So my supra. When driving over 40 od minutes, starts to sort of stutter/jerk upto 3k revs.
Back ground
Recent build, 6 speed big single. Fully built engine and head.
Twin Walbro fuel pumps, new fuel lines and filter, new injectors
New turbo, mani, oil lines.
New large intake etc.
Literally everything on the car is New including all vacuum pipes, wastegate, bov.
HISTORY
This problem was constant until recently which was caused by a bad alternator which I replace a few weeks back.
Now it seems to only show symptoms after long periods of driving, like 40 mins plus. I still have the standard viscous fan.
And engine bay feels really hot after such drive, auxiliaries to the touch feel hot including the alternator. Feel massive heat wave popping the hood.
Any ideas? Could it be fuel getting too hot or because of the poor cooling of auxiliaries?