Misfire issues perhaps more?? (1 Viewer)

[Gonefly470]

No anti-seize (AS).

I'm using 18ft-lbf torque on spark plugs. If threads lubed with AS. I'd actually be, between 27 & 36ft-lbf at 18ft-lbf. A safe torque may then be 10ft-lbf. Which we already have walk out issues at the FSM of 13ft-lbf.

If spark plugs walk out. The combustion gasses well mix with AS in threads and cook. This will stop the walking out as the mix hardens. But will make plugs extremely hard to remove. If not removed soon. Just to break free, they'll be very very hard to turn. Most can't even get them out.

Looks like AS was definitely used when my plugs were installed. I'm am going to remove them all, do the spark and compression. And install new ones without AS. Based on the condition of the #3 plug i removed comapred to the #1 i think this may be my issue.

 

[Gonefly470]

Should I clean out the residue at the base of the spark plug tube? Also do should I remove all spark plugs to do the compression test?

 

[2001LC]

Again I state: I would not use. But, anti-seize on spark plugs threads, does not cause misfire.

I blow out spark plug tubes, with air pistol. Before removing spark plugs.
I'll clean tubes, using a homemade swab: Coat hanger wire, with rag attached by crimp in end of wire. Spray rag with cleaner. T-body spray cleaner or similar.

Compression test:
When I'm just diagnosing a cylinder misfire. I just pull spark plug of the misfiring cylinder, and perhaps one close by, easy to get at, to compare with.

For whole engine diagnostic. Yes, we remove all spark plugs.

In either case:
Engine at operating temp, of 187F or greater. If just test "a" cylinder, I may do with cold engine. This is where, comparing to another cylinder comes.
Fuel must be shut off.
Throttle body wide open.
Battery full charge. To get 250 RPM.

 

[Gonefly470]

Well guys. I want to thank everyone for all the help. Especially @2001LC. Problem solved. I repaced all spark plugs and coils. Everything else checked out. Running like new. Sooooo smooth. CEL is long gone.

All the SPs were barley tight. With a lot of AS on them.

Glad I caught it early. Very relieved.