hi, finally i found my surging idle problem the fitv plunger was broken inside. Block-off the fitv and nice idle at 1k, no cold start problems. When i try to
set the idle to 800rpm unplug the iacv but the idle screw is all the way adjust.
Take off the throttle cable and stay at 1k, maybe need to clean the throttle
for proper closing.

Tuning on crome target idle 750rpm, injectors 650cc. But always idle at 800-850 on the stock tach. From the dyno tuning 6 or 7 months ago never have a
problem to last week, from remove the fitv i need to tune the car again, i don't think so.

 

Start by cleaning the TB.

Any CEL codes?

If you cover the FITV or IACV port in the TB with your finger, does the idle speed drop?

 

no codes, throttle clean working on it.


thanks

 

ok, clean the throttle, start the car No CEL but now seat at 1.2k when fully
warm. Vacuum leak?

 

change the iacv for one used but well know working and the idle seat at 800rpm. Now check on the street after few minutes of drive stop in a light and hope the bounce not return.