Engine is starting to miss when I first start it in the morning. Once it warms up, it goes away. EFI says I am missing on #7. I pulled the plug. Has some green on it, coolant? I think I may have a leaky head gasket. Or could it be something else??

 

well it is not coolant sence GM used the pink stuff.

 

Duh, I knew that. :sillyme:

 

Swap a different injector onto that cylinder, then see if the miss follows the injector. Try the same thing with the coil pack for that cylinder. If neither of those tests issolate the problem, do a compression test on that cylinder and a couple others to see it it's in line.

In any engine you need three basic things: fuel, spark, and compression.

 

Wire on #7?
Pull #8 also, OBD can give you bad data coming from the opposite cylinder.

 

Thanks for the suggestions, I went ahead and installed another plug since I had the old one out. Seems to fix the problem. :dunno:

 

How many miles on plugs? May just need a tune up.

 

Most likely. Was planning on changing them when I do my head swap.

 

Did you find the Missing Engine?

 

Keep an eye on #7. That seems to be the first cylinder to pop on an FI car when you blow a head gasket or piston. I think it must be in the manifold.

 

Thanks, I actually think I have already blown the head gasket.

 

I would do a leak down on that cylinder. You may have hurt the piston. I am not sure about your area, but this time of year plugs get weird colored up in the northern states due to fuel additives.

 

You beat me to that comment!