what causes idle up while coasting?
01-23-2015, 11:58 PM
#1
what causes idle up while coasting? So just did heads and a few other things while i had the car up:
installed wideband
cleaned up some wiring
ati install
Im asking this as a general question to minimize the "obvious" reasons because i think its something i over looked when putting the car back together.
Symptoms:
idle perfect at stop.
start moving and idle will raise to 2k rpm
Car previously had good running cam only tune. I did drill the tb out a little more too.
installed wideband
cleaned up some wiring
ati install
Im asking this as a general question to minimize the "obvious" reasons because i think its something i over looked when putting the car back together.
Symptoms:
idle perfect at stop.
start moving and idle will raise to 2k rpm
Car previously had good running cam only tune. I did drill the tb out a little more too.
01-24-2015, 06:48 AM
#2
Most people call that the 'cruise control' effect. Its caused by too much idle air. When the car is still, Idle trims close the IAC to keep the RPMs in check. When moving the idle trims are not engaged and if the airflow is too high, it will idle up like that. Too much fuel and timing also contribute, but I suspect it is the tb drilling that is causing it in your case.
01-24-2015, 09:04 AM
#3
Most people call that the 'cruise control' effect. Its caused by too much idle air. When the car is still, Idle trims close the IAC to keep the RPMs in check. When moving the idle trims are not engaged and if the airflow is too high, it will idle up like that. Too much fuel and timing also contribute, but I suspect it is the tb drilling that is causing it in your case.
