WHY IDLE IS STAYING TO HIGH RPMS AT 2000 IN PARK...

  • Tiny
  • mrsdavenport
  • 2004 Chevrolet Monte Carlo

Why idle is staying to high, rpm's at 2000, in park, in drive with no acceleration 1500 and at 50 mph 1500-2000. Wehave checked for vac. Leaks, fuses, throt. Body cleaned. Iac and o2 sensor checked. No check engine light. What else might be the problem?

Do you
have the same problem?
Yes
No
Monday, February 4th, 2013 AT 10:42 PM

7 Replies

  • Tiny
  • JDL
  • Expert
  • 16,289 posts

Block of the mouth of throttle-body, any effect on the idle? That should kill the engine. If no effect on idle, you definitely have false air getting in there from somewhere.

The throttle valve is closing?

I always check for codes, I don't care if the lite is on or not. I've had inactive codes point me in the right direction.

Was this
answer
helpful?
Yes
No
Monday, February 4th, 2013 AT 10:58 PM
  • Tiny
  • mrsdavenport
  • Member

We had it put on a computer, its not sending any codes. We changed iac, tps and used a vac. Gauge to check for leaks. We cleaned the throttle body. Tried to reset, by disconnecting the battery. Nothing we have done has helped or fixed the problem. So any further suggestions as to what is causing the problem, will be recieved with much gratitude!

Was this
answer
helpful?
Yes
No
Monday, February 25th, 2013 AT 4:47 PM
  • Tiny
  • JDL
  • Expert
  • 16,289 posts

Did you try blocking off the mouth of throttle body to see if it effected idle? Humor me.

Was this
answer
helpful?
Yes
No
Monday, February 25th, 2013 AT 6:29 PM
  • Tiny
  • mrsdavenport
  • Member

We did block the throttle body, it died, right away. We dont know what else could be causing the problem. Thank you for your help.

Was this
answer
helpful?
Yes
No
Wednesday, February 27th, 2013 AT 3:25 PM
  • Tiny
  • JDL
  • Expert
  • 16,289 posts

Some possibilities. Inspect.
High resistance in an iac valve control circuit.
The correct pcv valve, properly installed and proper operation of pcv valve.
Proper operation and installation of all air intake components. Check the maf sensor, where applicable.
A tampered throttle stop screw, where applicable.
Damaged throttle plate--throttle shaft--throttle linkage--cruise control.
Skewed high TP sensor/ circuit issue.
Excessive deposits in the iac passage or iac pintle.
Excessive deposts in throttle bore or on throttle plate.
Vacuum leaks.
A condition that the iac valve can not overcome.

I know you had no codes, but, there is a high idle speed code listed for your vehicle, even though the code didnt set. The above possibilities were listed for that code. I realize you have already checked some of those issues.
If you have a scanner that will show live engine data or have a friend that has a scanner that will show live engine data, now would be a good time to use it.

Was this
answer
helpful?
Yes
No
Wednesday, February 27th, 2013 AT 4:41 PM
  • Tiny
  • mrsdavenport
  • Member

Thank you so much. Thanks to your list, we now have hope again, we will look into the items you listed and have it put on a computer again. I will let you know how it goes! Bless you for your help

Was this
answer
helpful?
Yes
No
Wednesday, February 27th, 2013 AT 7:55 PM
  • Tiny
  • JDL
  • Expert
  • 16,289 posts

No problem. Let us know what you find.

Was this
answer
helpful?
Yes
No
Wednesday, February 27th, 2013 AT 8:42 PM

Please login or register to post a reply.

Similar Questions