hey everyone i have an 87 2 door inline 6 4.0 my problem is that after a couple minutes of driving the idol stays up around 2000 rpm and will even make it up to 3000 some times and i cant figure out whats wrong with it ive replaced the iac and cleaned the throttle body and lubricated all the throttle linkage and hooked a computer up to it and it didnt say anything was wrong so ive hit a wall if anyone has experienced this befor or if you know anything about it i would love the help thanks.

 

T.P.S. maybe ?

 

Could it also be the cts? Or the ecu?

 

Check for vacuum leaks

 

Did all the lines replaced

 

I had this with my 89.... I have to remember what I did, besides chevron.....

Posted by: Dre

 

Ok. I had this problem last year, before I junked it. I kept turning the injectors and cleaned the components of the throttle body. Check the O-rings on the injectors. You have to clean everything on the throttle body. My IAC valve was gummed up from cheap gas. After you clean it, on a 1/4 of a tank dump chevron techron in. Run it for 10 minutes and try the next grade gas. That was how I fixed mine. Took me a month every spring trying to figure it out until last year.

Posted by: Dre

 

Check the breather tubes and spray cleaner in the MAP sensor. It might have a lil oil in it... Mine did.

Posted by: Dre

 

Ok thank-you for the help how much is that cleaner? Do you know what causes it?

 

Brake part cleaner or the wire cleaner.

Posted by: Dre

 

Anything that dries fast and doesn't have a build up. Brake part cleaner cuts the oil.

Posted by: Dre

 

What about the chevron stuff

 

And I've already cleaned tb what should I clean next and I replaced the iac and were is the map sensor

 

MAP sensors are crazy sensitive, you should only use a MAP sensor cleaner or else you're asking for problems.

 

2x

1987 -1990 xj Automatic Transmission? If yes read this:
http://autorepair.about.com/library/faqs/bl232i.htm