Idle control valve question

JimB911 · 01-21-2005, 10:06 AM

I have always had a fluctuating idle on my 84, so I thought I would troubleshoot it. I pulled the ICV off and everything appears to be loose and operating freely, but the resistance is a little off. I get 30 across the outer terminals and 15 across the center to outer. Bentley says it should be 40 and 20. Is this within tolerance?

JimB911 · 01-21-2005, 01:59 PM

Can anyone help me with this.
Thanks.

stlrj · 01-21-2005, 02:07 PM

Two things that make it fluctuate, mixture too rich or base idle speed set too high...take your pick.

-Joe

Tim Polzin · 01-21-2005, 02:08 PM

I doubt if the difference in resistance would make much difference.

There has been quite a bit written on Carrera idle problems. Some people have found setting the bypass to spec helps, other have had to change the mixture adjustment.

Probably the best place to start is setting the bypass adjustment to spec. Do you have Bentley or another manual that give the instructions to do this? If not, try a search on "John Walker" and "idle adjustment" and you should find the instructions.

Tim

kqw · 01-21-2005, 04:16 PM

When was the last time the O2 sensor was replaced?

DonMo · DonMo's Garage

I made my 84 Carerra idle problems go away by doing a couple of simple things.

Check for vacuum leaks (including intakes, use carborator cleaner to spray around lines and intake, not near air cleaner, if idle goes up, you have a leak)

Set idle per factory spec

Have air/fuel mixture set right (need CO2 meter to do right)

ZOA NOM · ZOA NOM's Garage

CO adjustment wound up fixing mine, after a full airflow meter refurb and vacuum leak hunt. One note- the airflow meter had developed a "worn spot" on the resistor film that provides the voltage sample to the DME, which cause it to act funny.