Mind of its own; Revving by itself

[Ranger379]

well i was driving today and just as i pulled off the main road onto a side street i let off the gas and i dont slow down, light on the brakes and didnt slow down....uh wtf....push clutch in and the engine rev's to about 3500 rpm, so i turn the key off. waited a second, and started it back up and it did it again, checked my floor mats that the pedal wasnt stuck down, did it over again still revved up, luckily i just shut the engine down and my stop was just another 100 feet. checked gas pedal, checked the throttle cable and such and all is fine, what the hell would do this? after i checked that i started engine again and it was fine, parked it, the trip home was fine... i was going to pull the cruise control fuse thinking that was it and the 4x4 tail lights etc are on same fuse. any help is greatly appreciated, thanks

 

[IAmTodd]

Probably the IAC(Idle Air Controler). <$50 part at Advance Auto and an easy change.

Where are you from in PA?

 

[Bigg_billy]

Tru Dat.........

 

[Ranger379]

IAC? never thought it would be that, can someone explain y that would rev the engine? i will go buy one this weekend and put one on. ya they are really easy change, i cleaned it on the 95 thinking that was the rought idle. im from titusville really small town, i relation to bigger cities: i am an hour south of eire and im about 3hrs north of pittsbugh

 

[97greenmonster]

It will think its letting to much in, then not enought, then too much, and its a cycle. Basicly, if you havent replcaed it on your truck, you should, because its going to crap out sooner or later. I had to replace mine, every explorer ive looked at to buy has a new one, my friend needs a new one. Its really really easy to replace. REALLY REALLY EASY.

 

[Ranger379]

ya ill get one this weekend, ya it cant be any easier, one wire connector and 2 bolts, i cleaned the one on the 95 before, everyone is positive it is the IAC tho, dont have money to replace crap right now, inspection runs out in a month and got hella lot other stuff to fix. could it be anything with throttlebody/ TPS anything like that, or cruise control? thanks again

 

[97greenmonster]

Yea, it probly is. If its running fine now, i wouldnt worry about it until it happenes again. Since you have a clutch, if it dost it again, youll just have to keep it reving up higher till you buy the part. Like i said, dont waste the money if it only happened once. When mine went out, it wouldnt idle at all. Period. the only way to keep it running was to keep my foot on the gas at about 1500, i have an auto tranny tho.

 

[Ranger379]

Yea, it probly is. If its running fine now, i wouldnt worry about it until it happenes again. Since you have a clutch, if it dost it again, youll just have to keep it reving up higher till you buy the part. Like i said, dont waste the money if it only happened once. When mine went out, it wouldnt idle at all. Period. the only way to keep it running was to keep my foot on the gas at about 1500, i have an auto tranny tho.

well i bought the part today at advance auto less than 50 bucks, the problem is that that it wont idle corretly, i was driving and i pushed the clutch in and it reved up to about 3500-4000 rpm all by itself

 

[Ranger379]

Question on the IAC, the new one came with a gasket, it doesnt look like there is a gasket on the one right now, im gonna put the new one on with the gasket, but would not having a gasket cause a vaccum leak? thanks

 

[wired_af]

This happened to a friends car just a couple days ago. We replaced the IAC and that didnt fix it, it ended up beging the throttle position sensor, so add that to the list too.

 

[Ranger379]

i thought of the TPS, o well ill add that to the list, pretty soon ill have a a new truck keep replacing stuff lol o well, got the IAC on a min ago, put the gasket on, and as i said, the old one didnt have one, it was all crappy around it, dust or something inbetween the intake and iac, it idles better now, about 900 RPM rather than 1200-1300 so i guess it was worth the 50 bucks, lol should have tried the TPS first its only 38 bucks from fastpartsnetwork, i may order one

 

[Ranger379]

if per say it would happen again, and i will have to shut the engine off (to obviously prevent it from blowing up lol) is there anything i can do to make it stop doing that? took about 15 minutes before it would not do that, planning on a long trip this coming weekend, dont wanna have this happen going down the highway and not the power steering/brakes haha. if i have enough money ill replace it before then but if not then i cant, unplug TPS? anything? thanks

 

[Ranger379]

bump - should i replace the TPS? dont want this happening again, especcialy b/c at work ill run out 10-15 minutes early and start it so motor it warm when i leave, i would have the luck of it revving up by itself while im not there lol. thanks