It just keeps cranking but wont start? I changed the batter cables, new spark plugs, new spark plug wires, new distrubtor, new rotor, new cap, and new alternator. I had the starter tested and it was good. People are telling me it could be the crankshaft postion sensor or neutral start/back-up light switch? Any ideas?

 

if its cranking the starter and neutral safety switch are good. The crankshaft position sensor is a common one, I had a coil go bad once too though.

 

Replace the CPS.

 

Do you know if your getting spark and injector pulse? if neither replace your CPS.

 

i had the same problem with my 96 in would crank over but it seemed like it was not getting gas but there was gas in the fuel rail, so me and my brother looked at it for hours and found that there was no power to the coil, so then i brought it to a dealer and they found it was the ASD (automatic shut down) relay in the fuse box under the hood so they replaced that and the 30AMP ignition fuse and she was up and running like a champ
this could be something for you to look at the fuse is like 13 bucks or somthing
hope this helped

 

there is no ASD in a 1989 cherokee, in any case the ignition fuse is worth a check...

 

Welcome!
Did you check for spark? If not check for spark at a plug. If you don't have spark, I would go to the CPS first. This is most likely the problem.

 

is your check engine light on..if it is then go to an autozone and they will run the codes for free..but i would change the crank positioning sensor because that is a common thing and they are only around $30

 

no check engine light or codes in a 1989 cherokee...

 

When I went to test drive the 90 I just bought, it started and ran great, got it back to the guys house and told him it seemed to thunk when it shifted and he said well let me see. He jumped in and it would not start, bad coil. Put a new one in and life is good.

 

I forgot to tell you I have a new coil in there too. My dad is coming over friday to try the crankshaft postion sensor and hopefully thats what it is. I will let you guys know what happens when I do it tomorrow!!

 

You will need a 8mm wrench and i suggest you remove the front drive shaft to have access more easily.

 

is there a way to do it without removing the front drive shaft?

 

you can do it but you will get your arm stuck in there and swear...

 

i was trying to look driveshaft up in my chilton book but couldnt find, what other would they call it?