Running great...and then!!!

[cigarluvr]

1993 ZJ with 4.6L running great, no hiccups, no sputters, couldn't be better, put about 150 miles on it so far. Then yesterday went out to start it and nothing! Just turns over without the hint of firing. Checked to see if there were any codes (OBD1), blasted MAP (13, 14) codes again. Checked the wiring to the ADJ MAP...looks good. Could the MAP crapped itself? Am I missing anything. Frustrating because she was running like a BEAST!

[604rail_king]

Checked to see if you have fuel pressure?

[cigarluvr]

Plenty of that...shot it half way across the neighborhood...lol...

[cigarluvr]

OK...went out and checked pressures and voltages and spark...BTW its 15* and blowing 20 mph here in Alaska today, oh and she had to break in front of the garage backed in...can't even winch her in...lol.

42psig at the rail...

5.05v at the MAP...

NO SPARK! CPS maybe? Do they just crap themselves like that? Of course its the only sensor I didn't swap out.

[Muad'Dib]

Yes.. usually caused by crank position sensor.

[cigarluvr]

Poo...i was really enjoying smoking my 33s...lol...ok, just once.

Heres where living on an island sucks! 3 days for NAPA to get the part or 5 for amazon! Oh well, she still looks good in the driveway...

Lesson learned? CHANGE THE STUPID CPS WHENEVER IT HAS 244K MILES ON IT IF YOU ARE PUTTING IN A NEW ENGINE!!! blah!!!

[cruiser54]

Sure the CPS wiring just didn't get toasted on the exhaust manifold?

[SilverXJ]

I would say CPS as well if there is no spark. As cruiser said, check the wiring too. I also have heard that unplugging the CPS sensor then plugging it back in helps.

[racing89]

Check for injecter pulse 1st. Then you can suspect cps if you have neither fire or injecter pulse. If its just spark your lacking then you check for ignition power to the coil and signal. The dodge coil your running, does crap out commonly. If your coil has fire and your plugs dont, the rotor or cap is to blame . No-go 101

[cigarluvr]

How exactly does one check injector pulse?

[cigarluvr]

Silver,

Tried that...no-go...

[SilverXJ]

Use a noid light to check the pulse. You unplug the injector and plug the light in its place. You could also fab something up using a small bulb.

[cigarluvr]

So I have yet to be able to check injector pulse. I did however change the CPS. And guess what? Nothing, same condition persists. Crank with no hint of firing. Haven't actually been able to check spark (hard to do alone). Hopefully when the wife gets home I'll check for spark and let y'all know. I really appreciate the help so far.

[gradon]

Crankshaft position sensor would be the first suspect, then the ignition coil.

[cigarluvr]

Well, nothing like a little shotgun troubleshooting... Boggles my mind on how I can work on multi-million dollar aircraft but a simple Jeep gets the best of me...

Anyway, ended up being the brand new MSD Coil. Threw in a spare and fired right up. At least I can say I have a road spare for my CSP Sensor. Thanks for the guidance guys!