i've had high idle issues since i bought the truck almost a year ago. I started investigating the cause of the high idle. I unplugged the IAC electrical connector and the engine died almost instantly. Is that what is supposed to happen or is the IAC bad? i'll be checking to see if i have the correct voltage to the IAC as soon as i can get ahold of a voltmeter.

Thanks

Keith

 

It sounds like the IAC is functioning right. How high is the idle? Some things to look for are vacuum leaks.

Also, a bad TPS usually causes high idle.

 

how can u tell if the iac is bad and were is it

 

it starts but it will not stay on if i don't keep my foot on the gas

 

If you have to keep your foot on the gas (throttle) to keep it running, then I would guess that you have a bad EGR valve. If that was your question.

 

No if he had to keep his foot on the gas i would say the iac motor is bad. Had a dodge neon in the shop the other day did the same exact thing. Turns out the iac was bad

 

Were Is The Iac Motor, If I Keep My On The Gas It Runs But If I Take It Off It Stops Running Thanks For Your Help AND SHOULD I CHANGES THE ERG TOO

 

you need to read codes.

iac is on the side of the throttle body.

do you have a manual yet?

get one if you do not have one.

 

Do It Have A Plug On It

 

You’re probably right about the IAC that would have been my second guess but I have had problems with EGR valve making them die.

It has a plug on it, here is a photo.

 

yes it has a electircal connector. I do have a manual. it doesn't have anything on diagnosis of the IAC only how to remove and replace it. how do i test my TPS? the idle is 2000. would a clogged exhaust system make a high idle?

 

This will tell you what you want to know about the TPS.

http://fordfuelinjection.com/index.php?p=30

 

Thanks 4 Your Help I Am Trying To Get It Running So I Can Take My Boat Out Thanks Again

 

You need a voltmeter to test it. subford provided that link which shows the wire connections and what readings should be.... but a 2000 idle really does sound like TPS.

bjthemadboater, yes that does sound like a completetly closed IAC valve (or really clogged up..which can be cleaned). subford mentioned the EGR valve...that is a possibility if the valve was stuck open...but if this was the case, the truck would run bad all the time.

 

i'll take a look at the TPS this weekend sometime. how long should it take to remove and check/replace the TPS?

Thanks

Keith