Starts on and off

[Countrygalnlv]

I have an 1989 cherokee straight 6 4.0 last couple weeks has been giveing me troubles starting pop the hood wiggle the plug wires and make sure they are all tight and it starts so we changed all the plugs but still haveing a problem then yesterday hooked it up to a battery charger started right up.

My plan today is to change the plug wires, cap, roter, thermostat(was over heating took thermostat out a month or so ago and just got a new one), and battery.

I need to know if this doesnt work what my other possible problems can be. As detialed as possible since I have no choice but to do the work myself liveing over seas and the mechnics pices are outragious (eg: $3000.00) to change rear main seal.

Thanks

[Saudade]

Once it starts, does it run OK? Once it's hot, does it start right up? If it doesn't start on it's own, does it start with a jump (besides the time you posted)?

Changing the rear main seal is not too difficult (just messy). I did mine in my garage with just a few hand tools.

http://jeepin.com/features/rearmain/index.asp

[Countrygalnlv]

Once it starts it runs fine, there is no real specific time when it wont start hot vs. cold and it always turns over but will not start and has never had to be jumped except the time we put it on the charger.

[Countrygalnlv]

Also can someone tell me does the 1989 chrokee have points? I was told yes but cant find them in the chiliton manual

[Saudade]

It does not. It's electronic ignition and electronic fule injection. It's important to determine if, when it doesn't start, is it a fuel problem or an electrical problem.

There are a number of sensors that control both ignition and fuel delivery. A common problem is a failing Crankshaft Position Sensor (CPS). If it's bad or intermittent, it would prevent the car from starting (no spark) but would also cause the engine to quit when running.

On my '88, I found a number of connectors to these sensors that had some corrosion. You may want to disconnect them to inspect them and clean as needed.

[Countrygalnlv]

I doubt its a fuel problem about 2-2.5 yrs ago I replaced all fule injectors, fule pump, fule presure regulator, and fule filter I dont think theres anything left of the fuel system.

I hasnt quit running only problem is wont start cold or warm doesnt matter it starts when it wants to.

[Dale Aeppli]

Originally Posted by Countrygalnlv

I doubt its a fuel problem about 2-2.5 yrs ago I replaced all fule injectors, fule pump, fule presure regulator, and fule filter I dont think theres anything left of the fuel system.

I hasnt quit running only problem is wont start cold or warm doesnt matter it starts when it wants to.

Can you hear the fuel pump click when you turn key on. Try turning key on and waiting 15-30 seconds and then try starting. If it starts this way the fuel pressure is leaking and looseing prime. dale
[email protected]

[Countrygalnlv]

Ok so I changed the plug wires, cap, and rotator, put a new battery in it and still nothing. Do fule pumps really go bad taht fast?

[Saudade]

Are you getting spark at the plugs? Also, put a fuel pressure gauge on the port on the fuel rail and see what pressure you get with the key on (not running).

Also try the other "usual suspects". Move the shifter around to see if it's a bad Neutral Safety Switch.

[Ironic]

You mentioned that it overheated, having the 89 as you do I know how them "expansion" bottles manage to spray all over the place. If the problem is intermitant- clean up any electrical connecters that are within reach. If the engine cranks you ruled out the starter, and neutral safty switch. If it cranks but won't start determine whether you have spark and fuel.

[Countrygalnlv]

OK Im pretty sure now that it is the fule pump since I no longer here that nice hum the fule pump makes when the key is in the start position. Now my question is, is it possible that its a fues??? Please tell me its possible its a fues because I hate the though of changeing that pump again. If it is a fues can someone tell me which fuse box its in? I read the chilton but it doesnt mention a fuse for fuel pump.

Thanks

[89ltd]

on the passenger side there are four relays, the fuel pump relay is the third from the fire wall. You could try that, also, power going to the relay is supplied from the starter relay through a fusable link

[Countrygalnlv]

Great!! thanks!! Sounds so much easier than changeing the damn fuel pump again. That was a major pain.