Misfire on #4 cylinder

[Slitherbeast]

put some isopropyl in the tank to eliminate water/ice. switch plugs from cyl. 4 to 5. see if the code changes with every trial. if the code is the same cylinder I would try the injector switch from 4 to 5 . if the code doesn't change then i would strip back the injector wiring all the way to the computer plug. There have been some reports of melted/broken wires in the harness. I don't think it is a valvespring...yet. Next step would be coils and takes a bit more work...........have fun!!

 

[QuadFor4]

Sounds like the next thing I do will be to switch back to the OE coil packs that I took off when I switched to the Screamin Demon Coils. The OEs only have about 20,000 miles on them.
Thanks for all of the help with this. If you think of anything else, I am open to try it.

 

[QuadFor4]

What would cause a valve spring to break

 

[ZCx]

time basiclly.

a small flaw in a coil

over rev

lifter prob, as in causin coil bind

probably others

 

[ZCx]

What would cause a valve spring to break

is that what happened???:dontknow::dontknow::dontknow:

 

[VENOMOUS1 RACING]

is that what happened???:dontknow::dontknow::dontknow:

So was I correct? It's seems there are often a small defect during manufacturing that allows breakage prematurely. In tool steel a small pit can cause premature breakage. We have 20 per engine so you can guess at that rate there are flaws every so often unfortunately. You could've had a lifter issue, a valve stick, over revving, (missed gear, wrong gear) etc
Sorry to hear this but you're learning about your beast with hands on experience.

 

[QuadFor4]

Sorry guys but I don't know yet. 70 hours work weeks and crap weather, I havent opened it up yet. I will post up when I find out.

 

[ZCx]

Sorry guys but I don't know yet. 70 hours work weeks and crap weather, I havent opened it up yet. I will post up when I find out.

70 hour work week would be sweeeeeeeet:rock::rock::rock:

 

[QuadFor4]

I replaced the coil today. Looks like a bad coil. No codes and it does feel like it runs smoother.
The plug looks fine. I am guessing the coil wasn't sending enough volts to the #4 cylinder. Maybe I wasn't getting a complete burn?

 

[ZCx]

:rock::rock::rock:

it seemed like it took a few miles for mine to get back where she was.

one thing i did notice. before the coil laid down, oil useage was up.
after the repair & a few miles, have not had to add any. weird

 

[QuadFor4]

I started using little oil recently also. I just chalked it up to 'normal' usage that I've seen others post about. It never got bad, only about 1/2- 1 quart between oil changes. I will keep an eye on that as well.
Thanks to all for the imput and help with this.