No start ? on 92 YJ 4.0l

[ChiXJeff]

A friend of mine has a 92 YJ with a 4.0l that is dead.

His wife parked it one night, and it hasn't started since. He's getting spark (checked by pulling a spark plug out and grounding it) and is getting fuel (checked the injectors with a noid light and the gas fumes out of the spark plug hole.) Distributor is new, with a new coil and a new battery. Crank speed is a little slow, but it does turn over.

It's done something like this in the past, but it's always fired back up after a couple of hours. Now, it just turns over, and isn't firing on any cylinders

Any suggestions?

 

[92stroker]

Is it an automatic? If so it could be the neutral safety switch. Sometimes they will still start if you put them in neutral. You can also move the gear selector back and forth a few times and get it to start. To bypass the switch, disconnect the neutral safety switch pig tail and on the engine side of the wiring harness put a jumper between pins B and C. If it starts with the jumper in it is a problem with the switch. The most common problem is it needs to be adjusted. The second most common is it is full of crud. The switch can be removed and cleaned. PLEASE be very careful removing it. The arm inside is very fragile and if it breaks the unit will need to be replaced. New they are about $300.00! They are also hard to find used in good condition.
If this appears to be your problem, let me know and I can provide detailed instructions and documentation.
Send me a PM.

 

[ChiXJeff]

Whoops...... no, it's a stick. And won't the NSS stop it from cranking at all?

 

[RichP]

Try a coil. When they go bad they can still spark. Not real familiar with the 92's but our 89YJ had a bad ECU, it was under the radiator overflow on the drivers side rear fender. We had it tested at AA and bought a new one, fired right up.

 

[ChiXJeff]

<grin> As noted above, it does have a new coil.

ECU? As in Engine Control Unit? Sounds like a computer, and expensive.