Adin Kenneth Monroe

I have a 89 xj, renix motor unfortunately, but the other day it started to act a bit different. When I was driving all of a sudden I lost all throttle response, and it started to idle at 200-300rpms. Doesn’t always die but sounds like I put the worlds largest cam in. Curious what could cause that. And any solutions or tips to get this problem fixed! Thanks in advance

MaskedMallard

Are you able to open the hood and see if the throttle linkage is still attached?

Are you able to check the accelerator pedal to see if it moves the linkage under the hood?

cruiser54

Great place to start IMHO.

Adin Kenneth Monroe

Both the linkage is properly connected, and the pedal does move the throttle linkage.

MaskedMallard

This is what I would do. Pop the hood, disconnect the air intake to the throttle body. Check the linkage to make sure the butterfly opens. Start the Jeep and introduce some carb cleaner to the throttle body. Does it rev up? If so, it might be a fuel problem. Check fuel pressure with a known good gauge.

You could also pull the oxygen sensor out & rev the engine up, or disconnect the exhaust IN FRONT of the cataltic converter. You are looking for a plugged exhaust system.

Where you driving in the rain, mud puddles by any chance? You might have a failing ignition system component(s).

Adin Kenneth Monroe

I will definitely try that! Thank you! And I was driving in rain up a pass to get to the rocks on top.

MaskedMallard

If you suspect a failing ignition system, you can try this.
- in a dark area or at twilight/ night time, you can start the Jeep. Take a spray bottle and mist the sparkplug wires, sparkplug boots, distributor cap. You might see small sparks arching across to "ground". If you experience this, it's time to change your ignition system (distributor cap, ignition rotor, sparkplug wires, sparkplugs). DO NOT BE CHEAP. BUY QUALITY NAME BRAND REPLACEMENT PARTS.

- If you can't find a dark area, you can start the Jeep, and get your hands really wet. Then run your hands over the sparkplug wires. Be sure to keep your hands wet. I wouldn't really recommend this approach, because it could be a shocking experience with what you discover.

fb97xj1

I dont recommend that at all. Knew a guy years ago that did that during a downpour on the side of the road, and brushed his hand against the block. He jumped and cried like a baby. Said it was like getting hit by a truck, and his hand felt like it was stuck with a cattle prod. Couldnt move his arm or his fingers for a while.