F-Type
Well-Known Member
- Messages
- 278
- Location
- Gothenburg - Center of the Universe
I broke the code! I think!
Having had these start/stall issues with my octane the last couple of days, with the engine running no more than 0-3 seconds each try.
I think I found the reason why.
It is called fouled spark plug, and is caused by the insulator between the firing tip and the body getting coated with residue that is conductive, causing the voltage to leak this way instead of generating a spark.
Apparently fouling is more common during break-in of an engine. I am not certain why, but could be because the engine should be run more rich during break in, with more gas/oil passing through causing oil buildup on the insulator.
I went out into the garage just before writing this post, took my two plugs and had a look at them, they both looked very shiny on the insulator, pretty much like they had gas on them. I cleaned them in the simplest way with some alcohol and brake cleaner (yeah yeah, it's what I had at hand, its over midnight here right now . Popped one back in the truck, pulled the cord. Guess what! The engine started right away and ran pretty clean for 20 seconds or so . Tried again, same thing, engine started right away on first pull. Much better than before I cleaned the plug. Swapped plug, tried again, same thing, much better result. And this by just a very quick and simple clean of the spark plug. Tried probably 6-7 times, each time the engine started on the first pull and ran about 20-seconds.
For those of you who've seen Hemistorms videos (I've probably not seen them all) he said he had a "gremlin plug", that gave spark when he checked but wouldn't work in the car. Well, for sure he had a fouled one. He also said to get a bunch for break-in. Quite right, they apparently get fouled quickly during break-in. Cleaning could be a temporary solution. Sand blasting is a way of cleaning, I read somewhere. I just might try that tomorrow, as I don't have any new plugs at hand, and the ones I have on order is a week or so away.
Here's a photo of one of my plugs before cleaning, look how shiny/glazy it is, and this plug has been lying in free air for 4-5 hours since I used it earlier tonight, still this shiny. After cleaning the shinyness was gone.
And here's a couple of links to info on fouled plugs:
http://www.ngksparkplugs.com/techinfo/spark_plugs/faq/faqfouled.asp
http://www.aa1car.com/library/spark_plug_fouling.htm
Having had these start/stall issues with my octane the last couple of days, with the engine running no more than 0-3 seconds each try.
I think I found the reason why.
It is called fouled spark plug, and is caused by the insulator between the firing tip and the body getting coated with residue that is conductive, causing the voltage to leak this way instead of generating a spark.
Apparently fouling is more common during break-in of an engine. I am not certain why, but could be because the engine should be run more rich during break in, with more gas/oil passing through causing oil buildup on the insulator.
I went out into the garage just before writing this post, took my two plugs and had a look at them, they both looked very shiny on the insulator, pretty much like they had gas on them. I cleaned them in the simplest way with some alcohol and brake cleaner (yeah yeah, it's what I had at hand, its over midnight here right now . Popped one back in the truck, pulled the cord. Guess what! The engine started right away and ran pretty clean for 20 seconds or so . Tried again, same thing, engine started right away on first pull. Much better than before I cleaned the plug. Swapped plug, tried again, same thing, much better result. And this by just a very quick and simple clean of the spark plug. Tried probably 6-7 times, each time the engine started on the first pull and ran about 20-seconds.
For those of you who've seen Hemistorms videos (I've probably not seen them all) he said he had a "gremlin plug", that gave spark when he checked but wouldn't work in the car. Well, for sure he had a fouled one. He also said to get a bunch for break-in. Quite right, they apparently get fouled quickly during break-in. Cleaning could be a temporary solution. Sand blasting is a way of cleaning, I read somewhere. I just might try that tomorrow, as I don't have any new plugs at hand, and the ones I have on order is a week or so away.
Here's a photo of one of my plugs before cleaning, look how shiny/glazy it is, and this plug has been lying in free air for 4-5 hours since I used it earlier tonight, still this shiny. After cleaning the shinyness was gone.
And here's a couple of links to info on fouled plugs:
http://www.ngksparkplugs.com/techinfo/spark_plugs/faq/faqfouled.asp
http://www.aa1car.com/library/spark_plug_fouling.htm