Idle keeps reving up and down
#1
Idle keeps reving up and down
I have a 95 ex and its usually in the morning or if its cold at night that i will drive my car and after about a couple of blocks my car will just keep reving up and then down when im stopped. Whats the problem with this and what can i do to fix it? Thanks
#5
RE: Idle keeps reving up and down
If you have access to a scan tool, check the number of steps the IAC motor is set to. If the computer is telling the IAC to stay at one spot, and it isn't, then there most probably is a problem with the IAC. And if the computer is telling the IAC to change, there might be another sensor that is broken or something.
#6
RE: Idle keeps reving up and down
Same thing happened to my brothers Ford Fiesta 1.25 zetec after he installed a K&N style air filter. This is because the intake air temperature module that connects into the airbox had to be removed in order to fit the new filter. The problem comes as they are designed to be used in a chamber and not out in the open. This will then send incorrect signals to the ECU, and cause it to inject the wrong amount of fuel. If you have moved the sensors location in order to fit an induction kit, this is probably why you are experiencing a fluctuation in idle speed.
=chris=
=chris=
#10
RE: Idle keeps reving up and down
Well klaibert your car is supposed to idle pretty high when turn it on cold. It helps the engine warm up to operating temperature faster. And this idling problem you guys are talking about, is it like right after you take your foot off of the gas pedal, and it is trying to return to idle, but it will jump up to like 2300 a couple times and then go to normal idle? Because mine always does that in cold weather, but it goes back to normal in the summer. Doesn't seem to be hurting anything.