I replaced ecu and relay. When I jump the relay the fuel pump primes. It still won't prime. I'm at a loss

 

Hello,

Have you checked whether the ground side of the relay circuit, which is supplied by the ECM, is intact and whether power is reaching the power side of the relay from the fuse?

 

The relay clicks, so I assume it's getting power. Will a bad fuel filter cause this as well?

 

I've been chasing a similar problem for a few months now. 94 VTEC, car primed fine for a few hundred miles, then all of a sudden..... nothing. traced the issue to the ECU, bought a new ECU and it worked fine for about 1000 miles, now it's doing the same thing. It'll prime after trying to start a few times, then seems good for a day or 2 and stops working again. Went down the rabbit hole of fuel pump threads on here checked everything that was suggested, watched some youtube videos that explained the difference between Solid CEL that will prime, and a Solid CEL that Won't prime and decided it was probably a bad ic17 chip. I ordered an ic17 chip from Jason Waters Tuning, I should be able to install it next week. Hoping that takes care of the issue.

 

I replaced the ecu and relay. Was wondering if it could be something outside the ecu, relay, and fuel pump that I could look at. I really don't want to run a switch to the fuel pump, but I'm so frustrated I'm about to. I need this thing going quick, I'm about to lose the car i am currently borrowing

 

I thought you were saying that the fuel pump ran when you placed a jumper wire in place of the relay. If that's not the case, what is going on exactly? Do you know whether power is getting from the relay to the fuel pump?

 

Fuel pump did prime when I jumped the 5 and 7 pin

 

Update: went and bought service manual and went through testing procedures. Relay and ecu are good. Moving on to testing fuel pump

 

Fuel pump is good, grounds are good. I'm back at zero. Need help

 

Are you getting a Solid CEL? Even when I hardwired my fuel pump, my car still wouldn't start. It'll prime, but the computer won't activate the main relay and that's the main issue I'm sure is fixed with the ic17. Hope you make some progress, I know it's frustrating AF!