help!!!! 96 Xj wont start

[kirkandsylvia]

Is it just me...... I'm dying to know what will get this Jeep to start. It's turning into a movie and I've got to know how it ends. Don't leave us hanging. Make sure you give us details of what was the problem.

I agree.....a really bad bad.....bad movie...one in which has cost me more than 400 bucks...and still no start. If this were a "first date" movie, I'd shoot the date, bury the jeep and move on to something more simple like under water basket weaving. I will keep all you day time soap opera people updated. As we say at work, "as the antennas of NASA spin"

[6spdYJ]

Have you pulled a plug and laid it on the block while someone tried to start it? Spark or no spark would be easy to determine. Also, see if the plug hole mists out gas vapor (just disconnect the pulled plug wire at the cap first). Have you tried checking to see if you get power to the 30A fuse that feeds the ASD and fuel pump relays? If the fuse is good but not getting power, you ain't runnin no matter what. If by chance you do have spark but no fuel, it is possible you lost the cam drive sprocket. No cam tuning means no valves opening or closing.
I've also seen a cam grind itself flat. It was weird. The motor ran strong until one day it was shut off and wouldn't start again. Wasn't until I pulled the valve cover to see the rockers barely getting nudged.

[inVERt'D]

There's no spark, correct?

If there's fuel and spark but no start, then I'd be suspecting compression, which as Ted mentioned could be caused by the valve timing chain slipping. They do "stretch."

Awhile back a friend's car broke down at the gas station. I popped the hood and what a mess. The only thing that wasn't shot was the air filter. Spark plugs were swimming in oil, were fouled, and worn out. Very weak spark. Not a lot of fuel pressure at the schrader valve--fuel kinda oozed out. Replaced and gapped spark plugs, replaced fuel filter. Now I had decent spark and fuel pressure but no start. It did, however backfire through the intake once or twice. Pulled the timing cover, and sure enough, the belt was completely stripped of teeth at the crank. Fortunately it was a non-interfering engine, so the valves and pistons were fine, and I was able to fix it. Funny thing about it is that it was a wonder the car still ran when the timing belt failed.

[kirkandsylvia]

There's no spark, correct?

If there's fuel and spark but no start, then I'd be suspecting compression, which as Ted mentioned could be caused by the valve timing chain slipping. They do "stretch."

Awhile back a friend's car broke down at the gas station. I popped the hood and what a mess. The only thing that wasn't shot was the air filter. Spark plugs were swimming in oil, were fouled, and worn out. Very weak spark. Not a lot of fuel pressure at the schrader valve--fuel kinda oozed out. Replaced and gapped spark plugs, replaced fuel filter. Now I had decent spark and fuel pressure but no start. It did, however backfire through the intake once or twice. Pulled the timing cover, and sure enough, the belt was completely stripped of teeth at the crank. Fortunately it was a non-interfering engine, so the valves and pistons were fine, and I was able to fix it. Funny thing about it is that it was a wonder the car still ran when the timing belt failed.

I did pull plug and ground it out while starting....no spark...pulled coil wire out of cap just far enough to see if I get a spark there.....nothing.....as far as cam flattening lobes or cam gear or chain breaking....the engine still turns over and sounds the same as always nd with the plug out checking for spark....I had a compression gauge on that cylinder and it was 145. Check all cylinders and the lowest one was at 138 and a high of 148. Cam is turning and valves are opening and closing. I haven't had time because of busy schedule at work to check ASD relay, although since I'm out as of today on a work injury, I should have time to check that. This problem is tied into electrical....some how some way. It would be very shocking to find a non electrical cause to it not starting.

[Lumpy Grits]

Again, try this.....Run a lead from Bat+ to Coil+ and try starting.
LG

[kirkandsylvia]

Again, try this.....Run a lead from Bat+ to Coil+ and try starting.
LG

Ok.....I put 12 POS to the coil and also verified the negative to the coil back to negative post on the battery with a meter. Tried starting and nothing. I checked the ASD relay. With key in run position I pulled the ASD relay and can hear it click. I checked at ASD terminal and see 2 point that have 12 volts....point 3 and I think 2. When I tried starting it..I also shot some starter fluid but again....no start. The drama continues.

[Russ Chung]

Ok.....I put 12 POS to the coil and also verified the negative to the coil back to negative post on the battery with a meter. Tried starting and nothing. I checked the ASD relay. With key in run position I pulled the ASD relay and can hear it click. I checked at ASD terminal and see 2 point that have 12 volts....point 3 and I think 2. When I tried starting it..I also shot some starter fluid but again....no start. The drama continues.

In order to get a spark from the coil, you should have 12 volts at the positive primary terminal (which you have). Then, the computer will alternately open and ground the negative terminal in order to energize and then collapse the primary field of the coil. It is the alternate energizing and collapsing of the primary field which generates the spark. If the voltage at the negative primary terminal of the coil doesn't change, then
1. The wire between the computer and the negative terminal of the coil is bad (open or shorted),
2. The computer is bad (but you said in a previous post that you changed it),
3. The pickup coil in the distributor, which feeds the timing signal to the computer, is bad.
4. The crank position sensor on the bell housing, which also feeds a timing signal to the computer, is bad (but you said in a previous post that you have changed it).

I found the wiring diagram for your 96 Cherokee on the AutoZone web site. It's diagram #41 (you might have to register in order to see the diagram):
http://www.autozone.com/autozone/rep...00c152800a9de9

[Lumpy Grits]

Dizzy is dead.
LG

[kirkandsylvia]

[QUOTE=Russ Chung;221946]In order to get a spark from the coil, you should have 12 volts at the positive primary terminal (which you have). Then, the computer will alternately open and ground the negative terminal in order to energize and then collapse the primary field of the coil. It is the alternate energizing and collapsing of the primary field which generates the spark. If the voltage at the negative primary terminal of the coil doesn't change, then
1. The wire between the computer and the negative terminal of the coil is bad (open or shorted),
2. The computer is bad (but you said in a previous post that you changOked it),
3. The pickup coil in the distributor, which feeds the timing signal to the computer, is bad.[/QUOTE


Ok Russ....its starting to make sense. I did change the computer.....and I also change the pickup in the distributor....at least thats what I think it is. Its a flat plastic disc with a 3 lead wire harness coming off of it that has a space between a sensor and i think a magnet that a half moon metal flange attached to the distributor shaft and spins through the pickup....right. if so....thats new also. I checked the negative terminal of coil to the negative side of battery with a meter and got continuity without turning over the motor. So what you are saying is I shouldn't see a closed circuit there as the computer should be opening and closing that negative....right?

[Russ Chung]

...So what you are saying is I shouldn't see a closed circuit there as the computer should be opening and closing that negative....right?

Yes, the computer should alternately open and close the circuit through the primary windings of the coil in order to generate the spark. When the key is on, the positive terminal on the coil should have 12 volts positive. And when the engine is turning over, the negative post should be alternately open and grounded. I don't know if your voltmeter would be able to show the fluctuation in voltage as the computer opens and closes the circuit. If you have a dwell meter or a dwell setting on a multimeter, it should show.

If the primary circuit does not alternately get energized then collapse, it could be the wire to the computer, the computer itself, or one of the sensors that feeds the timing signal to the computer. Since you have changed the computer and the sensors, I would guess that the culprit is an open or a short in one of the wires between the computer, the coil, or the sensors.

[karstic]

It still may be a bad CPS.

The Autozone CPS have been known to be faulty brand new out of the box.

http://www.jeepforum.com/forum/f11/h...0/#post4196472

Post #2 in the above thread details how to test the CPS

Some more good info on a no-start

http://www.jeepforum.com/forum/f11/h...-4-0-a-803463/

[Zoobi]

Make sure there isn't an anti theft system under the dash. Disabled or not those still have a way to interfere. If you have one remove it completely. You can always put it back later. You would be surprised how many people have these things installed from the dealer than "bypassed" then fail down the road. Most were tied into the starter, some were tied into the ignition. Some of the ones I dealt with were unscrewed and stuffed up under the dash so you couldnt see it.

Scott

[Jason]

Make sure there isn't an anti theft system under the dash. Disabled or not those still have a way to interfere. If you have one remove it completely. You can always put it back later. You would be surprised how many people have these things installed from the dealer than "bypassed" then fail down the road. Most were tied into the starter, some were tied into the ignition. Some of the ones I dealt with were unscrewed and stuffed up under the dash so you couldnt see it.

Scott

X2! Ask me how I know. My electrical gremlins were a result of a factory added ignition kill switch that had failed. Good luck. I remember that feeling of wanting to burn my YJ alive and put it out of it's misery. Do be careful about just throwing money at it for new what you think are bad parts. I saved the ones I had replaced as spares since they were never the problem.

[Lumpy Grits]

It still may be a bad CPS.

The Autozone CPS have been known to be faulty brand new out of the box.

http://www.jeepforum.com/forum/f11/h...0/#post4196472

Post #2 in the above thread details how to test the CPS

Some more good info on a no-start

http://www.jeepforum.com/forum/f11/h...-4-0-a-803463/

There is a reason why 'pros' buy from NAPA .
LG

[inVERt'D]

There is a reason why 'pros' buy from NAPA .
LG

A long time ago the regulator on my little commuter car died. Kragen was nearby and open, so I drove down there (in my pickup) and bought a new, solid state regulator. Long story short, I tried three of those POS Kragen regulators, and none of them worked. I ended up getting one at the junkyard and never had another regulator problem. Kragen had a reputation for crap electrical parts, and I found out why. Never again bought anything at Kragen besides cleaners and towels.