[charlie66]

Im wondering what others think about the way these plugs are burning.

Number 4 seems rich but what really bothers me is the strap is not showing any timing mark like the other 3..

Using E85 for fuel...

Has anyone here ever had this happen before with there plugs?

[chuckies76ta]

There's a couple of good reads for you. Someone on another form posted info also.
https://www.hotrod.com/articles/spar...eave-hp-table/
https://www.dragstuff.com/techarticl...ark-plugs.html
https://www.onallcylinders.com/2012/...r-spark-plugs/

Ya I can see #4 doesn't even appear to be firing. Try a timing light on #4 wire to see if it's firing.

[johnta1]

Try a new set and see if #4 still looks like that one?
Doesn't seem to be firing correctly.
Check that cylinder for problems?
(plug wire, compression, valves, etc)
Might do a vacuum reading also?

[charlie66]

Originally Posted by chuckies76ta

There's a couple of good reads for you. Someone on another form posted info also.
https://www.hotrod.com/articles/spar...eave-hp-table/
https://www.dragstuff.com/techarticl...ark-plugs.html
https://www.onallcylinders.com/2012/...r-spark-plugs/

Ya I can see #4 doesn't even appear to be firing. Try a timing light on #4 wire to see if it's firing.

Thanks for the links. Ill try the light on 4 . Never thought of that . Thanks

[charlie66]

Originally Posted by johnta1

Try a new set and see if #4 still looks like that one?
Doesn't seem to be firing correctly.
Check that cylinder for problems?
(plug wire, compression, valves, etc)
Might do a vacuum reading also?

Thats 2 runs on a new set of plugs . I even went one heat range hotter . Seemed like theres no color in the plugs..

I did a leak down and compression test . Both were good.

I have a vacuum gage on the column and seems ok .

Im going to swap plugs and see if it moves the problem or 4 stays bad.

Im glad you at least agree that theres someting going on here.

Hopefully its just a bad plug..

[johnta1]

Only 2 runs?

Are these drag race runs or street type driving?
Need to do a full throttle pass then shut off. Idling will make the readings ineffective basically.

#4 looks like it has thousand miles on it.
(jk )

[charlie66]

Originally Posted by johnta1

Only 2 runs?

Are these drag race runs or street type driving?
Need to do a full throttle pass then shut off. Idling will make the readings ineffective basically.

#4 looks like it has thousand miles on it.
(jk )

Street . There brand new probably 4 miles all total. 2 full throttle passes.

I know you're right about shut it right off. But if you look at the other 3 number 4 is just way too far off . Something is going on ..

[Scott65]

If the problem does NOT move with the plug, maybe swap the injector for that cylinder with another.

[charlie66]

Originally Posted by Scott65

If the problem does NOT move with the plug, maybe swap the injector for that cylinder with another.

I was thinking of doing that . But my concern is why the strap is not getting heat in it like the rest. The richness of the plug might be because of that . Once i rule out its not the wire / pug or something other then a related ignition issue ill be looking at the injectors.
Thanks scott..