Please help!!!

I have a 94 cherokee, it runs great for about 15 miles then dies. You can start it again and it stays running as long as you keep the rpm's above 1100 otherwise it dies and wont start again for about an hour. What's wrong with it?

Dying out after a few minutes makes me think it's the Crankshaft Position Sensor.

Keeping the rpm's up makes me think of plugs, cap, rotor and wires. When's the last time you replaced these?

Thank you for your help. We have not had this jeep very long, so we have not replaced any of those iteams yet. We have been looking to see what others have said on the internet and it has been interesting to say the least.

The 4.0 is sensitive to tune up items, so please post back after you`ve put in new plugs, cap and rotor. Since you bought it used and can`t know what the previous owners did maintenance wise, I`d also make sure to replace the plug wires.