High Idle: TPS or IAC?
Thread Starter
CF Veteran
Joined: Nov 2011
Posts: 2,433
Likes: 6
From: Northern MN
Year: 1990
Model: Cherokee (XJ)
Engine: Renix 4.0
I cleaned my throttlebody today, put everything back together, and now I have an idle at ~1000rpm after start up, and 1100-1300 after driving a little bit. In gear it drops to 700rpm. I tried adjusting the TPS, it's a renix btw, with no luck so I put it back to where the indentations were previously. Any ideas?
EDIT: I followed Cruiser's write up and could not get terminal D to read 83% of B's voltage. It stayed around .85V
EDIT: I followed Cruiser's write up and could not get terminal D to read 83% of B's voltage. It stayed around .85V
Last edited by austinjoe13; May 12, 2013 at 10:18 PM.
Thread Starter
CF Veteran
Joined: Nov 2011
Posts: 2,433
Likes: 6
From: Northern MN
Year: 1990
Model: Cherokee (XJ)
Engine: Renix 4.0
I don't think so, but I'm gonna check it out tomorrow. I did forget the MAP hose at first though. It sounded like it was cammed and smelled like gas lol.
Thread Starter
CF Veteran
Joined: Nov 2011
Posts: 2,433
Likes: 6
From: Northern MN
Year: 1990
Model: Cherokee (XJ)
Engine: Renix 4.0
The TPS is shot. I hooked up two multimeters and the D circuit never rose past .844v while the B circuit went from 4.5-5v. So I'll be getting a new one soon :P
Trending Topics
Thread Starter
CF Veteran
Joined: Nov 2011
Posts: 2,433
Likes: 6
From: Northern MN
Year: 1990
Model: Cherokee (XJ)
Engine: Renix 4.0
Ok, I got the new TPS on today. The tranny shifts MUCH better! But I've still got the high idle. Would the IAC cause this? I am but a young padawan, Master Cruiser 
The idle bounces between 1000 and 1200rpm every 5 seconds or so

The idle bounces between 1000 and 1200rpm every 5 seconds or so
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,579
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Adjusted the TPS on which connector? The flat 3 wire or square 4 wire one?
The flat connector, engine side, is the most critical. The trans side is quite forgiving. Therefore use the engine side for sure and see what you get.
The flat connector, engine side, is the most critical. The trans side is quite forgiving. Therefore use the engine side for sure and see what you get.
Thread Starter
CF Veteran
Joined: Nov 2011
Posts: 2,433
Likes: 6
From: Northern MN
Year: 1990
Model: Cherokee (XJ)
Engine: Renix 4.0
Yes, I did and the resistance was between 1 and 2 ohms. So I'll have to clean that up and replace the battery cables and engine ground.





