the other day i was in a shop doing dyno my car and my engine behave very odd. when my rmp reached 4000 rpm it cuts off and goes back on (its kind jerks).

rx7 93 mod, hks twin power, 1600cc second, 550 prime, supra pump, T40 blowzila turbo, fmic, stock engine.

greatly appreciated for feedback

thanks

 

anyone had this issue before?

 

What is your ECU?

 

power fc