I have an 87 cherokee w/the 4.0 and it doesn't want to run sometimes and other times it runs great....I have no idea what to look at first...is there some common flaw on this year model that will make it do this?

 

Now what do you mean does not want to run? Will it just crank and crank and crank and not start? or do nothing at all, such as maybe an issue with the battery?

 

Sorry about that, it will just crank and crank.....then a few days later it may crank and run for a week perfectly, then do it again intermittently. I would think a short or something....but I just have no idea where to start.

 

First things I would check are fuel and spark. Those times it wont start, I would listen for the fuel pump to engage. I would also check the distributor cap and rotor. If there is corrosion on the connections that could cause it not to start. If its neither of those I would then look into sensors, CPS, Camshaft position sensor in the distributor. It could also be a bad ground.

 

I have an 87 and had this exact issue. My problem was my crank position sensor.. really easy to change too and I think it cost around 40 bucks

 

Really that cheap? A new one for me from the auto parts store was like $94. But yeah they are not hard to change at all.