What RPM does your car idle at?

Did you have a lot of issues tuning it to stabilize the idle?

Reason im asking, I just got my cam and heads installed and im having some issues. The car was dyno tuned after installation. When I start the car it won’t hold a steady idle for several minutes. It fluctuates from 800 to 1800 RPM then holds steady at around 1100. The car also holds an idle better with the AC on.

Is this normal or can this be resolved with tuning?

I am also having issues with the motor racing after I have been on the highway for a period of time. It will idle at 1800 to 2000 RPM for several seconds after coming to a stop. I was told I might be an issue with the throttle body sticking.

Any information would be greatly appreciated. Thanks.

 

I dont have mine back yet but thats definitely not right. Your tuner should be able to tune the idle smooth. I dont know how you wrote that so small but it was tough as heck to read please adjust fire on the print size.

 

im having the same problems when i get off the highway, its the definitly the tune

 

Sounds like a bad IAC motor. I would try to clean it out first then check with tuning. Scan the computer and see if you have codes. They may have left something unplugged.
-Alex

 

Bump

 

it is all in the tune, mine does the same thing, when I put my stall in there it helped out alot and had more of a steady idle.

 

I hope it can be resolved with further tuning. Its not terrible and the car is drivable but i think it could be better. This is my first big cam so what im describing as unusual might be the norm. Thanks for the replies guys.

Any other MS3 owners with issues?

 

Def a tuning issue. Your issues you describe should not happen. You should also consider SD (speed density)tuning. Its alot more accurate and eliminates the common big cam issues like:

-hot starts
-idle hunting
-surging and bucking
-poor driveability

best of all, car will idle like stock, very smooth. There will no longer be a MAF unit. The closest SD master tuner to you is ECS. Give them a call.

 

Clean the IAC as carbon can accumulate and mess things up.
Do a TPS relearn (shut ignition off, unplug TPS, turn ignition on,wait 15>30 sec, turn off, plug TPS and start car)
You can the repeat this process after adjusting idle screw at the TB for desired idle speed till you are more satisfied.

 

Excuse the dumb question but where is the IAC located? Is it part of the throttle body assembly?

Also i have heard about instances where people drilled a tiny hole in the throttle body blade. Why is this done?

Thanks

 

The IAC valve has a pink arrow pointing to it in the picture below.