Sometimes my 89jeep cherokee wont start, but when i pop the hood and unplug and then replug a three prong connector towards the back of the motor by the valve cover,it starts right up???Does anyone else have this problem???

Thanks!!!!

 

You're gonna have to be more descriptive of the plug and where it is...

When you say 'not starting', is the starter not turning the motor over, or is it and it's just not firing?

 

crank sensor (cps) ??

 

the little 3 prong connector i believe you are referring to is your crank position sensor. it is either loose or going out. all it is, is a magnet that tells the computer where the crank is positioned at (hence CPS). it is on the top driverside half of the transmission bell housing and is a ***** and a half to get to while the tranny is in the car. but that is the only 3 prong connector i can think of...right behind the throttle body.

 

Rear of intake manifold, driver's side of valve cover? Three-pole connector with two wires?

And it will "Crank, Not Start" until you wipe the plug?

Replace your CranKshaft Position sensor (CKP) - they tend to go out after a while, and when you unplug and replug the connector, you wipe the contacts and make it afresh. You can try disassembling the socket and cleaning it (mild abrasive to remove oxidation - jeweler's rouge or cheap toothpaste and an old toothbrush, rinse well, reassemble,) but you'll probably have to replace the thing anyhow.

And it really does help to be more descriptive of your "No Start" condition, and provide a picture of any object of interest if at all possible (so we don't have to guess.) Possible "No Start" conditions include:

- No Crank.
- Crank, No Start (doesn't try to "catch")
- Crank, No Start (tries to "catch," but won't try to run)
- Crank, Start, No Idle (catches, but stalls when you let off the key)
- Crank, Start, Runs at Part Throttle Only (won't stay running unless you're tapping the accelerator slightly)

And those are just the five most common. All have different causes, and some have several possible causes each.

We really do want to help - but if you want us to help you without being there at the vehicle, we need for you to give us as much information as you possibly can!

Oh - and your 89 is a "RENIX-era" Jeep - 1991-up parts will not work on it. I'm sure you can still get the RENIX CKP at the dealership, you can probably get it in the aftermarket from BorgWarner, and I'm sure you can get it at any local Crown Automotive distributor (or mail-order from Morris 4x4 Center.) If the sensor fails totally, you'll have a "Crank, No Start" - as that sensor is used to generate timing data for ignition and fuel injection events.