Possible IAC valve replacement?

2001 HYUNDAI ELANTRA
120,000 MILES
Avatar
TEX
  • MEMBER
  • 6 POSTS
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?
Jun 22, 2012 at 2:02 AM
Advertisement
Avatar
SATURNTECH9
  • CERTIFIED EXPERT
  • 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?
Jun 22, 2012 at 6:01 AM
Avatar
TEX
  • MEMBER
  • 6 POSTS
I did the bench test on tps. All the values are in spec. Didn't clear the code as yet.
Jun 22, 2012 at 10:56 PM
Advertisement
Avatar
SATURNTECH9
  • CERTIFIED EXPERT
  • 30,869 POSTS
Please clear the code and see if it comes right back?
Jun 23, 2012 at 3:32 AM
Avatar
TEX
  • MEMBER
  • 6 POSTS
Code came back. So I got a hold of a new IAC and checked the values with mine. The values are the same, which leads me to believe that the IAC is ok. I now feel that it may be the map sensor. How would I go about checking that? Thanks.
Jun 23, 2012 at 4:42 PM
Avatar
SATURNTECH9
  • CERTIFIED EXPERT
  • 30,869 POSTS
We need to find out why it keeps setting the tps code thats where i would start.Follow the directions i posted and let me know what you find.
Images (Click to enlarge)
Attached Media
Attached Media
Jun 24, 2012 at 3:57 AM
Avatar
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.
Jun 25, 2012 at 8:58 PM
Avatar
SATURNTECH9
  • CERTIFIED EXPERT
  • 30,869 POSTS
Your welcome glad to hear you got it fixed.
Jun 25, 2012 at 9:02 PM