P1391 VIDEOS Huge list of diagnostic work need suggestions please!

[allevolution]

2000 Cherokee 175k Been fighting this for almost a year.
Let me give a short summary of my issue.
-It is an intermittent spark issue
-Fuel pressure is where it should be
-Compression is 150-155 cold

EDC codes that are reoccurring
P1391- intermittent loss of cam/crank
P0340- cam circuit malfunction
(havent seen this one in a while and I think I resolved this)

P0351- ignition coil a malfunction
P0352- ignition coil b malfunction
P0353- ignition coil c malfunction
P0132- sensor 1 high voltage
(rear O2 is out, this may be to issue with heater circuit)


-90% of the time Hard starts, will have to cycle the key 2-5 times. Sometimes it will start first turn of the key. Doesnt matter is the motor is hot, or cold.

-Once is it started, 50/50 chance it will run like pure shit (misfiring) and have to be turned off then restarted again.
(still has hard start if turned off either way)

-If it does start without an issue, idle will be normal but it will still have a problem when I apply load to the motor. Accelerating up to highway speed (40-50mph) it will struggle.
UNLESS I floor the pedal WOT, the motor will accelerate quickly and the misfire issue will rarely show up again.
(further into this I will have to floor the car several times then the misfire will disappear)

-VERY rarely will it have an issue with misfiring after running for sometime.
(Issue happens mostly only at startups)
If this rare situation does occur, it will misfire at complete random.

I think I have the major bullet points there.
With all that being said if we have a warm day (Chicagoland weather)
Seems like initial start up is alot easier.
Would an IAT have any affect on anything?

But onward with the long list of parts:
-Cam synchronizer/ oil pump drive DEALER part
(and calibrated 110% accurately using snap-on scanner)

-Cam sensor NAPA part (swapped with dealer part with no difference)

-Crank sensor DEALER part (swapped yesterday with another new dealer part and no difference)

-PCM from autocomputerexchange (out of Flordia reputable place)

-PCM Black connector (connector was a little jiggly and had seen better days, now its tight and every pin is making full contact)

-All wiring from Cam sensor to PCM reads fine with meter.
Same with Crank sensor wiring.
All connectors are tight, no wiggle room and pins in both connectors are tight.

-Fuel injectors where cleaned with new o rings
-New TPS

I am really at a loss here please someone, anyone help me out with an idea!

Videos that show everything that is wrong.
Please please please watch all of these videos it will really give you a perspective of whats going on with the car and when it attempts to start, or is running and starts to have random misses.

http://www.youtube.com/watch?v=wmjgTYyvOdE&feature=share&list=UU4rY4AwCg4hOtIEkpWxy44w

http://youtu.be/cOB7oY_hfQc

 

[winterbeater]

Good post. Anyone in Chicago got a coil rail he can try swapping?

 

[allevolution]

Thanks I try haha.
I was going to buy one from napa,

But then I realized theres no way that would fix the P1391 intermittent code would it?

Add to those parts
-Coolant temp sensor (sometimes people say this can cause a rough start, or rough running at startup)
-Missing the NSS (rigged to run only) so I am about to install a new NAPA one right now.

 

[allevolution]

Im starting to guess that whatever advances the spark is causing all these issues.
Because majority of the time its only when the rpm is increased under load.

How is the spark advanced? Or what controls spark advancing?
And would WOT have a default setting that would explain all of this?

 

[Tim_MN]

Always fix any known issues, ie the O2 sensor. A weak O2 sensor can send confusing signals or incorrect data. When finally heated to the correct temperatures by exhaust gases it may send good enough data for the engine to run smoothly.

What have you done to address the coil rail codes ?

Always trouble shoot the lowest numbered trouble codes first. Higher number codes can be caused by bad data from the faulty parts causing the lower numbered codes.

WOT causes the PCM to ignore all data input from most or all sensors.

The PCM controls everything, but given bad data it may not do the right thing.

 

[Tim_MN]

What brand/type/number spark plug's are you using ?


I watched the video again, why have an external regulator on the battery ???

Also, the starting symptoms are similar to what happens when the PCM re-boots due to voltage issues. The changes in the running characteristics after a successful start point toward cam sync issues.

Are you sure the Cam Sync is correct, and have you seen this ? -> Scan tools, O Scopes and toothpicks


For 1996+ Jeeps, the OBD-II engine computer (ECU/PCM) re-boots, and the idle settings are deleted, when you: (1) let the battery run down by leaving the lights or radio on, (2) disconnect the battery for an extended period of time, (3) when the battery goes bad and needs replacing, (4) when the alternator is not properly charging the battery, (5) or when poor battery connections result in a voltage drop at the PCM or poor battery charging.

Loose, corroded, or damaged battery cables or ground wires may also cause or contribute to the problem.

Your symptoms are: (1) having difficulties starting the engine without depressing the gas pedal, and (2) the engine will have a low idle and probably stall unless you keep your foot on the gas pedal. (3) The ECU will relearn the idle settings after a short period of driving and the engine will start and idle normally.

Begin with basic trouble shooting of the start and charge systems. Remove, clean, and firmly reconnect all the wires and cables to the battery, starter, and alternator. Look for corroded or damaged cables or connectors and replace as needed. Copper wires should be copper color, not black or green. Do the same for the grounding wires from the starter to engine block, the ground wires at the coil, and the ground wires from the battery and engine to the Jeep's frame/body. You must remove, scrape, and clean until shiny, the cable/wire ends, and whatever they bolt to. Jeeps do not tolerate low voltage, bad connections, or poor grounds.

If the symptoms reoccur, you need to have your battery and/or the alternator load tested at a repair shop or auto parts store. This is usually a free service they offer to bring in potential customers. Even with low battery voltage, the engine will start, but the ECU can re-boot multiple times and a new battery may be required.

 

[gradon]

Im gonna x2 the cam sync and check the coil pack, dipstick, and firewall grounds.

 

[allevolution]

What brand/type/number spark plug's are you using ?

Pretty sure I went with NGKs, nothing to expensive like iridium but I didnt go the cheapest either.

why have an external regulator on the battery ???

High output alternator I had for some audio I use to be into.

starting symptoms are similar to what happens when the PCM re-boots due to voltage issues.

Can you explain this a little further?
Seeing too much voltage? Too little?
I use to run the car on a 14V system (16.5V charging).
But after having issues with that (which is why I replaced the PCM)
I ended up back with a 12V system. External regulator doesnt use any of the OEM field alternator wiring, but I dont think that would affect anything.
Edit: I have just read the below explanation.

The changes in the running characteristics after a successful start point toward cam sync issues.

This is the same thing I thought, But I have checked the cam sync countless times at this point. So not sure where to go with this one.

Are you sure the Cam Sync is correct, and have you seen this ? -> Scan tools, O Scopes and toothpicks

That article is pure gold! Sad thing is I can relate to the article, where he mentions the entire camshaft synchro spins in the block itself. Its really a bandaid design in terms of changing to coil ignition (thanks Chrysler for that)

But after reading that Im not so sure.
I had originally adjusted the synchro using the toothpick method with #1 at TDC.
And then when I brought the Jeep around to my friends shop he monitored it with his snap-on scan tool and told me I was almost perfect. Within 1-3 degrees of rotation perfect according to the snapon tool. And then I adjusted it according to the tool.
I would assume the snapon tool would make the perfect adjustment because it takes into consideration all the other sensors timing ect.

But that has me wondering about timing chain stretch. Because with 175k on the original timing chain I always considered how that should be adjusted.
Guess I will try to compensate for that stretch. But How much is the question now?


The thing that has me confused the most is I never had an issue with voltage or current drop. But I recently found out the 0 gauge I have been using from alternator to battery is not rated for the output of the alternator. And even seen a surge problem show up recently at random. But then I never seen it again and probably should of thought more of it, but I didnt.
(what affect could this have on the sensor system? Does sensor translate info by grounding the signal given to it?)
I found this out when I seen a fried grounding wire from the alternator to the battery.

I am awaiting the charge cables for the battery. Decided two runs of 0 gauge would be a good idea for the charge side, also two for the alternator to battery ground. Also ordered new cables for the motor grounding points.

Will check back in after this is all together see where it leads me.

 

[Talyn]

Im gonna x2 the cam sync and check the coil pack, dipstick, and firewall grounds.

x2

Check the wiring harness behind the head. It is known to rub through there.

I got the P0351, P0352, P0353 codes when I had a bad crank sensor. Since your sensor is new I would check the wiring.

However I would start with reindexing the cam sensor drive and check the sensor itself as well. Sometimes the magnet falls out. This articles gives some information similar to your problem as well as how to reindex the sensor. http://jeep.blackonyx.net/pdfs/jcss.pdf

Edit: I didn't read the last part of your last post prior to posting. Being that you verified the sync with the Snapon tool I think we can rule out timing chain stretch. The timing chain is the mores link style which technically should remove slack while running. I'd check the wiring next. I doubt its the coil pack as all coils usually don't fail at the same time.

 

[Sidewinder CC]

Those P035X codes may be attributed to a low voltage from the ASD relay to the Coil Rail.

Try this:

Either using a 12 volt test light or a voltmeter, unplug the Ignition Coil Capacitor connector.

Start the engine, using a 12 volt tester, connect it to engine ground and probe the capacitor connector. You should see the tester light illuminate brightly. If not, repeat using a voltmeter. You should see battery/alternator voltage. If not, go to the Coil Rail connector and back probe the connector at the Dark Green/Orange tracer wire then repeat the voltage tests.

If the voltage is considerably lower than B+ voltage, shut the engine down and pull the ASD relay. Inspect the relay pins for corrosion and the relay pin sockets for corrosion. If they look okay, swap the ASD relay with the Radiator Fan Relay. Repeat above test(s) to see if the voltage has been restored to B+ voltage. If not, there's high resistance between the ASD relay and fuse 18 in the PDC, or between fuse 18 and connector C107 (next to the tranny dipstick), or between C107 and the Coil Rail.

 

[Mar]

I just went through similar problems on my 2000. From memory, this appears to have the same codes and intermittent stalls or starting problems.

Long story short, after replacing few sensors and after some time spent on wiring, it turned out to be simply a dying/weak battery.

X2 on verifying grounds and wires, especially the wiring harness behind the head. It wasn’t my case but it’s a matter of time before it will rub through.

 

[allevolution]

Check the wiring harness behind the head. It is known to rub through there.

I have checked the wiring numerous times. Even had the entire harness apart up to those sensors. Not only me, but my Chrysler master tech friend could find No breaks in the wiring, and there is no resistance in any of the wiring from the cam, or crank sensor from sensor to PCM.

...it turned out to be simply a dying/weak battery.

Almost new D3400 battery, which is high amperage capable and high reserve.

Those P035X codes may be attributed to a low voltage from the ASD relay to the Coil Rail.

Try this:

Either using a 12 volt test light or a voltmeter, unplug the Ignition Coil Capacitor connector.

Start the engine, using a 12 volt tester, connect it to engine ground and probe the capacitor connector. You should see the tester light illuminate brightly. If not, repeat using a voltmeter. You should see battery/alternator voltage. If not, go to the Coil Rail connector and back probe the connector at the Dark Green/Orange tracer wire then repeat the voltage tests.

If the voltage is considerably lower than B+ voltage, shut the engine down and pull the ASD relay. Inspect the relay pins for corrosion and the relay pin sockets for corrosion. If they look okay, swap the ASD relay with the Radiator Fan Relay. Repeat above test(s) to see if the voltage has been restored to B+ voltage. If not, there's high resistance between the ASD relay and fuse 18 in the PDC, or between fuse 18 and connector C107 (next to the tranny dipstick), or between C107 and the Coil Rail.

Funny you mention this, I unplugged my asd capacitor completely
(is that a bad idea?)
And Im not 100% sure it was all because of this, But they car started easily today 3/4 times. And only started to miss after the last successful start.

But I will go check all of the above and report back with findings. Thanks alot for the detailed explanation

 

[Tim_MN]

Since you have coil rail codes, I would consider a new or used coil rail as a diagnostic test.

I remain suspicious of your alternator output, and wonder about the wiring.

Have you pulled the cam sensor assembly and checked its condition ? I pulled one at the junkyard a few weeks ago, the end of the shaft was all chewed up and nasty and the splined portion was extremely worn. I think I have read that that 2000+ TJ Wrangler 4.0's have all kinds of issues with cam sensor assembly wear and breakage.

I would suppose that the snap-on tool is correctly setting the cam sync, but given the problems I would want that confirmed by another different DRB-III tool.

 

[Talyn]

Have you pulled the cam sensor assembly and checked its condition ? I pulled one at the junkyard a few weeks ago, the end of the shaft was all chewed up and nasty and the splined portion was extremely worn. I think I have read that that 2000+ TJ Wrangler 4.0's have all kinds of issues with cam sensor assembly wear and breakage.

I failed to mention this, but good point. The cam sensor drive can bind up leading to worn or broke teeth, mostly isolated to TJs, but can happen on the XJ.

 

[allevolution]

Since you have coil rail codes, I would consider a new or used coil rail as a diagnostic test.

I remain suspicious of your alternator output, and wonder about the wiring.

Have you pulled the cam sensor assembly and checked its condition ?

And I had a bad (brand new) crap napa oil pump that i drove on for a while.
(one of the two tongs on the drive shaft for the pump broke off)

And this made my cam synch move all about erratically.
(such as move all about and eventually broke off the retaining bolt in the block, had to drill and tap size bigger)
I am not thinking to myself I should buy another one just to test it out. Since this could be an issue thats more than what it looks like.

The teeth are a little chhewed up on it, but I didnt think twice about it since I know it was the oil pump causing this issue.

Alternator output is good. I even have an after market voltage gauge in the car. Stays at 14V all the time. Even while cylinders are missing

 

[allevolution]

Try this:
Start the engine, using a 12 volt tester, connect it to engine ground and probe the capacitor connector.

I did not see battery voltage at either of these at key on.

If the voltage is considerably lower than B+ voltage, shut the engine down and pull the ASD relay. Inspect the relay pins for corrosion and the relay pin sockets for corrosion.

No corrosion, I tried swapping the relays and nothing different.
Hard start, and eventually a miss.

If not, there's high resistance between the ASD relay and fuse 18 in the PDC, or between fuse 18 and connector C107 (next to the tranny dipstick), or between C107 and the Coil Rail.

Would this indicate a break in the wiring?
I remember taking apart the fuse box a while ago and checking this wire for a short or break.
And I found nothing but I would be more than happy to check again.

what is the PCD?
also is the the black connector near the coil pack and NSS connectors?

 

[Sidewinder CC]

I did not see battery voltage at either of these at key on.

The engine has to be running to see voltage at the capacitor and/or the coil rail connector. It would be impossible to start the engine (no ignition) if you had no volatage. Try again to see if the voltage is low, using a digital voltmeter.

No corrosion, I tried swapping the relays and nothing different.
Hard start, and eventually a miss.


Would this indicate a break in the wiring?
I remember taking apart the fuse box a while ago and checking this wire for a short or break.
And I found nothing but I would be more than happy to check again.

what is the PCD?

Power Distribution Center (PDC)...the 'fuse box'.

also is the the black connector near the coil pack and NSS connectors?

Yes, the C107 connector is one of three connectors at the tranny dipstick. Two Black, one Gray. See pic.

Before going any further, determine if there is a significant voltage drop between the ASD relay and the Ignition Coil Rail.

With the engine running, determine and record the system B+ voltage using a digital voltmeter by probing the battery positive post connector with the meter positive probe and the battery negative post connector with the meter negative probe.

Repeat the voltage checks again with the engine running, at the capacitor connector, and if neccessary, at the back probe inserted in the Coil Rail connector (as described in previous post). The voltage available should be very close to the voltage determined above. If it is significantly lower than B+ voltage, further troubleshooting will be required.

 

[allevolution]

Thank yo so much for your help but I have to give up.
Jeep is forsale, dont have the time to put into figuring this misfire out anymore.
Its my only car and I cant risk loosing my job (This would be job #2) because of it.

Check it out the NEW parts list is through the roof. All receipts included.
Someone will get a good deal on a bunch of new quality parts alone.

http://www.cherokeeforum.com/f70/ch...parts-list-receipts-prove-184269/#post2699631

 

[kastein]

I know the answer but threatening to come kick my ass and use the insanity plea as a defense is not a good way to get me to tell you.

I'm glad to hear that you have been fighting this problem for the last year (ever since you threatened to kick my ass) because that cracks me up, you claimed you knew what was wrong last time we spoke.

How is that going for you?

Cheerio! I will leave the light on for you, x91evo :wave:

PS: This is all because you were a complete a-hole to someone on here with your other account and I saw it. If you want help, being an a-hole to other people on here is not the way to persuade us to give it to you.

This is the last time I am replying to this thread; raging and/or threatening to kick my ass (again) will not change that.