A random misfire is normally caused by vacuum leaks and bad gas.

Answered by rasmataz
68 questions asked

A random misfire is normally caused by vacuum leaks and bad gas.[/quote]

If there is a vacuum leak wouldn't the idle be a little rough? It's just strange to me that it only flashes when you have the pedal floored. I hooked up my friends genysis scanner this evening and read the misfire counts. #7 was the only one that would spike over 100 counts and I noticed that's when the light flashes. all others stayed at, or very close to zero. I checked the plug and wire. and swapped one at a time with #5 to see if it made a difference. I also did the same with the coils. #7 is stil acting up. Am I even heading in the right direction with this? You guys are awesome!!

Response from ZAKKATTACK
6 questions asked

If there is a vacuum leak wouldn't the idle be a little rough? It's just strange to me that it only flashes when you have the pedal floored. I hooked up my friends genysis scanner this evening and read the misfire counts. #7 was the only one that would spike over 100 counts and I noticed that's when the light flashes. all others stayed at, or very close to zero. I checked the plug and wire. and swapped one at a time with #5 to see if it made a difference. I also did the same with the coils. #7 is stil acting up. Am I even heading in the right direction with this? You guys are awesome!![/quote]

If a misfire in a specific cylinder should lead you to check the spark plug, fuel injector and compression.

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure.

Answered by rasmataz
68 questions asked

Also check the engine coolant temperature and crankshaft sensors

Answered by rasmataz
68 questions asked