HIGH IDLE
Thread Starter
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Fleet Owner
Joined: May 2009
Posts: 21,437
Likes: 76
From: Gilbert, PA
HIGH IDLE
My 04 ranger is back at it AGAIN.
It started about 3 years ago. Cruising along on the highway and then come into town. Idles at 2000 RPM
Shut it off. and restart it. Again, 2000rmp.
Shut it off and it idles normal
drive it 2-3 day and then it idles high again
I have clean and functioned the IAC and it works fine
Cleaned throttle body and I never can get it to stick.
Replaced throttle cable
it still was idling high
replaced ECM and it idled normal for about 1 year
replaced em again and it idled normal for about 6 months
it is back at it again
For what ever reason the EM is telling the IAC to open up and raise the idle
Suggestions?
It started about 3 years ago. Cruising along on the highway and then come into town. Idles at 2000 RPM
Shut it off. and restart it. Again, 2000rmp.
Shut it off and it idles normal
drive it 2-3 day and then it idles high again
I have clean and functioned the IAC and it works fine
Cleaned throttle body and I never can get it to stick.
Replaced throttle cable
it still was idling high
replaced ECM and it idled normal for about 1 year
replaced em again and it idled normal for about 6 months
it is back at it again
For what ever reason the EM is telling the IAC to open up and raise the idle
Suggestions?
Moderator
Joined: Jan 2004
Posts: 13,851
Likes: 111
From: SW Va
Which engine, tranny & body does this puppy have??? Have you used your ELM scantool to look for pending, or set trouble codes, if so post All code Number clues.
Have the scantool run & post the STFT & LTFT numbers & any other suspect data it finds.
Have the scantool run & post the STFT & LTFT numbers & any other suspect data it finds.
Thread Starter
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Fleet Owner
Joined: May 2009
Posts: 21,437
Likes: 76
From: Gilbert, PA
Has zero vacuum leaks and the PCV has been changed with zero difference
Cargo Master
Joined: Feb 2002
Posts: 2,414
Likes: 22
From: Tucson USA
Ive got a 94 that had hi idle issues like you describe. I disconnected the idle solenoid and later had a guy with all the books do a system search and he came up with a short somewhere in the main wire harness. Have run with the solenoid disconnected for many ears now, did turn the idle stop up, but have no issues with idle with ac on or anything. give it a try and see if it helps.
Moderator
Joined: Jan 2004
Posts: 13,851
Likes: 111
From: SW Va
Post up the short & long term fuel trim numbers. That should give us an idea if you have a vacuum leak some where that's not obvious.
When its at warm idle, what happens when you Disconnect the idle air control electrical connector???
When its at warm idle, what happens when you Disconnect the idle air control electrical connector???
Thread Starter
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Fleet Owner
Joined: May 2009
Posts: 21,437
Likes: 76
From: Gilbert, PA
Disconnecting the IAC does nothing when it has the high idle
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Moderator
Joined: Jan 2004
Posts: 13,851
Likes: 111
From: SW Va
Ok, disconnecting the IAC should cause the idle rpm to drop, maybe run rough, or stall, so with Nothing happening when its electrical connector is disconnected, suggests its not working properly. Its a common problem part & cleaning might not last, it didn't for me but was a good trouble shooting step before replacing mine with a BWD one & with a online discount code, from Advance Auto. Motorcraft, or BWD are recommended if you find its replacement time.
If your scantool will read fuel trim post up the numbers.
If your scantool will read fuel trim post up the numbers.
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Moderator
Joined: Jan 2004
Posts: 13,851
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From: SW Va
I know you believe replacing the PCV valve & spraying carb cleaner around under hood has eliminated the possibility of a vacuum leak & the cleaner put in the right place can help find a large leak, but it can't get everywhere a vacuum leak can occur & you don't need much of a leak to raise the rpm up to 2000.
So fuel trim numbers can tattle on minute vacuum leaks, as well as fuel injectors with a runny nose & can tell us which cyl bank may be the problem, so fuel trim numbers can be useful for other than detecting vacuum leaks & might be helpful in this diagnosis.
So if your snap-on can read the Rangers fuel trim, consider having it do so & post up the Numbers.
So fuel trim numbers can tattle on minute vacuum leaks, as well as fuel injectors with a runny nose & can tell us which cyl bank may be the problem, so fuel trim numbers can be useful for other than detecting vacuum leaks & might be helpful in this diagnosis.
So if your snap-on can read the Rangers fuel trim, consider having it do so & post up the Numbers.
Thread Starter
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Fleet Owner
Joined: May 2009
Posts: 21,437
Likes: 76
From: Gilbert, PA
Ok, let me say it again a little differently
The problem started one day on my way home from work 3 years ago and 75k ago.
Ended up changing the ECM, problem went away for about one year and 25k.
The problem came back. Change ECM again, The problem went away for another year or so and 25k
I'll see if my scanner can see trim levels
The problem started one day on my way home from work 3 years ago and 75k ago.
Ended up changing the ECM, problem went away for about one year and 25k.
The problem came back. Change ECM again, The problem went away for another year or so and 25k
I'll see if my scanner can see trim levels
Moderator
Joined: Jan 2004
Posts: 13,851
Likes: 111
From: SW Va
With there being No change in idle speed when you disconnected the IAC electrical connector with the engine at idle, put the IAC high up on your suspect list. EDIT: Seeing as how you've gotten positive results after changing out the engine computer a couple of times, also put the IAC wiring & pins/sockets connections at the computer firewall electrical connector on the suspect list too.
Senior User
Joined: Aug 2004
Posts: 352
Likes: 0
From: Waukesha, WI
Had problems on my 87 F150 years ago, RPM would not drop below 1700, intermittent. Problem was the plate in the throttle body was not closing completely due to gummed bushings. Made it real fun stopping and sitting at stop lights.
Thread Starter
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Fleet Owner
Joined: May 2009
Posts: 21,437
Likes: 76
From: Gilbert, PA
With there being No change in idle speed when you disconnected the IAC electrical connector with the engine at idle, put the IAC high up on your suspect list. EDIT: Seeing as how you've gotten positive results after changing out the engine computer a couple of times, also put the IAC wiring & pins/sockets connections at the computer firewall electrical connector on the suspect list too.
I am guessing a pinched or corroded wire somewhere
Moderator
Joined: Jan 2004
Posts: 13,851
Likes: 111
From: SW Va
While your inspecting the IAC wiring on both of its run, also inspect the electrical connectors pins/sockets for pushed back/unseated, not locked into place pins/sockets, loose crimp, bent, or corroded pins/sockets, ect & let us know what you find.
Right now, with the idle speed Not responding to having the IAC electrical connector Disconnected, the IAC belongs pretty high up on your suspect list.
Right now, with the idle speed Not responding to having the IAC electrical connector Disconnected, the IAC belongs pretty high up on your suspect list.