A month or so ago the CEL came on in my '93 4.0 auto ranger. I was cruisin at about 60 and it jumped down a gear(pretty hard) and never would go back into OD. Then i find that it doesnt idle very good and even dies sometimes. I've covered the small things like, IAC and MAF. Every now and then the light goes off, OD comes back and all is well for a few minutes. And if it has anything to do with it at all, my valve cover started leakin at about the same time..im stumped. Anybody have any ideas...this thing is drivin me crazy.

 

The CEL is telling you that a Diagnostic Trouble Code is stored. Until you know the code or codes, you will just be guessing.

 

I know when this happend to me in my Bonneville, it was the TPS that was off. That car had an adjustable one. When it needed to be adjusted a CEL light came on and would not shift into OD. Just a thought.....

 

I changed the TPS, still nothing. Autozone ran the scanner on it and they told me the EGR valve was messed up....it doesnt even have one....

 

Finally got it fixed. Apparently the MAF was more than dirty. I replaced it and everything is good to go.