Originally Posted by W4rdy

I have an xr2i race car. I am having an intermittent misfire but i feel like it’s actually the limiter momentarily cutting in rather than a mis.
I changed plugs leads coil pack etc to rule all this out. My question is... what tells the Ecu the engine revs? Crank position sensor?
what other things could it be?
tps? Edis?
running an after market ecu not ever had problems before this.
any other suggestions?
Thanks