2012 Coil, ECM or some other issue?

[Tjharper]

I have a 2012 Edge SEL AWD with the 3.5 with about 132k miles on it.  Last week I got a CEL and a stumble under hard acceleration. 

 

• I had three codes and they were a misfire on cylinder 5 and 6 (can't remember codes) and P0354 ("Ignition Coil D Primary/Secondary Circuit Malfunction").
• Replaced the plugs (I've been meaning to anyway) and cleared the codes.  Seemed to be running better.  I drove about 60 miles with no issues and no codes.
• P0354 came back the next time I started my car (I haven't had any codes from cylinder 5 or 6 since changing plugs). It was also idling and stumbling/missing at about 1500 RPMs.  Seemed to run fine above and below that (except at idle).
• I replaced the coil pack on cylinder 4 (front, passenger side - correct me if I'm wrong). Seemed to be running totally fine.  Let the car sit for about ten minutes and started it again.  It was giving me P0354 again, idling really rough and the headlights and interior lights were dimming/pulsing with the engine (?).
• I cleared the codes to see what would happen and it ran fine, no stumbling/missing, no headlight dimming.  Drove 20 miles with no issues and codes.
• Started it this morning and I could immediately tell it was idling rough.  Drove it into work and it was stumbling/missing at 1500 RPMS (mainly when I was coasting and would put my foot on the gas again).  When I got to work the headlights were dimming like crazy.  I checked the codes and of course P0354 was back.  I cleared it and restarted the car and it was idling perfectly with no headlight issues.

 

I'm pretty lost right now, but the ideas that come to mind are -

 

1. ECM issue.
2. Some sort of battery/alternator issue that's causing the ECM to get less/inconsistent power (?).
3. Some sort of wiring short/issue somewhere.

 

Thanks for any help or advice!

[Tjharper]

I stopped by O'Reilly's yesterday and they tested the battery and it tested as bad.  I replaced the battery (doubtful this was going to fix the issue, but needed to be done and wanted to rule it out).  It ran fine for probably twenty miles, but when I woke up this morning, it was doing the exact same thing (it's about 45 degrees here).  When I got to work, I was pulling into my parking spot and and before I came to a stop and before I put it in park, it started idling and running perfectly.  

[Kozmo]

So I just picked up a nice, clean 2013 SEL AWD with 90K miles and after a month or so, it started doing the same thing.  The code indicated a misfire on #4 and the plugs looked to be original, but not fouled.  I replaced the front 3 (4,5,6) the other night as I didn't have a plenum gasket yet, and I wanted to see if that fixed the problem.  It didn't.  I now have misfire codes on #4 and #6 - and I had replaced both of those plugs already.  Coil packs on the front 3 look fine, no cracking or melting detected - and I'm not adept enough to test them individually myself.

 

So I figured with what I've read so far on the coils, I would replace them as well when I went after the back 3 plugs.  BTW - somewhere else on this Edge forum I found where there is a kit (Tasca Parts #BA5Z-12259-A) that will get you 6 coils, plugs and plenum gasket for $161 bucks!  Keep in mind this kit was meant for earlier Edge models and the plugs and gaskets may be useless, but the coils are the same and you can't beat the price for 6 coils!

 

I had the codes pulled again yesterday for shits and giggles and the computer at AutoZone popped up the same codes (misfire #4 & #6), but led me to a new potential source of my troubles.  Speaking with someone I know with generally good knowledge of such things, he indicated that this part's failure could lead to rough idling, running rough under load or if trying to accelerate from cruising speed (forget about trying to pass someone) - and he said it's failure would throw out misfire or other codes but not typically a code that would point back to this part.

 

So the part indicated is the ENGINE VARIABLE TIMING SOLENOID - there is apparently a left and right part and they are $50+ each.

 

Does anyone else have any experience with this type of issue or with replacing this particular part?  I would like to know these are bad before I replace them - I will definitely get the new plugs and coils installed, which will be a good thing in the end but I am having doubts that it will totally fix my hesitation/loss of power issues.

 

Thanks in advance!