I've been trying to figure this thing out for awhile now. Some of you may remember my other threads on this, but it's been lingering for awhile now, I can't get my car to Idle Right. First off i don't have a tach so the RPM's are quesstimated. Second i have a Zetec with a Manual Transmission.
I start up the car and Idle's fine without touching the gas. The car is completly up to operating temp.. I jump in the car and drive it down the driveway. I shift from 1st to 2nd and the Idle hangs, not bad, but enough to make the shift into 2nd jolt the car. Come to the stop at the end of the Driveway push in the clutch and stop and the ilde is at a quesstimated 2,000 RPM's. Not nearly as bad as my previous situation. And it eventually comes down, after about 10 - 15 seconds to where it should.
That isn't bad, but if i were to pull up next to somebody, say a cop, they would think i'm getting ready to race them, just by the sound of my engine and exhaust.
Second Problem:
I'm driving down a 25MPH road in 4th and my foot is completly off the gas, but I'm staying at 26MPH unless the road goes uphill or downhill and the speed changes accordingly. Once i level out it goes back to 26MPH. Push in the Cluth and the Idle goes up again to a high RPM (quesstimated under 3,000RPM's) and doesn't come down untill i'm stopped for atleast 10-15 seconds.
What I've Tried and Replaced:
I tried to change the TPS and there was no change, but this was BEFORE i change the IACV. But when i changed the Throttle Position Sensor, Nothing changed, but I also got a Code. It was a Throttle Posistion sensor Low Voltage code. Changed back to the original TPS and code went away. While i had 2 TPS's i took it to my buddies shop who has a scanner and he said the computer thinks that it was under 15% load with both TPS's. I took the new TPS back to the place where i got it for a refund. After that, I unplugged the IACV and the Car Idled like Normal, thus i thought i might have found my problem.
I just replace the Idle Air Control Valve and that had the most drastic change. Idle is not nearly as bad. But it still hangs with the same results before i changed the IACV but not nearly as bad. I've checked countless times looking for Vaccum Leaks and to no Avail. I've sprayed Throttle Body Cleaner all over the intake Manifold and all the Vaccum Lines and my idle did not change. I even went to an extreme and took a propane torch not lit (ofcourse) with the car idling and the idle did not change again [] But if i Unplugg the IACV, my car Idle's fine. I rev the engine, while not moving, and it comes right back down. Drive down the road with the same result idle comming right back down and not hanging and my speed comes down accordingly. The only problem i've found, is that my Check Engine light Comes on with the IACV Unplugged.
I'm at Wits End here. I don't know what else it could be. My Car is technically under warranty, but i'm not willing yet to have them look at it and have them say something stupid like my exhaust is causing the car not to idle right. I will if i have to, but at a last resort. I will probally try to change the TPS again, but i was wondering if anyone else had any input. I'm also thinking that i might have a double whammy. Meaning my IACV and TPS can be bad but the IACV was more dominate cause than the TPS. Or I could have gotten both 'bad' parts right out the box. Not Likely, but ya never know. Any Input would be appreciated.
Thanks! [thumb]
P.S.
If anyone is comming to the Meet on Sunday (Spring Into Focus), then by all means, see if you can fix it. it's becomming highly annoying, I'm half tempted just to leave the damn IACV unplugged and deal with a CEL.
I start up the car and Idle's fine without touching the gas. The car is completly up to operating temp.. I jump in the car and drive it down the driveway. I shift from 1st to 2nd and the Idle hangs, not bad, but enough to make the shift into 2nd jolt the car. Come to the stop at the end of the Driveway push in the clutch and stop and the ilde is at a quesstimated 2,000 RPM's. Not nearly as bad as my previous situation. And it eventually comes down, after about 10 - 15 seconds to where it should.
That isn't bad, but if i were to pull up next to somebody, say a cop, they would think i'm getting ready to race them, just by the sound of my engine and exhaust.
Second Problem:
I'm driving down a 25MPH road in 4th and my foot is completly off the gas, but I'm staying at 26MPH unless the road goes uphill or downhill and the speed changes accordingly. Once i level out it goes back to 26MPH. Push in the Cluth and the Idle goes up again to a high RPM (quesstimated under 3,000RPM's) and doesn't come down untill i'm stopped for atleast 10-15 seconds.
What I've Tried and Replaced:
I tried to change the TPS and there was no change, but this was BEFORE i change the IACV. But when i changed the Throttle Position Sensor, Nothing changed, but I also got a Code. It was a Throttle Posistion sensor Low Voltage code. Changed back to the original TPS and code went away. While i had 2 TPS's i took it to my buddies shop who has a scanner and he said the computer thinks that it was under 15% load with both TPS's. I took the new TPS back to the place where i got it for a refund. After that, I unplugged the IACV and the Car Idled like Normal, thus i thought i might have found my problem.
I just replace the Idle Air Control Valve and that had the most drastic change. Idle is not nearly as bad. But it still hangs with the same results before i changed the IACV but not nearly as bad. I've checked countless times looking for Vaccum Leaks and to no Avail. I've sprayed Throttle Body Cleaner all over the intake Manifold and all the Vaccum Lines and my idle did not change. I even went to an extreme and took a propane torch not lit (ofcourse) with the car idling and the idle did not change again [] But if i Unplugg the IACV, my car Idle's fine. I rev the engine, while not moving, and it comes right back down. Drive down the road with the same result idle comming right back down and not hanging and my speed comes down accordingly. The only problem i've found, is that my Check Engine light Comes on with the IACV Unplugged.
I'm at Wits End here. I don't know what else it could be. My Car is technically under warranty, but i'm not willing yet to have them look at it and have them say something stupid like my exhaust is causing the car not to idle right. I will if i have to, but at a last resort. I will probally try to change the TPS again, but i was wondering if anyone else had any input. I'm also thinking that i might have a double whammy. Meaning my IACV and TPS can be bad but the IACV was more dominate cause than the TPS. Or I could have gotten both 'bad' parts right out the box. Not Likely, but ya never know. Any Input would be appreciated.
Thanks! [thumb]
P.S.
If anyone is comming to the Meet on Sunday (Spring Into Focus), then by all means, see if you can fix it. it's becomming highly annoying, I'm half tempted just to leave the damn IACV unplugged and deal with a CEL.