I had done a compression test as well as the dealer and all cylinders were reading good on the compression test but have not done a leakdown test. From what I see on the plugs #6 cylinder fires on occasion but plug end as well as the threads are wet with fuel. But will deff have to look into the leakdown test and obtain a tester or make one for it... Just cruising around you can feel it start to miss on occasion and the engine just starts to bucks hard.

What should I look for specifically other than carbon buildup or wet plugs?


vizi

 

Weird! I'm having the exact same issue on the same cylinders! Have spark and fuel, have swapped to known good injectors. I'll be following this thread. Compression is meh on 8 but fine on 6, same as the others.

 

I have even gone as far as to take the head off the pass side to check the pistons and valves all seem good.I have been working on this for a few years now... Some how I gonna beat this...

I can also tell when something is a miss as the water temp gauge is just barely above the cold line and when it seems to run a bit better the water temp gauge will rise closer to the middle of the gauge. I have also put in a new cooling temp sender on block a while ago and mage double sure I put in the thermastat in correctly.


vizi

 

I have an 01 Durango w/a 360 ("5.9") that is driving me nuts as well, also on #6.... its currently sitting dormant in garage, because I am so POd at it I have 2 more side jobs to do and then to dig back into that one....

 

Have you checked your timing since doing your new timing chain? Are you sure the sprockets were linelined up correctly? How about checking your distributor timing? Have you checked for stuck valves or bad valve seats? Also I'd tear further into your harness and go even deeper. See if there's a wire that's grounding out that you couldn't see, you could check with a multimeter as well. Also try swapping a new distributor pickup and a new crank sensor. I e seen cam sensors on other engines that would misread the cam position but only on one spot

 

Yes sir I double checked the timing when I installed it as I turned the crank 2 times over to make sure all was right. As for the distributor I thought it was controlled by the PCU/ECU as I have put a light on it at cold idle as well as warm idle and the marks would never appear even after I put marks on the crank and still nothing.I checked the valves and saw no light on either the exhaust or intake side when I had the head off.valve seat I am not sure about I added some zddp to the oil to see if that helps but nope it sure didn't. My next step with the wiring harness is to trace it back to the PCU/ECU with the buzzer on the multimeter but was hoping to only have to do that as a last resort as I HATE electrical issues. I have not touched the distributor pickup or the CPS as of yet. Currently it's 20* out so not having anything to do with that today.


vizi

 

I feel your pain.....If I can ever figure this out I sure will post the fix/cure.....


vizi

 

How about checking for sticky lifters. I've noticed a few of the 5.2s that I've worked on have had their lifters stick or get really tight in their bores

 

One last thing. Have you read the TSB about the plug wiring on these motors?

You may have crossed wires causing a misfire on only one cylinder.

RwP

 

I only pushed on them slightly maybe 1/16" at most mainly to make sure it was seated to see if light could be shinned through. But did not check to really make sure they traveled full length to see if I could feel a rough spot or sticking feeling.

I can try an additive but that seems more like a bandaid fix to a mechanical issue.

vizi