You're mixing your units.
http://hyperphysics.phy-astr.gsu.edu...ic/capeng.html
68000uF at 12V gives 5J of energy stored. Power is time-dependent so 5J in 1 second is 5W which isn't much, 5J in 1/1000th second is 5KW. Say it needs 20 amps=240W then you'd get all of 0.02 seconds at that power, if you could fit it all through those little wires. Might be onto something re. the ECU though.