97 ZJ 4.0 Died and Will not restart - Not sure it's the CKP
Since the CKP is a PITA to change no matter how you look at it, I'd rather not "just change it" without being reasonably sure it's the cause.
Wife was driving the ZJ yesterday in wet conditions. The rain had stopped, but we were getting local flash flooding -- so water intrusion is a possibility here.
Engine started sputtering and died over the course of about 5 seconds. After that, the engine would fire, run very very roughly for 2-5 seconds and die. Throttle input had no effect.
No Check engine light, no pending codes. As far as the PCM is concerned, nothing is wrong.
It gets fuel -- since it does fire a little -- you can also smell the raw fuel in the exhaust. So, this looks like an ignition issue to me.
I had read (somewhere) that when the CKP fails, you will get no fuel and no spark. Well, clearly, I am getting a little of both. Since the PCM shows no codes, I don't have a great starting point.
I had a screwdriver with me, so I pulled the distributor cap. It was dry in there. It looked like it was a bit worn down, but not enough to prevent it from running.
By the time I got home (on the tow truck) with the ZJ, the battery was dead from starting attempts. I put it on the charger and poked around a little bit, but go nowhere. Since it was getting late and the light was fading, I went inside to bed.
This morning, since the battery was fully charged, I cranked the engine over for at least 10 seconds, hoping that if a CKP code was going to show up, that it would. Still nothing. PCM is oblivious.
When I get home, I'm going to use my timing light to test for spark from the coil, and then on the output of the distributor. Since I know the injectors are firing (although maybe not at the right time) I know that I'm not having a fuel/injector issue.
I'd rather not just throw parts at a problem. Sometimes that's all you can do, but I'd prefer to exhaust the diagnostic tree first.
Could I have a bad cam sensor instead of a bad crank sensor? Possible coil failure? Distributor cap?
I found the ohmmeter test for the CKP; however, some people say that it can be bad and not show resistance -- so if I get resistance, it's definitely bad, and if not, it might be good -- and might not be.
What's the procedure to test the cam sensor?
We're going off-grid and moving to Texas! -- http://www.theratracelosers.com/
Check out our YouTube Channel! http://youtube.com/user/theratracelosers/