Stormtrooper
11-10-2008, 07:53 PM
With Bryan's help last weekend (his tune feels great!) we discovered that my spark plugs were fouled...
My car only has 1600 miles on it, yes 9.X AFR didn't help the matter, but I was wondering why other evoX guys didn't having the same issue. Well, I asked around and the topic of my driving habits came up and I think we have the answer so I guess this thread might be more of an FYI...
I found this at a general EFI/ignition FAQ page:
_________________
When replacing spark plugs, the heat range must be correct for the engine application. Always follow the vehicle or spark plug manufacturers recommendations. If the plugs are too cold, fouling may occur if the vehicle spends a lot of time idling or is used only for short trips (especially during cold weather). If the plugs are too hot, the engine may experience preignition and detonation under load or during hot weather.
In some situations, a slightly hotter or colder plug may be installed than the one normally recommended. Switching to a slightly hotter plug can help reduce fouling in an older engine that uses oil. A hotter plug can also reduce fouling in vehicles that spend a lot of time idling or are used only for short-trip, stop-and-go city driving. But a hotter plug should not be used unless an engine is experiencing a fouling problem because of the increased risk of preignition and detonation.
__________________
Well I live about 4 blocks away from work (I would walk, but i still need my car during the day for meetings, etc.), so my morning and night drive back home are about 1/2 a mile. In other words, my car doesn't even get close to being fully warmed up. My car is most likely not even coming out of cold start open loop conditions, so all these conditions together:
- Short drives to and from work: Plugs don't have time to warm up...The constant rich open loop conditions are coating the plugs with fuel deposits which are normally burned off once the plugs warm up. As a result, the deposits probably just kept building up.
- Stock evoX spark plugs are '8' range.... 1 step colder than the CT9A evos which had '9' range.
- Pig Rich stock tune!
comments, other ideas?
My car only has 1600 miles on it, yes 9.X AFR didn't help the matter, but I was wondering why other evoX guys didn't having the same issue. Well, I asked around and the topic of my driving habits came up and I think we have the answer so I guess this thread might be more of an FYI...
I found this at a general EFI/ignition FAQ page:
_________________
When replacing spark plugs, the heat range must be correct for the engine application. Always follow the vehicle or spark plug manufacturers recommendations. If the plugs are too cold, fouling may occur if the vehicle spends a lot of time idling or is used only for short trips (especially during cold weather). If the plugs are too hot, the engine may experience preignition and detonation under load or during hot weather.
In some situations, a slightly hotter or colder plug may be installed than the one normally recommended. Switching to a slightly hotter plug can help reduce fouling in an older engine that uses oil. A hotter plug can also reduce fouling in vehicles that spend a lot of time idling or are used only for short-trip, stop-and-go city driving. But a hotter plug should not be used unless an engine is experiencing a fouling problem because of the increased risk of preignition and detonation.
__________________
Well I live about 4 blocks away from work (I would walk, but i still need my car during the day for meetings, etc.), so my morning and night drive back home are about 1/2 a mile. In other words, my car doesn't even get close to being fully warmed up. My car is most likely not even coming out of cold start open loop conditions, so all these conditions together:
- Short drives to and from work: Plugs don't have time to warm up...The constant rich open loop conditions are coating the plugs with fuel deposits which are normally burned off once the plugs warm up. As a result, the deposits probably just kept building up.
- Stock evoX spark plugs are '8' range.... 1 step colder than the CT9A evos which had '9' range.
- Pig Rich stock tune!
comments, other ideas?