New engine codes after spark plug changes (P1391, P0352, P0340)

[Schwifty Rich]

2003 rubicon 5 speed. So I had a misfire code about a month ago P0302 if I recall correctly. I switched the plugs for cylinder 2 and that didn’t fix it. I tested the coil rail with a slow mo camera and all the sparks were visible and in time with its pair. I ended up getting all new spark plugs and boom the misfire went away.

Now I’m seeing these codes and I have an intermittent loss of power and I can feel the cylinders not firing.

On a side note, I’ve recently discovered that my battery may be getting overcharged as a check gauges light came on. The battery needle would kinda fluctuate over 14 a little bit. The code that popped up when I did the 3xon off trick was p1594 but it didn’t show on my scanner.

I have cleaned the terminals and the check gauges stopped for the most part but the voltage on the cluster still fluctuates.

I’m about to really dive into the wiring and check for shorts etc, but everything is wrapped up tight and all have the plastic tubing so it will be a task and a half.
I’m wondering if maybe a loose connector maybe at the coil rail or something could cause these issues.
My plan is:

1 really inspect the wires
2 have the battery and alternator tested and replace as needed
3 recheck for spark at rail

4 replace crankshaft position sensor
5 replace cam shaft position sensor

I wonder that if I didn’t get the plug into the coil rail securely enough though because I’m missing the little red slide piece for that connection.

Any and all direction would be appreciated. I’m going to be unwrapping wires all day today so I appreciate your insights.

 

[Jerry Bransford]

Two questions.... 1) Exactly what brand and model spark plug did you install and 2) did you use antiseize on the plug threads?

2000 and newer 4.0 engines are very fussy about the spark plugs they'll run properly on and some spark plug guides recommend several inappropriate plugs that will cause misfires and a rough idle. And if any of the antiseize accidentally made its way to the electrodes that will cause misfires and a rough idle too since antiseize is conductive.

 

[Schwifty Rich]

I used NGK ZFR5N 3459 and I did not put anti seize on the threads.

Thanks for the response Jerry!

since that was the last thing I messed with I really think that could be it.
about 2 years ago a changed the camshaft assembly ( oil pump drive) but kept the mopar camshaft position sensor. So that’s fairly new.

 

[JKP]

The red piece is a lock. As long as the connector snapped together correctly, missing the red lock won't hurt.

 

[Jerry Bransford]

I used NGK ZFR5N 3459 and I did not put anti seize on the threads.

That plug is fine. I was hoping it was a single-tipped platinum plug like the Autolite AP-985 which could have caused your symptoms.

 

[Schwifty Rich]

I was hoping that was my issue too.

Ive exposed most of the wires between the camshaft sensor and pcm and the crankshaft sensor and the pcm but didn’t find anything. I’m going to test the rail again then take her in for a battery and alternator test. If those are all good, I’ll grab the new parts.

 

[Rubicon88]

How are you testing the coil?

 

[Schwifty Rich]

How are you testing the coil?

I removed the coil rail and the boots and put a grounded metal rod near the exposed springs and cranked the engine. I used a the slow mo setting on my camera to catch the sparks.

 

[Schwifty Rich]

 

[Schwifty Rich]

I can’t get it to go in slow motion but rest assured that I’m slow mo, they are all firing in sync.

also to update I just got back from the auto parts store and the battery is kinda failing he said (cold it had 12.9v) but the alternator was good.

Found this sensor I’m going to buy and see if it fixes the issue next.

https://www.wholesalemopar.com/oem-...yJnk9MjAwMyZ0PXJ1Ymljb24mZT00LTBsLWw2LWdhcw==

 

[Rubicon88]

I can’t get it to go in slow motion but rest assured that I’m slow mo, they are all firing in sync.

also to update I just got back from the auto parts store and the battery is kinda failing he said (cold it had 12.9v) but the alternator was good.

Found this sensor I’m going to buy and see if it fixes the issue next.

https://www.wholesalemopar.com/oem-...yJnk9MjAwMyZ0PXJ1Ymljb24mZT00LTBsLWw2LWdhcw==

The voltage is irrelevant to a point. Its the CCA that's important. How far is it from the rating it's supposed to be?

 

[Schwifty Rich]

The voltage is irrelevant to a point. Its the CCA that's important. How far is it from the rating it's supposed to be?

I am not sure what the actual cold crank amperage was unfortunately.

As I wait for the part to arrive I’ve done a little more research. I’m starting to think I have a leak somewhere, be it vacuum or gasket related.
I don’t have much experience with engine related issues so this article helps me understand the different components that can be effected.
The article I read listed 4 main culprits.

1.) ignition, 2.) fuel density, 3.) compression and 4.) timing failures.

Since I don’t have any fuel mixture codes I don’t think that’s it. I can do a compression test and reevaluate the Ignition system. Timing issues would be something to look into more if the others don’t turn up anything.

I’ve noticed a new build up of oil near the tps/oil filter area. Everything is wet with oil there and the head gasket might be responsible and I already have a replacement so perhaps I’ll have to change that out too. Luckily the cel isn’t flashing so my cats aren’t in danger yet.

I’ll update as I get time to do more

 

[Schwifty Rich]

Installed a new battery, the Optima group 34 agm red top so I feel better about that atleast.

I ran to the store today to rent the tools for a compression test and picked up a noid light kit too while I was at it. When I ran the codes again all that was showing was P0340 which is the camshaft sensor. Luckily I have an old aftermarket one that I never installed when I switched out the oil pump synchronizer. When I removed it I saw this...


Suffice to say it’s not supposed to look like that. It seems the magnet came loose and kept getting worn down by the rotating synchronizer. I’ve replaced it and not had an issue or a code pop up yet but only time will tell. Especially considering this was the crown camshaft position sensor...

I still plan to do the compression test because why the hell not right?

 

[LJBean]

Since your codes started after a spark plug replacement, I'd still be suspicious of the affect of the plugs. I hate to admit, but I've changed plugs without checking the gap and run into similar issues. If you continue to have codes, you might want to pull the plugs and check the gap.

 

[ALScott]

That plug is fine. I was hoping it was a single-tipped platinum plug like the Autolite AP-985 which could have caused your symptoms.

I just got APP985's to put in because I read on here they were OK. Can they cause issues like the AP-985?

 

[Schwifty Rich]

Still plan on doing that compression test so I’ll double check them then.
drove a couple hundred miles and broke 100,000 miles with no CEL so I’ve my fingers crossed still.

Since your codes started after a spark plug replacement, I'd still be suspicious of the affect of the plugs. I hate to admit, but I've changed plugs without checking the gap and run into similar issues. If you continue to have codes, you might want to pull the plugs and check the gap