1988 Cherokee rough idle
 

I recently traded for a 1988 Jeep Cherokee. 4.0, auto, 166k miles. The previous owner replaced, plugs, wires, cap, rotor and did the neon injector swap. It idles up and down but runs smooth and has plenty of power (for a 6 banger) when you drive it. It also black smokes when you rev it up. I cleaned the throttle body and changed the fuel filter. I also pulled some vaccum lines off to see if it ran and worse (no change). You also have to pump the gas a few times to get it fired up. I've never messed with the renix system. Any suggestions?

Thanks
JR

Hey JR. The MAP sensor there up on the firewall has a delicate little tube running down/up to the little rubber plug on the TB. That's gotta be really nifty because if the MAP doesn't get good vacuum it.. will......run like yours! (Think you have your foot in it and tell your ECU to dump more fuel). :thumbup1:

(Your Renix Jeep will cut off the fuel and give it nothing but air if you floor it, cranking) Idk. What the smarter ones do.

Excellent place to start.