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Mr_C
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hi i had a look at an evo 8 the other night and the engine light flashed when i was driving apperently it was cause the fuel was too low is this true as i have never heard of it on any other car?
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AndyF
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No it's not true. The chances are that it will have been remapped with a feature that flashes the check engine light when engine knock is detected by the ECU. It's not necessarily a bad thing if it only happened once however it depends on what the settings are within the ECU.
Andy
Andy
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Mr_C
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hmm this is what im worrying about its running about 400/400 with an apexi avcr. the light flashed up about 3 times then just slowed down and plodded back. anything else it could be?
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AndyF
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Not really anything else that causes the engine light to flash and it's definitely not a std Mitsubishi ECU feature so I reckon it'll be the knock detection light.
It could be a bad batch of fuel or it could be that the person isn't running it on the fuel it was mapped for e.g. if it was mapped for super unleaded but it's running normal unleaded then that will cause the light to flash.
As I said above, in itself, it's not necessarily a bad thing as such. You'd just need to get the mapping checked out on the ECU to see if it was a major problem.
Andy
It could be a bad batch of fuel or it could be that the person isn't running it on the fuel it was mapped for e.g. if it was mapped for super unleaded but it's running normal unleaded then that will cause the light to flash.
As I said above, in itself, it's not necessarily a bad thing as such. You'd just need to get the mapping checked out on the ECU to see if it was a major problem.
Andy
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Mr_C
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oh right surely if the car is putting up lights and fault codes for knock this isnt good? or could it be down to the low fuel then?
does the knock sensor record crank knock?
thanks
does the knock sensor record crank knock?
thanks
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AndyF
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It will flash the light at a predetermined level of engine knock (or detonation) as it's called. Not sure how much you know about knock etc. but it's basically a measure of if the fuel and air is combusting as it should do. Any abnormal combustion events will cause knock (in very simple terms before anyone tries to get all techie with me 
). Knock can be caused by a number of things but the most obvious are too much ignition advance in the ECU, a bad batch of fuel or running on an inferior fuel to that which it was mapped with i.e. running normal 95RON unleaded in a car that has been mapped for super unleaded.
The light flashing is a safety feature to let you know that a certain amount of engine knock has been detected and that the car is not running at it's optimum performance level. Depending upon what level the light has been set to come on at will depend upon how serious an issue it is. Generally speaking, the levels are set low and are well before any engine damage or anything like that would be caused however if the person who has remapped the ECU doesn't fully understand things or has setup certain parameters or tables incorrectly then the 'knock' could well be causing problems.
Hence my advice to get the ECU settings checked by someone who knows what they're doing.
Andy
). Knock can be caused by a number of things but the most obvious are too much ignition advance in the ECU, a bad batch of fuel or running on an inferior fuel to that which it was mapped with i.e. running normal 95RON unleaded in a car that has been mapped for super unleaded.The light flashing is a safety feature to let you know that a certain amount of engine knock has been detected and that the car is not running at it's optimum performance level. Depending upon what level the light has been set to come on at will depend upon how serious an issue it is. Generally speaking, the levels are set low and are well before any engine damage or anything like that would be caused however if the person who has remapped the ECU doesn't fully understand things or has setup certain parameters or tables incorrectly then the 'knock' could well be causing problems.
Hence my advice to get the ECU settings checked by someone who knows what they're doing.
Andy