Troubleshoot *this*, She kicks like a mule Options

[qatar11]

So about 3 hours into our second run after the brake leak (more on that later) we noticed a hesitation or a feeling of a misfire around the 6K mark (7AFE 5spd) as the driving session turned into a 4 and 5 hour run this feeling feel to the 5K mark and into the 4K mark. At the end of the race (call it 15 straight hours of driving) the car was limping around the track in 5th gear chewing up laps - nothing above 3K really without getting the hesitation.... we think its heat related and we think in between driver changes, it gets better briefly - so we think its something that does not retain heat like cast iron.... so.... what do you think it is?

[Hanyo]

it almost sounds like a worn out oxygen sensor or fuel pump. What is your stoichiometric reading during the hesitation. From what i can tell, it sounds like your engine is leaning out during full throttle when the engine begins to heat soak.

7AFE isn't a race engine, you would do better with a S series engine like the 3SGE

It looks like spark plug overheating leading to detonation
try colder thermostat, hood air duct, insulate headers, colder grade spark plugs

The hesitation would not be caused by spark plug detonation because it only happens after heat soak. Once the engine is warmed up the spark plugs will remain the same temperature.

I don't know about fuel cut, but redline is 5800.

red line is different on different year 7afe. It was higher in the older generation before obd2.