Jeep Grand Cherokee Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Ok, I have a 98 ZJ 4.0 4x4 laredo. I have been having some problems with the truck not starting after I drive for awhile. It starts perfectly fine in the morning or if I drive short distances. When I drive for awhile, say 15 miles or so, when I shut it off it doesn't wanna start for about 30-40 minutes. I've been trying to figure it all out but to no avail. I have replaced the crank sensor, cap, rotor, and coil. My plugs and wires are fine, I can hear the fuel pump pressurize and I'm kinda stuck on what else to do. I'm going to replace the pickup ecm today and see if that does anything. If you fellow keepers can help, I'd much appreciate it.
 

·
Registered
Joined
·
4 Posts
Does it not crank or does it crank and not start? The two first things i would look at if it cranks but doesnt start are 1) to see if the theft light is on and 2) if the check engine light comes on for a couple of seconds then goes back off (bulb check). If the theft light is off and the check engine light does it bulb check when you turn the key on then i would pull a spark plug wire off and check for spark. If you have spark then almost certainly the fuel injectors are fireing which would put you over to a fuel pressure issue. Of course this must be checked while the vehicle is having its starting issues. So you want to get it to not start then start checking it.
 

·
Registered
Joined
·
4 Posts
I would still check the theft light and the ckeck engine light. Then if you have a test light or even better, a volt meter, take the connector off the coil while it wont start and check the dark green and orange wire for power. There should be 12 volts key on and when cranking. One more thing to think about looking at is the cam sensor in the distributor. It is needed on start up for the computer to find #1 cylinder.
 

·
Registered
Joined
·
4 Posts
Ok. The fastest thing to do then is get a 194 bulb (like the ones used for the marker lights) unfold the electrical contacts so they are pointing stright down. Then it will look like a bulb with the bare wire sticking out the end. Unplug one fuel injector and put the bulb in the end of the connector (wiring harness side) and crank your jeep. You should see the bulb flash or pulse brighter then dimmer. Do that when it is having the starting issue. If that is fine then most likely you have a fuel pressure issue.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #7 ·
I haven't gotten around to testing everything, but I did replace the pickup. It still happened and I smelled fuel like I usually do
 
1 - 7 of 7 Posts
Top