I gave a guy a jump start this a.m...2 minutes later and 1/4 mile down the road she died...now it cranks really good but will not start...currently sitting in a Home Depot parking lot.

A month ago it would not start in the a.m...cranked really good but would not start...afternoon after sitting all day...fired right up.

I have done some checking. Here there was an older thread with similar characteristics. The CPS keeps coming up in each conversation as well as the '98 not having a CPS.

Question: Does this sound like the CPS, and does my '98 have a CPS? This is a diagram I found in the older thread...

 

The 98 has a cps cause mine went bad and did the same thing yours is doing but mine stalled in the highway so it was not fun she then cranked but no start so you might want to check it

 

I agree with the cps


they are not a lot of money, id replace it anyway...to rule it out down the road

 

All 4.0 engines have a crankshaft position sensor AND a camshaft position sensor. So need to differentiate. The diagram you show is of the camshaft position sensor.

The sensor more likely to be your problem would be the "crankshaft position sensor". Located on the transmission bellhousing.

But don't get too far ahead of yourself or guess. Some basic testing is in order. First test for spark. Pull a plug. Keep it attached to the plug wire. Place the plug electrode near a good engine ground. Have a buddy crank the engine over while you watch. You are looking fora strong, BLUE, snapping spark. Weak spark may indicate a faulty ignition coil.

IF you have good spark (and only if) then introduce a small amount of gas into the intake. If the engine starts and runs for a few seconds, you have identified a "fuel delivery" problem.

The above quick and dirty tests take only a few minutes and go a long ways in determining root cause. If the crank sensor is truly bad, you will have no spark and you will have no fuel going TO the fuel injectors.

Good luck and keep us updated!

 

I finally got my '98 back on the road. Crank sensor ($86 @ Autozone and only ask once if it was a Grand Cherokee).

Rained all last week here in NE IL and only had one clear time on Thursday night to try. Didn't get it. Today I needed to let down the front drive shaft and the shift bracket to have plenty of room. 10 minutes later she fired right up.

Thanks for everyone's input.