Crabbi

thanks again for he response,
i used my bore scope to look in the cranks sensor hole, i did not see anything that looked funny, i will try it again today, i did not go back out there last night, i have to put the timing chain and gears in this morning, but ill respond later on once i try that again.

Thank you again for the help, despite my buddy telling me there are no other errors, hes was kept overnight, I probly wont see him until saturday, if hes ok, im going to try and run through ohming the ignition coil pack plug back to PCM, I never did find a spec for ohms reading on the one wire, one is ground both had 5v orange and yellow, , with no codes its either thinking its doing it right or a sensor somewhere is not registering as a fault, its getting worse each time so eventually something should fail outright and not start or run, im hoping lol

Dave51

See if the cats/exhaust are/is plugged. Check vacuum.

Crabbi

i got busy today and just got back on it this afternoon, i finished up the timing chain replacement, fired it up same thing, actually popped more i think through intake, my buddy wont be around until probly next week, hes having a health issue, i asked him for the graphs, he said next week,
I though about cats myself, when i had the head off i did look down the pipes just to see the inside, it looked clean no carbon tail pipe has allot of pressure, i can run a vac test but not until tomorrow, i forgot i had therapy today and now im sore as heck lol.
I think im back at the cam sensor, The tan or yellow wire has 190 oms that cycle up and down when i ohn it to pin 4 which is supposed to be were a bunch of other sensors ground. i was ohm testing each wire back to PCM previously, any ideas?

Dave51

With key off see if there is voltage at the 190Ω wire (sorry should have made that clear before).

Crabbi

thanks again,

i will try that again tomorrow, i found both the orange and the tan/yellow had 5v, i dont remember if it was with key on or off, more than likely it was key off, but i will try it again tomorrow, I remember thinking why would i have 5v on both wires, at that time i didnt know it was considered a ground until i looked through the wiring diagram,
Ill check it out and let you know

Crabbi

Key off i have 157 millivolts on both the tan/yellow. and the orange wire, power at the tan/yellow on the cam sensor plug. in fact i have power at both the orange and the tan/yellow wires with the key out, the center wire has no volts, i ohmed the center wire back to pin 18 it shows good, when i tried to ohm tan/yellow i get a huge ohm reading that cycles.

Now i think we are on to something, i dont think i should have power at both terminals with the key on the workbench

battery showed 13.75 but thats because i charged it last night, i am wearing out the starter also, i been at this a while now

any ideas?

Dave51

Start unraveling the CPS harness. I think tan/yellow is contaminated by a hot wire somewhere between there and PCM.

Crabbi

thanks for the reply again, i sincerely appreciate this,

I will start checking the harness, i am curios if i can just run a patch harness, the crank sensor and the cam sensor run in sync if i remember right, if thats the case could i bypass the crank and cam sensor in the harness and just add a whole patch harness to both sensors and back to pin 4 and pin 18? if i snip pin 4 and pin 18 at the plug then patch in would i bypass just that part of the harness or would pin 4 wire snipped cut out the rest of the sensors? if its grounded inside the pcm through the circuit board instead of the wires outside the pcm plug that could work and remove the shorted part of the harness?
Im going to start looking at wires,
should both wires have 150 plus millivolts with the key off?

Crabbi

Update, i unraveled the harness up past the injectors breakoff behind the cyl head and went another 6 inchs into the harness towards the pcm so far nothing, i did bare the injector wires also didnt see anything melted, several wires were stuck together but i pulled them apart to look, im sure more are glued together, how far up the harness should i go?, also it breaks off and heads both down and to the passenger side with bulkhead plugs, i did not go into those plugs but i can take them apart to check,
if something is powering it or shorted should i be able to find it through the sensors or fuse box? if its rubbed through and hitting power something else should be affected, I know the rear wiper dont work, has not worked in a long long time, but i unplugged it just in case, the jeep is a sport model so no power windows etc, i did notice the ABS light on, however that was disabled through the fuse panel, pulled the fuse a long time ago just because i didnt like ABS and i left it that way. everything else seems to work like normal, hell i even have the AC working lol..
i did not pull flywheel inspection cover yet to check for broken tone ring or cracked, the crank sensor does sync, i will take a look tomorrow,

Crabbi

second update, i ran a voltage test on the brown wire with yellow tracer or middle wire on the cam sensor plug, with the jeep running i get 120 milivolts, when i unplug the TPS i get 108 milivolts, considering this is supposed to be a PCM ground wire why would i have volts on it?

Dave51

Absolutely! If the 5 waveforms I showed you are normal (there will be 5 in a minute) and fuel pressure, vacuum and compression are normal there's no way in can't start and run.

If you're unable to take advantage of the SnapOn functions, then you're going to have to patiently go through the whole mess. That the K167 circuit is intact, everything has 5V or 12V power that should, and assuming that sensors, PCM and fuel injectors are good having changed them at least once.

Rechecking the flex plate from the bottom is a great idea.

A Direct Voltage Adapter could be helpful in lieu of an o-scope.

Next up in the harness look for spots near heat, turns, exposure, etc. (O2 sensors, fuel pump, battery sensor)

Dave51

Dave51

Those ELM327 bluetooth and software things can give you a rough idea, but their signal acquisition rate is slow so they look screwy. Again, since this seems to be an open/closed loop kinda thing, I'd look closely at that. Above graphs are 2 different situations-- dead sensor and dying cat.

Dave51

Specifically, you have to look to see if this has happened:

Crabbi

t will have to wait for my buddies scanner to get this information, i was looking at a Creader VIII, it shows graphing and is cheap, the videos show timing adv live data so that would at least get me zeroed on the cam sync, which can cause the popping through the intake also,
i went under it looking for spots, everything so far looks ok, the crank sensor plug looked fine, it then runs across the top of the trans and i cant see it, i could see parts of it from the other side but not all, the rest is tough to get to but i can see most of it, i checked all around the exhaust system, exhaust manifold, behind cylinder head, ill keep looking, im starting to wonder, this being a 0331 head that the bridge up top had to be welded and checked for cracks, maybe they missed one, but with a compression test i had run twice and both times was within spec im doubting valves but as it gets worse which it is steadily getting worse, im not sure what it is