP, i stopped reading halfway through. What brand IAC did you get

MarkMelicia

Wouldn't I have trouble coming to a stop given the 2000 rpm? It's a standard brand part and is the exact part I'm replacing.