Awkward Idle

I have a 1986 2.5 liter TBI engine with a 4 speed and it ever so often idles very sparatically. The engine will sometimes die when coming to a stop or after I've revved the motor while not moving. This only happens sometimes. Weather nor engine temp seems to affect any of these problems. My idle will sometimes idle normal then drop down to the point where it feels as if it going to die but doesnt and goes back up to normal. I have replaced the fuel pump, spark plugs, plug wires, disp. rotor and cap and put BG44K through the tank. Any info on what this would be very appreciated.



Thank Art

Low Idle

Sounds like the EGR. Both the 4.0 6 cylinder and the 2.5 4 cylinder use an EGR in the pre-HO years. If the EGR fails, then you get a continuous supply of exhaust recirculated into the intake--results in very low idle or possibly stall, but works OK at higher engine speeds. The test is to unplug the vacuum line going to the EGR, and seal the line with a screw/plug/golf tee. If the problem goes away, then the problem is the EGR. It sounds like yours is sticking- intermittent problem. They are easy to replace. On the 4.0, removing the airbox gives reasonable access....sorry I don't know the 2.5 engine. My 1990 with 4.0 engine is on its third EGR since new, and my daughter's 1990 4.0 currently has the EGR vacuum line pulled as it waits for a new EGR. 4xBob

4XBOB, Thanx for the info. I'll try that this weekend and let ya know if it works.

Thanx again, Art

4XBOB, I replaced the EGR valve last nite, now the beast runs like it did years ago. Thanx for taking the time to help a fellow jeeper.

Thanx Art