2007 Apex/Attak-HIGH idle issue

[mbarryracing]

For an engine to idle at 4500 rpm, it needs a good amount of air. Look for a source of that excessive air. I'm leaning (no pun intended) towards the IAC assembly is somehow involved. The reason I say that is the Apex IAC works sort of like a thermostat, but opposite. As the coolant gets warmer the wax expands and it is supposed to close off. Sounds like it's staying open. You could plug off the inlet tube that feeds air from the airbox, see if that drops the RPM down... if so, start there.

Like I said before, the IAC reacts to coolant temp. The coolant has to be flowing thru it in order for it to warm up and move like a thermostat... If you can't blow thru it, then it's not getting coolant flow either and not closing off as it warms up... meaning not closing off the air flow to control the idle RPM down... The reason I also said to plug off the air supply line to see if it drops the RPMs...

 

[NY AttakGT]

Like I said before, the IAC reacts to coolant temp. The coolant has to be flowing thru it in order for it to warm up and move like a thermostat... If you can't blow thru it, then it's not getting coolant flow either and not closing off as it warms up... meaning not closing off the air flow to control the idle RPM down... The reason I also said to plug off the air supply line to see if it drops the RPMs...

Thanks. I must have overlooked the "plug off air supply and see if it idles down" portion. Can the IAC or at least the coolant portion be bypassed, maybe rigged so internal spring is compressed mimicking hot coolant flowing through? If this is even the issue, just curious if I could bypass or "trick" the coolant portion, at least and put something in there to compress the internal spring making it think engine is warm.

 

[NY AttakGT]

Some follow up...it was the IAC valve and the fact the coolant portion was plugged up. Dropped it into a pot of boiling water to see if it would open (like a thermostat) but it didn’t move. Blew through one of the coolant nipples again and must have blew threw a wade of gunk blocking coolant passage. Put it back together, started it up and it is now idling like it should. This portion of IAC valve which is bolted to the top of throttle body rack.

 

[TBay Sledhead]

Glad you got it fixed.