1988 yj 2.5 TBI

this thing has been trouble free for a long time, now i have a problem i cant figure out.

it was pulled into the driveway a bit sluggish, so my wife left it and took the truck to work.

i went out to see what was wrong with it, assuming she ran it out of gas again.
it started right up for me, but the ildle roared to about 2800 and stayed there.

it appears that the Idle Speed Actuator (isa) is keepng it there.

i figure, pull the plug and it will let off, right? NO.
i commence to pulling plugs on the rest of the crap that is on the throttle body, and there is no change.
this damn thing still roars at 2800 rpm.

so i put them all back... no change.

any thoughts on this thing?
there are no vacuum leaks that i hear or see.

1988 yj 2.5 TBI

there are no vacuum leaks that i hear or see.

The leak is the only thing I can think of. I had a pickup that did the same thing. The only way I found the vacuum leak was with a spray bottle w/soapy water. Just a big enough crack in the hose to cause my problem.

my jeep did that after sitting awhile in a shop, probably with the ignition on since they were leak testing the arb. anyway, disconnected the battery to reset the computer and everything was fine. not sure if the 4cyl system is the same but it's worth a try. :2:

I don't know anything about TBI, but found this....hope it helps

http://www.affordable-fuel-injection.com/web/Troubleshooting%20your%20TBI%20Fuel%20Injection%20 System.pdf

Did you try my suggestion?

Did you try my suggestion?

i plugged and unplugged most of the wires under the hood. nothing yet.

Did you try my suggestion?

Top 3 Dukes69 suggestions:

3. Throttle cable could be stuck
2. Rev counter is broken
1. Try taking your foot off the gas