66stingray
Member
- Joined
- February 28, 2014
- Messages
- 24
- Reaction score
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- Year, Model & Trim Level
- 2002 Mountaineer
I posted a while back regarding cel light and codes i got with the mounty p0171 and P1152. They eventually went away and found out the probable cause, i had the infamous broken rubber elbow connecting the pcv valve and the throttle body,
Anyway, My erratic high idle ( meaning it revs high usually at start up to 1,500 or higher before settling down after a couple of minutes and if I blip the throttle it usually hangs high before kicking down to normal ), didn't start happening until I did a fuel pressure test. After I hooked a gauge to the fuel rail, my idle has gone bonkers. Read up a bit on idle conditions, found the vacuum leak with the broken elbow and I replaced the assembly. While I was at it I replaced the pcv valve. Still the same. Replaced the IAC valve with a standard brand and thought that initially cured it, but after a day of driving it returned to the same condition. Cant find any other obvious vacuum leaks. Thinking the only thing left would be the TPS sensor, I replaced that, still no change.
Idle is high at start up, blip the throttle and it hangs for a while before kicking back down. Driving the car, coming to a stop, the tranny kicks back to first and idles high, making the car surge and then after coming to a stop, kicks back down to normal idle. I read numerous posts regarding the issue and the cause usually is a vacuum leak, but can't find any other than what I found before. I have no current cel codes. I am at a loss. My remaining theory is that the IAC valve took a dump after a day and was thinking of getting a Motorcraft one.
Btw, my fuel pressure readings were within specs when energizing the fuel pump, no loss of pressure after shutting the motor off, but was 3 psi higher than spec in running condition, 68 vs 65 psi. Don't think this is a major issue.
Anyway, My erratic high idle ( meaning it revs high usually at start up to 1,500 or higher before settling down after a couple of minutes and if I blip the throttle it usually hangs high before kicking down to normal ), didn't start happening until I did a fuel pressure test. After I hooked a gauge to the fuel rail, my idle has gone bonkers. Read up a bit on idle conditions, found the vacuum leak with the broken elbow and I replaced the assembly. While I was at it I replaced the pcv valve. Still the same. Replaced the IAC valve with a standard brand and thought that initially cured it, but after a day of driving it returned to the same condition. Cant find any other obvious vacuum leaks. Thinking the only thing left would be the TPS sensor, I replaced that, still no change.
Idle is high at start up, blip the throttle and it hangs for a while before kicking back down. Driving the car, coming to a stop, the tranny kicks back to first and idles high, making the car surge and then after coming to a stop, kicks back down to normal idle. I read numerous posts regarding the issue and the cause usually is a vacuum leak, but can't find any other than what I found before. I have no current cel codes. I am at a loss. My remaining theory is that the IAC valve took a dump after a day and was thinking of getting a Motorcraft one.
Btw, my fuel pressure readings were within specs when energizing the fuel pump, no loss of pressure after shutting the motor off, but was 3 psi higher than spec in running condition, 68 vs 65 psi. Don't think this is a major issue.