espot77

Got this jeep a month ago from a friend who had problems with a rough idle.

It was working smoothly for a week then the idle started to stumble bad, usually go up and down from 100rpm to 1000. After looking at the vacuum lines the MAP sensor line was in the wrong hole for the TB. After its attached the idle goes up to 1900rpm then climbs to 2200rpm and stays there. Also a little black smoke, indicating rich fuel mixture, would come out the back when the map sensor was not connected and go away when connected but at high idle

Previous work done;
cleaned the grounds, changed out the TSP, IAC and CPS,cleaned out the TB, replaced the vacuum lines (the harness and single lines), changed the spark plugs and wires, cleaned out the distributor cap, checked fuel pressure at rail, changed fuel injectors to 4 pin and rail.

I checked the MAP sensor thinking maybe it was bad and replaced it today but it was the same results.
I'm gonna check the fuel lines to see if they are clogged tomorrow, thinking that the renix system is over compensating.
Im really puzzled

Creature85

I don't think a restriction of fuel is going to cause a high idle. Honestly sounds like a vaccum leak to me. Did you have your throttle body off when you cleaned it by chance?

Creature85

Also, what year and model Jeep do you have?

espot77

89 base 4wd. 255k miles
Took the TB off to clean it and made sure the gasket was on correctly. Also check all the vacuum lines one by one with soapy water and compressed air running through them.
I think that maybe its still a grounding problem. Driving it this morning it idles down a little bit. Thinking I might need to re ground the TSP.