Possible IAC valve replacement?

TEX

MEMBER
2001 HYUNDAI ELANTRA
120,000 MILES

Engine revving high. When I disconnect the IAC valve, engine stops idling high but it is still rough. When I put the IAC back, it revs up high again. Already checked for vacuum leaks and didn't find any. It wasn't sticking, but I cleaned it anyways. I had 1 TPS code - P0121. I also checked the value and everything is in spec on TPS. Checked throttle.
How do I bench test the IAC valve? Could this be the problem? How would I check the values between the terminals on the IAC?

7 Replies

SATURNTECH9

MECHANIC
30,869 POSTS

So when you cleaned the iac did you remove it?Also does the tps code come right back when you clear it?

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Friday, June 22nd, 2012 AT 6:01 AM

TEX

MEMBER
6 POSTS

I did the bench test on tps. All the values are in spec. Didn't clear the code as yet.

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Sunday, June 24th, 2012 AT 3:57 AM

TEX

MEMBER
6 POSTS

Thanks for your help. So it turned out to be an intermittent vacuum leak between the 3rd and 4th cylinder gasket. The gasket was broken and stuck. Map sensor needed replacing too because it had a high value resistance between the map sensor terminals (15 k-ohms) when a new one only had 3.0 ohms. Because of the faulty MAP sensor, I couldn't check for the vacuum leak properly. So I hope this helps anyone out there who may have same the problem I had. My care is working GREAT now, even better than before. Thanks again.

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Monday, June 25th, 2012 AT 8:58 PM

SATURNTECH9