When I start on some cold mornings get. CEL 0302

Also, interestingly, most of the time this happens I also get the yellow traction triangle in the speedo display.

After running for a while the stumble goes away And if I clear CEL it stays away and runs well until next cold morning. Even when sitting for 8hr in the day, it still runs fine.

First time it happened the morning after a fuel fill up. I have ran 10? Tanks through it since.

Injectors test verified good 1k miles before issue started.

 

Could be the coil or a bad plug wire, have to checked the condition of the plug?

 

New plugs at same time as verified injectors about 1k? ago. and No, I haven't yet pulled out/checked the new plug and will do so. though i would imagine the temp issue wouldn't make a difference on a plug.

 

The only other thing I can think of is maybe coolant is seeping into the cylinder and it miss fires till it burns it off. Loosing any coolant?

 

My gut tells me it's early warning signs of a T-Map sensor going bad.
Bad T-Map will cause rough idle and throw off proper firing.

(But.... My gut had been known to be completely detached from my brain and common sense, be warned)

 

You may be onto something. I am not losing coolant per coolant tank but it seems I'm getting air in the top hose. I'll have to keep an eye out.

Wonder how to test for that. Leak-down test?

 

There are chemical test kits for exhaust gases in your coolant. Avail at autozone etc. 5 min test

 

Yes, have tested several times, so far negative.

I would think that if coolant can get into the cylinder, combustion gases would be getting into coolant. So far thar doesn't seem to be happening.

Maybe a test could be - remove spark plug, pressurize coolant system, see if coolant is in cylinder 2

 

if the test is negative, it’s negative.

any codes?

 

Only the 0302 (cyl 2 misfire) mentioned above and the (oddly) concurent traction triangle.

Yes, combustion gases into coolant test is negative.... Though in theory hardGasses might not be getting into coolant and coolant might be seeping into cylinder - very unlikely. The leak without have to be like a check valve going only one way.

And it doesn't happen every cold morning, only some. Wish it was more consistent. Would be easier to track down.

 

Agree. Not likely.

Did you use inpa to pull codes or other?