Curt

1999 Cherokee Sport 4.0 I6. I have the following problems:

1. Most times from cold (sat overnight) start, I can drive 200 yards and will have hesitation similar to a fuel cut in other vehicles. A pop from what sounds like the throttle body and a surge of power. This may happen several times. Giving more throttle alleviates the issue. Sometimes it requires a few attempts but then the vehicle drives normally.
2. Driving at any temp, experience inconsistent speed. The vehicle is "surging" as if you were giving it throttle and releasing rapidly. It will recover and drive as normal.
3. Rough idle intermittently. Rough is a kind word for it. The vehicle will shake hard. I assume the ECU is regulating the input and during these times will try to give it a throttle bump to keep from stalling out periodically.
4. Rough idle comes and goes whether running or parked for 10 minutes running the whole time.
5. Stalling - This doesn't feel like it's stalling as in if there was a reduction in fuel or air. This stall is a cut as if the auto-shutoff was triggered. Sometimes the engine will start right back up immediately and drive as normal. Sometimes it can take an hour or more for it to start again. In extended cases, the hood is opened immediately to alleviate any over-heating concerns to whatever components might be suspect. This issue has caused me to be stranded several times.
6. Downstream sensor is currently missing.
7. Horn suddenly stopped working recently as well. I'll withhold why I think that may be related to see what others think.

Thus far, I've done the following:
1. Replaced the IAC. Old one was clearly clogged was not coming clean.
2. Replaced plugs.
3. Replaced wires.
4. Replaced Cap & Rotor
5. Replaced Ignition Coil
6. Rewired ground G101 as a result of #5.
7. Carefully inspected throttle body & connections.

Soon to replace will be the TPS and CPS.

I have another electrical issues stemming from F16 in the PDC that correlates to G107 I think. That particular part seems to be isolated from all of these components however it does mean that I don't have working gauges (or radio).

Any help will be greatly appreciated! I'm not a stranger to cars. I own a Fiero which I've managed to keep running for years as well as rebuilt a few engines, etc. I'm just out of time and need answers faster than I can test and ferret out the cause.

If you need pictures, I can provide them.

cruiser54

Have you cleaned the throttle body?