Leftty57

Ok, after all these analysis, I'm not 100% certain that I have a true spark. I had a minor reaction from the engine when I sprayed starting fluid directly into the Air intake but nothing significant. Here's what I'm thinking...I'm not getting any kind of reaction even with fuel in the line, "why" because I guessing the timing chane went out, therefore nether the cam sensor nor the crank sensor give any reading therefore many other circuits aren't being activated. So I get no codes and nothing else to check for, this leads me to the timing chain. I'm guessing timing is the issue but I will be checking the cam sensor before I go to the timing chain. I will post in a couple of days after I make a spark check.

Leftty57

It's now Monday evening, today I went and purchased a cam shaft sensor and installed it. No change! Still no readings, no reaction, everything is still the same. It's looking closer to the timing issue. I will keep you posted.

ET JEEP

The ASD and the Fuel Pump Relays are controlled by the PCM. When you first turn the ignition on these relays should turn on for a few seconds. The PCM controls the relay ground on the control circuit. This is why you hear the fuel pump run for a few seconds at start up. This pressurizes the fuel system. After a short run time the PCM turns the relays off waiting for engine start. When you turn the ignition to start, the engine cranks and the PCM then reads the sensor info for start up.

If the PCM is woking good you should at least have the ASD and Fuel pump relays energize. Attach a test light or horn to the fuel pump power wire and to ground. Then turn the ignition to on and see if you get any action. You can also do it at the relay by runing some thin wire from the relay pin, 87, out above the relay then attach the test light or horn there and to ground.

If you suspect the timing chain, remove a valve cover and look at your valves as you rotate the engine. They should move. I do not believe this engine is an interference fit engine.

Leftty57

I'm not getting energized at the relays when I turn the key. I'm hoping it's not the PMC. I will check the valves or pull the 1st plug.

Leftty57

Ok I pulled the plug, and inserted a long wodden pencil in the hole to the valve and measured the height then I slightly turned the ignition over and reinserted the pencil and it's a lot deeper now into the hole. This tells me the timing chain is on and not the issue. Do you agree?

Leftty57

I'm leaning toward the PMC unit....ok, so, now I did check the power to the ASD and the fuel pump relay with a rigged light tester and do have direct power flow, but no clicking when the relays are inserted nor does the fuel pump engage unless I jump it with a jumper wire, I've changed the crank sensor and the cam sensor, I sprayed starter fluid into the air intake and like the engine wants to start but understandably no go of course but it tells me the valves and pistons are compressing. (Guessing timing chain is good???) I've switched alike relays and still no power fuel pump and fuel guage and alt guage still are down.

Hamster

If it does turn out to be your PCM, open the cover and look at it before you go spending money on a new one.

I had a similar problem with a previous vehicle of mine. I decided that since I was going to have to buy a new computer anyway, I wanted to check out the old one. What I found was a burned out capacitor that got so hot when it burned out, it burned one of the printed circuits in two.
I took just the mother board to my local electronics repair shop to let them look at it. They replaced the capacitor and used one of the excess legs to bridge the broken printed circuit. It only cost me $5.00 parts and labor. I put it all back together and the engine fired right up...........never had another problem out of it.

Leftty57

Lol, good quote. Yes that's the way to go, !just do it!
The thing is I want to do it right the first time without going overboard spending what I would'nt have had to.

ET JEEP

I think what you describe is the piston going up and down. This does not confirm that the timing chain is on and working. You need to see the valves opening and closing. See this link. You see the piston going up and down. The timing chain rotates the cam shaft which opens and closes the valves. Scroll to picture and click on play arrow. The crankshaft rotates and operates the pistons. The timing chain connects the crankshaft to the camshaft. The camshaft operates the valves.

Camshaft

ET JEEP

If you are getting some compression then the timing chain is probably ok. You apparently have a PCM problem. When you turn the key to start both ASD and Fuel Pump relays should turn on for a few seconds. You should hear it click or feel it operate.

As Hamster stated there is a problem with some PCM's where the capacitors breakdown and cause starting issues, no start, intermittent start,etc.

Here is some info on that. PCM Fix

gs69350

Bad pumps will still "pump" however they won't maintain adequate flow or pressure.

I haven't seen any posts where you checked the wiring at the fuel pump connector for incoming 12v. You'll need a multi-meter. If you don't have one, go get one, its cheaper than all the parts you are throwing at it.

Have someone turn the key on while you have leads on the harness to the pump, make sure the pump is actually getting power or not. You should see 12v or thereabouts for a few seconds before pcm turns it off.

You can also use that same multimeter to check your crank and cam sensors. You'll have to google the procedure, but basically while cranking you should be able to measure AC voltage or some kind of pulse.

Get the pinout for the fuel pump relay and insert a paper clip into the ground terminal and check it with the continuity tester in your multimeter against a known good ground (- batt term if nothing else), if continuity, then ground is good. Try not to stick the multimeter probes in the terminals as it will deform the contacts inside so they won't firmly connect with the relay.

Hope this helps.

Leftty57

Thanks ET, I will have to pull a valve cover to check the valve action. Also I would like to note to my Readers that the jeep never stalled on the road nor did it give me any hesitation issues on the road, it was working flawlessly with power and no miss fire at all. I was parked whith vehicle at idle with AC on. I had no previous issues. The vehicle just shut down as if someone pulled the plug off the wall. It never started again.

Leftty57

After pullig a valve cover and inspecting the timig chain I saw they were intact and i had good valve action, my next step was to order a PCM unit. So i did and waited, 10 days for a pre programed unit. IT was worth the wait "Problem SOLVED", it was as I suspected, The PCM Power control module AKA Engine Computer. This was the mystery behind this issue. I connected the harness and she turned. sweet sweet sweet.
Thanks Everyone.

ET JEEP

I know it feels good to have solved that problem. Go show.

nickzdad

Lefty, where did you purchase the PCM?