Random cylinder msifire!!!!!!

[Fast 95]

I already replace the lower intake gaskets less than 500 miles ago. Thats why i put in the new distributor, the hold downs on the stock dizzy split apart, junk plastic crap.

 

[Fast 95]

Alright. I'm having a HUGE problem with a misfire. I know what is causing it, but I donlt know why the plug is fouling out like it is.
On my #3 cylinder, after about 2K miles the whole plug is covered in burnt oil and ashy substance. The gap is usually almost completely closed up and this is causing my truck to misfire like a demon. It even caused the tranny to start messing up b/c of the misfire. Tc would stay unlocked, etc


What in the would would cause the plug to be covered in oil? I've done a compression check and all cylinders are fine

Mine was the same way, only on the #1 cylinder.

 

[RSTahoe99]

Could be a burnt valve though( for both of you)

Fast---did you inspect the heads or replace the head gaskets as well?

 

[JayBo]

any other symptoms of burnt valve?

 

[noremac]

any other symptoms of burnt valve?

rough idle, fouled plug, misfire due to fouled plug, low compression...


An old trick to test for a burned exhaust valve: Cut a 6"x 6" square of thin flat newspaper and place it on the tail pipe with the motor running. If the paper stays away from the tail pipe the exhaust valves are fine. If the paper intermittently sucks back and forth off the end of the tail pipe there's a burned exhaust valve

 

[Fast 95]

Could be a burnt valve though( for both of you)

Fast---did you inspect the heads or replace the head gaskets as well?

No i dident have the heads off.

 

[Fast 95]

Here is a crappy cell phone pic of the #1 plug.

You must be registered for see images attach

 

[noremac]

looks like oil to me.... i am gonna lean towards a valve goin out

 

[Mike]

LS swap time.

 

[noremac]

LS swap time.

i second that..