Originally Posted by
abshipp
Definitely a misfire, rough idle but doesn't die. The thing that makes it especially fun is that it only misfires on cold start. If the engine warms up and it's driven a little bit then left to sit everything is happy and no DTC codes thrown.
Thanks, I grabbed a coil just in case but I'll be more than happy to return it. I've got to do this in my driveway tonight so my wife can get to work the rest of the week, so hopefully a new injector fixes it. I'll clean all contacts on the injectors and take a look at the harness assembly since I've got to take the whole damn thing apart anyways. Why does it always have to be the hardest one to get to?
We had a problem with the direct injectors on Chevy trucks starting in 2016. Misfire a little when cold, then fine the rest of the day. No way to test them, just put one in. Yours is the old style, I'm sure. Blow the dirt out of the bore before lifting the fuel rail, put a little WD-40 in there. Lube the o rings with clean engine oil before installing. Hopefully the other o rings are ok.