87 Cherokee..BIG PROBLEM...little other questions..

[seanwheelz]

1050801

I just bought a 87 cherokee with a 4.0 and a 5 speed 91k. I noticed that when it sits for more that 2-3 days, it idles very fast for about 20 minutes for aboput 2 days. After that it calms down an idles normally. Now, I just did a ton of work to squeeze it past strict NYS inspection. Part of my work include a full exhaust inc. cat. Now, I was under the hood for some reason late one night.. and I noticed that my exhaust manifold was glowing red(NOT GOOD). I then noticd the next day when I was poking around that the jeep was idling correctly and that the pipes were no longer glowing. Now, is it possible that I installed that cat backwards???? or that I have a bad sensor somewhere??? Someone suggested that I adjust the timing, but the truck runs well most of the time...only when the idle starts racing on its own......Any help/suggestions would be greatly appreciated.



Also, how can I tell if I have command-trac or select-trac? Most of the 'nameplates' on the jeep are gone and the guy I bought it from had no idea...just curious.



Sean [addsig]

 

[pinaplebob]

1050813

I belive that command track has only 4H and 4L.



While select track as 4h Part time and 4H full time and 4L



I'm pretty sure that is the difference?

Anyone know for sure?[addsig]

 

[Timl]

1050865

Correct on the Command Trac difference. As for adjusting timing I would say Yes in the old days (before computers controlled everything) because I experienced that exact situation with an old International 6 cylinder. The manifold was completely cherry red and after adjusting the timing it had 2 small spots left. With computers though I would heistate to mess![addsig]

 

[seanwheelz]

1051371

Isn't my jeep computer controlled? According to my manual, you can't control the timing, outside of just replacing the chain...or is the book wrong?? I've come across mistakes in these haynes books in the past. Although, according to this book, there is no way to check for error codes/malfuctioning sensors...or maybe I'm just babied by my saturn that has a central control...[addsig]

 

[XJNick]

1051465

I had the same question about the computer on my '88 cherokee. It turns out the computer in these pre '91? cherokees doesn't store error codes. This is verified if you have no "CHECK ENGINE" light. All you can do is monitor what the car's computer is doing through a scanner.



Note: The "EMISS MAINT" light is not controlled through the car's computer



Hope this helps

-Nick[addsig]