Re: What would cause 1 spark plug to oil foul?? Viper Engine #3
oh, and you can reduce the gap to .025 from .045 also...
see if that makes it fire through the muck.
The 24 Hours of Lemons Forums → Lemons Tech → What would cause 1 spark plug to oil foul?? Viper Engine #3
oh, and you can reduce the gap to .025 from .045 also...
see if that makes it fire through the muck.
Pulled the head off today. It's obvious something is happening on #10. Cylinder wall looked perfect.
Weird thing. Cyl #8 valve guide is sticking out? Strange.
Swapped another cylinder head, and swapped lifters with another cylinder. Problem is still there.
Looks like its definitely something with the piston/rings.
Swap injectors?
Swap injectors?
+1
And swap coils/ plugs
Swap injectors?
/agree
That cylinder is really clean. Fuel washing the cylinder?
I put some more miles on the car, and it looks like it may be fixed? After we did some quick testing a fresh plug was still dark. After a few more miles it looks better now. I'm thinking now it could have been from cylinder residue from being not running properly for so long? I'm crossing my fingers.
rlchv70 wrote:Swap injectors?
/agree
That cylinder is really clean. Fuel washing the cylinder?
Definitely fuel washed looking. Maybe faulty injector or coil issue, fouled plug after running improperly over time. My guess is the rings and valves/valve seals are fine.
I assumed he cleaned it to inspect.
I assumed he cleaned it to inspect.
Nope, that's what it looked like when I pulled the head off.
Fuel washed because oil fouled plug not burning?
Everyone loves working on someone else's problems... since we don't need to bark our knuckles on the hard stuff!
Talking out my $500 azz, so I can learn from this -
- in the hive mind's experience, would a leakdown or vacuum test on that cylinder relative to a 'normal' cylinder show a difference? I'd say little to no difference if the oil ring is broken, since the oil ring isn't a sealing ring anyway
- once the injector and coil are proved fine, howzabout starting with a new plug on #10 and another cylinder, disconnecting the injectors, then running it for as long as it took to taint the plug, then comparing plugs and scoping the cylinders? No disassembly required -
The clean piston and dirty valves on #10, and the opposite on the other cylinders, is something obvious staring at me I can't figure.
When we put a new plug in, the car runs great and feels like it has full power. After about 10 minutes on track it starts to break up and power loss is really noticeable.
How much difference--from an inspection/diagnosis point of view in general--does checking the plug after a cool down and idle period vs immediately after load and still hot make?
I put some more miles on the car, and it looks like it may be fixed? After we did some quick testing a fresh plug was still dark. After a few more miles it looks better now. I'm thinking now it could have been from cylinder residue from being not running properly for so long? I'm crossing my fingers.
you could have a coil working intermittently.
it could go back "on the fritz" any time
To bring this problem to a resolution.
It was a faulty fuel injector.
During testing at the track we found the fouling plug would follow the fuel injector after moving it around.
Put a new one in, and no more issues.
To bring this problem to a resolution.
It was a faulty fuel injector.
During testing at the track we found the fouling plug would follow the fuel injector after moving it around.
Put a new one in, and no more issues.
good deal.
The 24 Hours of Lemons Forums → Lemons Tech → What would cause 1 spark plug to oil foul?? Viper Engine #3