Still have a high idle issue once my jeep reaches temp. Cold start I idle at 1000 rpms. At temp I idle at 1500. I have replaced theTPS, IAC, o2, the vacuum system. Ccv system, added a battery ground, replaced the battery ground cable going to the dipstick, and replaced the ground going from the engine block to the firewall. Now I'm not real good with electrical. With the engine off, I'll take my volt meter and check the ohms between the battery ground and a bare piece if metal and I get 0.4. With the engine running I get on average 1.1. The number varies by how warm the engine is. I'm considering replacing the darn computer before I rip anymore hair out.

 

Did you Adjust your TPS? and what about the Crankshaft position Sensor?

 

Might check.out the map sensor too

 

The tsp is adjusted, and I thought a bad MAP would cause a horrible idle. Like stumbling. Maybe I should start taking map sensor readings!

 

On my 89 when I.had this problem it was the tps ,but I went thru it all and when I unhooked the map sensor from vacuum line it idle really high then hooked in back up and idled.fast that led me to the tps

 

Do you have a c101 connector?

Look under the hood on the driver side...right above the brake booster. If theres a connector there its called the C101. Take it apart, get some electrode/brake cleaner & a tooth brush and clean it up..I also used a tooth pick to get into the plug holes!
Then get some dielectrode grease, grease it up and put it back together!

Mine was doing this and that was the only thing I touched...as soon as it was clean my high idle stopped!

 

No c101, and I've thank my lucky stars too! Lol

 

I don't have a fuel pressure gauge, but could a bad fuel regulator cause a high idle? The jeep idles high but it's stable. Solid 1500.

Oh. With the lights on, my blinkers will still blink slow. Same with the fan speed turned up, but not as bad.

 

Would adding an additional ground. I'm thinking from the same firewall spot to a bolt off the fuel rail. Would that be counter productive?

 

What are the two wires connected to the side panel on the drivers side? They look like two ground wires and are apart of the big network of wires. The aux fan wires are in this network.

 

Good idea.

Grab your ohmmeter. At the flat 3 wire connector of the TPS is a brown with white tracer wire. Probe that wire and put your other probe on to the negative battery post. Should be less than 1 ohm resistance. If not, it's easy to fix.
What method did you use to adjust the TPS? TPSs have two sides if you have an auto trans. The engine side of the TPS can be bad but most instructions have you testing the trans side. That can send you on a wild goose chase.........

 

I have a manual transmission, but with an auto tps since it was cheaper haha. To adjust I just back probed the two sensor wires and set the tps to 0.82. What's this fix that you speak of? :-)

 

Good move on the auto trans sensor. Way cheaper.

I have a set of simple instructions for adjusting the TPS that I can send you if you PM me your email address.

Did you check the sensor ground circuit as I outlined in the previous post? It's super critical and takes 20 seconds to perform.

 

Not yet, but as soon as I'm off from work I'll do so. I'll also post my readings. I did a general ground test on the two main grounds last night. Engine running and hot. 4.49 was what I got. Pretty high number.

 

Have you cleaned the IAC?