Ok first off I have a 93 civic hatch with an LSV which i did not build, but have done extensive work to since purchasing. I am running a p72 usdm gsr ECU. When i try to start my car I am only getting spark at the very first and last moment the starter begins to crank, none in between. This happens at all four cylinders. My car pop starts perfectly and runs beautiful. That in itself is weird, but it gets better. Since the day I bought the car there has been a jumper wire coming from one of the open 12V "option" terminals in the under-dash fuse panel to terminal 5(with black and yellow wires) on the main relay. If I remove this jumper the relay does not click, the fuel pump does not come on, etc etc. I have changed out the relay for another, as well as the ignition switch, and the situation remains. I have searched forum after forum, googled it, and poured through the manuals, testing the wires to the relay and fuse panel. I have also swapped in a known good ECU. Please help, I have a dyno appointment in 4 days to tune, which is gonna be kinda tough if my car only pop starts. Any insight is much appreciated.

 

The spark problem in ON(III) may be a bad ignition switch. Here's how to test it:




Post pictures of the jumper wire installed in the dash fuse box. This is possibly a crude "kill switch" devised by a previous owner.

 

I thought it was the ignition switch too so I swapped it with a known good switch and still same problem. Pic of jumper coming later. I will run the tests too and post results.