High Idle

[sphillips]

I know there has been much written about this issue, but I would like to throw it out there again. I just purchased a 2000 XLT with 77,000 mile on it. It runs like a champ but it idles high. No CEL's, hooked up the scanner, no codes, runs smooth at all rpm's. Drove it for 1.5hrs Saturday, put it in park, idled at
1000 rpm. Issues are difficult to trace when no smoking gun such as a code.

Thx for any help,

steve

 

[2004XLT]

I would start simple, unhook the battery and clean the throttle body and maf sensors, reconnect the battery after one hour then go thru the idle relearn procedure:

1.) start it in park with all accessories off
2.) idle till you reach operating temp
3.) turn ac on max, idle for one minute
4.) put in d while still running and ac on, let it idle for one minute
5.) go for a short drive see if that changes your idle

 

[Bedrck47]

What engine is in the expy??

 

[1955moose]

Just so you have a reference my 2000 5.4 idles at 775 rpm in park, and 675 in drive.


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[sphillips]

Thx to all for the input. I have a 5.4l engine. I'll give 2004xlt's test this weekend, if it warms up, been below 0 every morning for the last week

Thx again!

 

[stamp11127]

If the relearn isn't effective try this:

https://www.2carpros.com/articles/engine-idles-too-high

 

[docraymund]

Check the IAC valve. Ignition on, probe connector harness side with volt meter. Should be 10.5 to 12.5 volts. If ok, check resistance of terminals of the valve itself should be 6 to 13 ohms. And check for short circuit (probe terminal and valve body) should be more than 10000 ohms. Good luck!

 

[sphillips]

Check the IAC valve. Ignition on, probe connector harness side with volt meter. Should be 10.5 to 12.5 volts. If ok, check resistance of terminals of the valve itself should be 6 to 13 ohms. And check for short circuit (probe terminal and valve body) should be more than 10000 ohms. Good luck!

Is it a 2 pin connector, one power and one ground?

Thx

 

[1955moose]

It is a 2 pin connector, at least on first generations, that's a great voltage/ ohm check Doc, thanks that should help from a lot of replacing of good parts.


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[Coey326]

I had the exact problem and went through all the test. When its was all said and done it was the IAC that went bad. A 10 minute fix and no problems since. Good luck

 

[sphillips]

I would start simple, unhook the battery and clean the throttle body and maf sensors, reconnect the battery after one hour then go thru the idle relearn procedure:

1.) start it in park with all accessories off
2.) idle till you reach operating temp
3.) turn ac on max, idle for one minute
4.) put in d while still running and ac on, let it idle for one minute
5.) go for a short drive see if that changes your idle

Went thru these procedures, idles at 950, so slightly better

 

[sphillips]

I had the exact problem and went through all the test. When its was all said and done it was the IAC that went bad. A 10 minute fix and no problems since. Good luck

Thx Coey

 

[sphillips]

Installed a new IAC valve and idle when hot is 725, much better

 

[1955moose]

Glad you got your idle down. What brand did you buy that worked? It will help other members.


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[sphillips]

Sorry about late response. IAC is from Rock Auto, made by Hitachi. BUT, nothing lasts forever, idle is back to 950-GRRRR!

 

[1955moose]

Check one of the prior posts from one of our members.Doc Raymond, He had posted a way to test them if bad.


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[sphillips]

Check one of the prior posts from one of our members.Doc Raymond, He had posted a way to test them if bad.


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Will do. Also, realized the car has adjustable pedals which were adjusted all the way towards the seat. Moved them towards the firewall and idle came down to 800. Coincidence?

 

[sphillips]

Well, its fixed, but not sure why, someone will have to explain this to me. $4 part and 10min fix. I replaced the PCV valve and now it idles at 650, doesn't roar to 1700 on start, about 1300rpm and drops right on down.

 

[aircargoo]

i u\just seen this and had exact problem. i was going to inform you check your hoses ect....pcv valve leaking is like having a leak with a loose air filter. trucks idle goes up.pvc hose goes straight into throttle bodys rear/back....glad you found problem...

 

[sphillips]

Thx air cargo, good to have a resolution