misfiring while cold not coil error

[MMAFIGHTER121]

So now that winter has finally arrived when I start my car I'll often get a bad rough idle like its misfiring, sometimes if I turn my car off and on again it will remedy itself. If I drive it while it sputters I throw a code and it continues to run like s*!t. However, after it warms up, no more issues and drives like a dream again. I assumed a coil had failed and went to get the code pulled but instead I got:
p0351 Ignition Coil A Primary/Secondary Circuit Malfunction
Now.. I don't know what that meanss 'tall. My best guess is that when I was replacing the VCG those wires that plug into the coils got pinched in as I was tightening them down initially. And caught in there good. I'm wondering if maybe those wires are shorting out in the cold? In any even,t often it'll go days without a hitch and the code willl disappear only to rear its ugly head again a few hours or days later. Whats going on?

 

[MMAFIGHTER121]

bumpenstein.

 

[joegr]

I think that you have four possibilities here.

1. It's a wiring short like you have guessed. I don't think that this is the case because a short would be more likely with the engine hot than with it cold (metal expands when hot).

2. It's a wiring open. This does seems likely because it would be more likely to happen when cold than hot (again, because metal shrinks when cold).
I would pull the coil cover back off and look really hard for any where that the wires to that coil (coil #1) look pinched or compressed. Also check how the connector fits to the coil. If you find a compressed or pinched spot, you will have to cut out that area of the wire and solder in a new length of wire.

3. It's an internal PCM fault, and the PCM would have to be replaced. I have heard of one LS with this problem/resolution.

4. It's a fault in the primary of ignition coil #1. That's not the way that LS coils normally fail.

 

[CrackerJack]

I think your plugs are on the way, when its cold on startup the car runs a richer fuel mix for a few minutes. If you can't get all that fuel out of there it just builds up like a mof and everything wants to go swimming.

 

[joegr]

I think your plugs are on the way, when its cold on startup the car runs a richer fuel mix for a few minutes. If you can't get all that fuel out of there it just builds up like a mof and everything wants to go swimming.

I know of no way that a plug issue could cause a coil primary error code. This is not a misfire code.
He gets a misfire because the PCM shuts down that cylinder (fuel and spark) when it detects the primary circuit fault.

 

[mrshl13]

I had my cold start rough idle remedied by a reflash though it wasn't throwing any codes.