t3h jam

car is an em1. b18c jdm gsr engine with an obd2b engine harness and a conversion harness for p75 ecu tuned on chrome

so the conversion harness is crappy ebay quality. for a few months now the fuel pump will randomly cut out. has happened about 5 times total. I learned to wiggle the wires and that would fix the problem immediately.

so today I go to start it and the pump doesn't turn on. wiggle some wires, pump primes, and I pull down my driveway. get about halfway down my street and the car cuts out. coast to a parking spot, turn the key and listen for the pump. nothing. wiggle some wires, nothing. tried a bunch of times. fuel pump is not turning on.

so I call my buddy who owns a local tuner store and he happens to have the conversion harness I need in stock. drive down there in my other car, buy it, drive back, plug it all in, turn the key and the pump primes. sweet, I think. all better.

this is where I did something dumb.

with the key still in the on position, I then unplugged the ecu and tried to run the wiring a different way. then I plugged it back in, and immediately heard the relay click and the pump turn on. oh that was stupid I thought, I probably shouldn't have done that.

go to start the car, and it wont start. pump prime, and it cranks just like it always has, but no crank, no glug, not even a hint of wanting to start.

I think maybe the conversion harness isn't the right one? so I plug in the old one and try it. same exact thing, minus the fuel pump turning on (this was the original issue) at least with the old harness before, the car would try to catch and start (with very little to no fuel) but now it just cranks and cranks just like the new conversion harness.

the only thing I can think of is when I plugged in the ecu while the key was in the on position I erased the tune, or blew a fuse for the distributor or something? its so weird. not ever a tiny glug or anything.

I checked the 15a under hood fuse for the ecu and its fine. any other suggestions?

Muckman

iTrader: (2)

The main relay sounds suspect to me.

t3h jam

would the fuel pump prime if the main relay was bad? I have a spare so ill swap it out and see. thanks.

also, did a little bit of trouble shooting today - tried a stock p72 (the car has rc 550's and a 3 bar map but people said it should at least idle) and same thing - pump primes, just cranks, no start, not even a little hiccup or glug or anything. haven't checked spark yet but that's next once I get around to it, i''l post back here with results

holmesnmanny

Just get a new main relay. These things are a dime a dozen at the junkyard.