Unusual Starting Problem - Tried Search

Hey All:

I've got a 90 Limited (RENIX) with an unusual problem - sometimes it'll start, sometimes it won't - it'll just crank and crank until I kill the battery.

Now, it's not unusual for an older XJ to have a starting problem - but this is: When the Jeep won't start, if I pull the fuel pump relay and have someone turn it over, it'll start right up. Of course, have to plug back in the relay immediately or the Jeep will die.

I've replaced the fuel pump, filter, and regulator. I've also checked the CPS (240 Ohms) and the plugs, cap, and rotor. I also searched around the engine for loose wiring or connectors, vacumm lines, etc. with and didn't find anything out of the ordinary.

Any ideas?

Thanks,
Chris

My 89 does the same thing. On the right side (drivers side) back by the firewall there is a senser in the intake manifold. Unplug/plug the quick connect for the sensor three times and then it should start right up.

Mine does the same...most times it starts great but once and a while it just turns, turns and turns and does not kick in.

If I unplug/re-plug the Map Sensor with the ignition on - as mentioned above - it starts the next time I turn the key.

How do I fix this?

Is it the Map Sensor or something else?

Best,

John V.

89' XJ 4L Auto

http://www.jeepsunlimited.com/forums/showthread.php?s=&postid=4757303#post4757303

I'm haveing similar problems