Help! Just bought a 88 cherokee with straight 6 and auto for my son and his new wife. Started and ran great at dealer, maybe because they warmed it up before we got there. Next day i go out and it is hard as can be to start and run, till it warms up then no problem.
I put some injector cleaner through it but am wondering what else i can check, need this thing right for them.
also, is the renix system real hard to troubleshoot?

Thanks for any suggestions.

Scott

 

Try this link : https://www.cherokeeforum.com/f2/cru...x-tips-153663/ :

Cheers

 

This^^. 1 through 5 for sure. Eliminates numerous potential issues.

And thanks Jon!!

 

As far as diagnosing a Renix problem, you will need a digital meter. (even the $5 Harbor Freight one will work OK, at least for a while) It's ECU stores no codes, has no memory, no "engine" light. You need to test things yourself. (often the case with the later OBD-I & II as well)

X3 on the Grounds. I cleaned mine and added one. (engine to body).

Btw, Renix always takes just a tad longer to start. The engine needs to complete at least one Rev, and get to 300 rpm before it will fire. With a good battery and connections, and all else right, you barely notice it though.

Just because it's so easy, and such a common problem, go ahead and "get familiar" with your MAP tube. Any little problem there and nobody will be happy.

>> There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage on that tube and it will be pig-rich. (black smoke, fouled black plugs). You can pull the line off the MAP and feel for vacuum with your finger. If it runs!

 

Yep. Looky here:

 

Guess I'll go ahead and stick that with the diagrams in my link. A picture is worth 1000 words! (but could you color the plug green?)