4.0 will crank but not start

babybrudder · 02-09-2010, 08:59 AM

2000 4.0....parked the other night after work and was running fine, next morning engine turns over but will not start. i tryed putting gasoline directly into intake with same result so i eliminated fuel relay, fuel pump (fuel rail is pressuring up)

have not had time to run diagnostics yet. hopefully my son will bring the computer by this afternoon.

**Wheelin98TJ** · 02-09-2010, 09:22 AM

There are 2 common causes of no spark in the 4.0 I6:

Cam position sensor
Crank position sensor

Here's how to test the crank position sensor:

Crank Position Sensor - How to test

The cam position sensor should fluctuate between 1-5 volts while cranking.

babybrudder · 02-09-2010, 09:34 AM

thanx for the info, ill get started on this this afternoon and see how it goes. ill keep ya posted as to the outcome.

babybrudder · 02-17-2010, 09:44 AM

crank position sensor was the problem...something sheared the wires off....new sensor and she started right up, thanx for the help.

02-09-2010, 09:34 AM	#3
babybrudder Registered User Join Date: Feb 2010 Location: corpus christi,texas Posts: 9 Profile Gallery Classifieds My Jeeps	thanx for the info, ill get started on this this afternoon and see how it goes. ill keep ya posted as to the outcome.

02-17-2010, 09:44 AM	#4
babybrudder Registered User Join Date: Feb 2010 Location: corpus christi,texas Posts: 9 Profile Gallery Classifieds My Jeeps	crank position sensor was the problem...something sheared the wires off....new sensor and she started right up, thanx for the help.