High idle

[alinski]

Hi- I'm brand new so please bear with me. My '86 Ranger runs beautifully and has since I bought it in 1987. However, today out of nowhere, after a 5 mile trip I noticed that the idle had increased dramatically. I don't know what the RPMs are, but it's high enough to move along in first by itself.
I have limited mechanical abilities but can do moderate repairs. Can anyone give me some suggestions as to what the problem may be? It's fuel injected so there's no carb to fiddle with. Thanks-alan

2.3L, std. 5 speed, 160,000 miles

 

[ILLEGALCONCEPTS]

I would guess you need to start checking vacuum lines. You can use starter fluid and spray small areas at first. If the leak is there, the RPM's change. Then you have to pin point the leak from there.

James

 

[alinski]

Thanks for the starting point James. I'll start checking in the morning

 

[alinski]

OK, I did that. I found a leak that sounds like it's coming from the EGR valve. I replaced the gasket to no avail. Listening again, the loud hissing is coming from the passenger side of the EGR where there are holes all of the way around the unit. Is that supposed to be the case? I don't think it is so what's the cure? Other than buying a new valve (I'm disabled and poor! L0L), can I first clean the old one thoroughly (should have done this the first time) and see what happens? I did notice quite a bit of carbon deposits but only lightly scraped. Help, PLEASE

 

[Bryan22]

On the back of the throttle body (between it and the firewall) you'll find what's called an IAC (Idle Air Controller) Take it off (2 bolts) and spray the inside of it and the inside of the throttle body with some throttle body cleaner (make sure it's o2 sensor friendly) buy a new gasket put it back together and i bet that fixes your problem.

 

[Bryan22]

P.S. If you're worried about the EGR valve disconnet the vacum line going to it and hook up a vaccum pump. at 10 pounds of vaccum it should just about kill the motor. if nothing changes with 15 pounds of vaccum it's bad. if it tries to kill the motor it's good.

 

[alinski]

To the two of you who took the time to try and help me, Bryan and James, the problem did indeed turn out to be the EGR valve. After getting a used one today at a pick and pull yard, and comparing the action to the non-action of my old one, it was obvious then where the problem had been.
It runs great and again and a big thanks to the two of you!
alan

 

[ILLEGALCONCEPTS]

Glad to hear you got it running right again. I hate when I spend time on something and still have the same problem. I feel like I wasted what ever time I spent and to me that's failing. I don't like to fail at anything I do LOL

James

 

[Bryan22]

no problem man hope it was helpful.