94' Jeep Grand Cherokee Limted 5.2L V8 - will not start to save my life

also do the test caddyman recommended

Did the test that caddyman suggested and there didn’t look like any slack between the crank and rotor rotation.

I just changed out the PCM with one from the pick n pull lot, but the best I get is a little more get up and go. Still just cranking and not fire up. There is a a “lump” sound coming from the front if the engine now along with the smell if fuel from the tail pipe. I’m turning it over a lot, but apparently enough. The sound is like if you’re turning a crank then you hit the bottom of the revolution you’d come down hard.

While we’re thinking, pull all the plugs and let the cylinders dry out. I’m guessing the engine’s pretty flooded by now. BTW, how do the plugs look?

I’m confused by the alternator code. If the engine cranks ok, the battery must be charged ok, and the only way it got charged is a working alternator. It’s possible I guess the field coil just recently shorted out, and that’s what is causing both the code and the ignition problem.

On some cars it is possible to completely disconnect the alternator and the engine will still start and run for a few minutes at least, until the battery discharges. It’s also possible running the engine with the alternator disconnected could cause some other problem, perhaps expensive. I don’t know. In theory at least – while the engine should never be allowed to run with the battery disconnected – it should be possible to start and run the engine with the alternator disconnected. Maybe someone here knows if it is ok to start and run your engine with the alternator connector disconnected. If so, that could be used to eliminate the alternator as the problem.

What I think has happened is you got something in the high voltage system wet by spraying the radiator with the hose, which prevented a good spark. And then each time you tried cranking it to start the engine, since you had no spark, all that happened is more fuel got injected into the cylinders. And now they are so full of gasoline it wont start no matter how good the spark is. This same thing happened to me with my old VW Rabbit, and the only solution was to remove all the spark plugs wait for a few days to let the gas evaporate from the cylinders. So were I in this situation I’d remove all the spark plugs and wait for a few days before assuming the problem is anything other than that.

hang in there…

Yeah, the plugs are reeking with petrol, I figured that if I’m smelling fuel id done something like flood it.

Though even with the plugs flooded shouldn’t I see spark when I have a plug out and looking for it?

I checked the top of the coil while the ignition was on and with 10 volts coming from the battery I’m getting 3 volts at the top of the coil. Have the battery on a trickle charge cause it’s been a week almost of this.

The alternator code vanished as well. Just something to scare me even more.
Still confused by the voltage readings coming back from the new sensor of the crankshaft.

please leave the electric alone until the gas smell goes away,

“…shouldn’t I see spark when I have a plug out and looking for it?”

Yes. You might as well leave the plugs out until you can see that spark.

I’m determined, but I try not to fall off the fence and smack my head on stubborn!! I’m going to let her sit for a while and then see where it goes from there.

Learning something new everyday. Appreciate the lessons everyone has offered. .

I wear the heaviest gloves I have when holding a plug against the head or exhaust manifold to look for sparks.

The negative side of the ignition coil should be triggered ground by the PCM. Your seeing 3 volts may be the average voltage if your meter is slow.

Have you observed the ignition coil while cranking the engine? If it got wet when you rinsed off the water pump this may have finished off an old coil wire. Look closely for spark jumping to ground.

I’m going to proceed tomorrow with getting new plugs and letting the fuel evaporate from the engine. A few of the plugs look a bit worn, beyond the normal wear. Then I’ll go about testing for spark at the coil and the plugs.

Would I be correct to disable to fuel injection system while testing to prevent the flooding that is now present?

If you have no spark it could also be the distributor pickup coil.

You should see at least 10 volts going to the PLUS side of the coil while cranking the engine. If you don’t have that much then try jumping 12 volts to the PLUS connection. That should get the ignition going. If the ignition is working you should be able to place a test light probe tip on the minus side of the coil and see flashes as the cylinders fire. Since the cylinders were wet that means the injectors are working. So you have ignition, timing, and valve timing (compression) left. I doubt the PCM is bad but that is possible.

“Would I be correct to disable to fuel injection system while testing to prevent the flooding that is now present?”

I would say yes. Pulling the fuel pump relay might be the easiest way.

Okay, so I picked up both a crankshaft sensor and an ignition coil. You can burn me at the stake, but picked up the sensor at the pick n pull. Also picked up a “fancy” spark plug tester. Something easier to us than a bolt and asking my roommate “here could you hold this for a sec…”

The other sensor was not getting voltage back from it and it was an aftermarket auto part stores version. The one from the salvage came off another dodge 318 motor.

Still no spark after replacing it. So replaced the ignition coil. And let there be light!!!

Plugged the fuel injector back in, a lot of hesitation and then vroom! Now charging the battery back up and then I’ll crank it over again. New plugs as well.

Oh and it started back up again…

Thank you to everyone for the info on testing the timing, the electrical and experiences of prior problems.

yeah, when I heard the coil suggested I felt stupid for not thinking of it myself. doh!

I hope that you ll remain on the forum. you seem to fit right in

wes

Glad you got your vehicle back on the road. Good for you for sticking with it.

Thanks! I don’t like to give up, but being patient is just a important as being determined. I look forward to being active here for a while!

Deleated…Problem solved…It should not have taken this long…