Hey, guys. I'm posting this on behalf of my brother, who has an '89 CHerokee Laredo, so obviously it's a Renix. Has a rather odd issue starting from a stop, and sometimes even a "California Roll". The engine wants to bog down and stall before suddenly, and quite harshly, picking back up and taking off.

Doesn't matter how much gas you give it, either. Has had a tuneup done recently, but with cheap Valucraft cap and rotor, so I'm very sure they're probably the problem. They have aluminum posts and I've read bad things about that. We have not done Cruiser's Tips yet, but will soon. Also steam cleaned the throttle body yesterday, so it's all nice and clean now instead of gummed up with ****.

I'm very sure it's the cap and rotor, but we could use some extra input. Runs fine going down the road, no bucking or anything that feels like a miss and cruises just fine. Gets up to speed just fine as well after it's little episode from a start. Hope you guys can provide some sound advice! Thanks!

 

Bump. Anybody?

 

Have you checked your fuel filter as well?

 

Not yet. Where would it be located?

 

Outside of the fuel tank. https://www.cherokeeforum.com/f2/fuel-filter-37690/
Look at post #6

 

Fuel filter is up on the rail near the tank, on the left. Trying to diagnose anything, especially Renix should start with checking/cleaning grounds. With the puter's and sensors doing random glitchs...well, you get the picture.

The IAC motor on the TB ether getting goofy commands, or sticking or failing might do something like you describe. Removing and cleaning it is something to do anyway, worth a shot, that.

 

Cleaned it while the TB was off getting cleaned as well. Is the Renix IAC testable, like taking it out and turning the key on? It should extend, right?

 

I don't know. (sounds right). I do know it will stay wherever it was when it was disconnected.

To do the sensor ground test you need a digital meter. Even the $5 ones at Harbor Freight will work, at least for a while! You can't get far with a Renix without one.

 

The TPS is moisture sensitive so it may be an issue with the steam clean that will potentially right itself when it has the chance to dry out completely. Letting the engine idle with the lid closed sometimes helps to expedite the drying process. The problem may very well be the budget cap and rotor but it's something else to consider.

 

Try going through cruisers tips first. Your Jeep will thank you. also, Thanks for Joining the service brother. (US Army 12N/Sapper here)

 

Agreed with F1, the tps does not like getting wet. Not sure here what all it has in it's bag of tricks. Anyway cleaning that gang of grounds on the dipstick stud is something anyone could start with. (Anyone who wants there ECU, TCU, and injectors grounded anyway)

 

TPS was taken off when the TB was steam cleaned and wasn't put back on until after it was completely dry. This has also been going on for a little while before it got cleaned anyway, but thanks for the advice! Really thinking it's the cap and rotor, so we'll get those replaced ASAP.

We will be getting on those tips probably tomorrow. I know the Jeep could really use it all....And my enlistment got set back a little. Weight issues came up, so Navy DEP dropped me. Going to the Army after I lose the 10 lbs I need to. Thank YOU for your service!