I have a 92 VX hatch, and the fuel pump randomly primes, thus the car won't start. It's been sitting for three years, so I installed a fresh battery, cleaned the T-Stat grounds, pulled the fuel pump, and verified it works with 12V power.

I turn the key to the on position, and the 12 volt side small relay inside the main relay energizes (click) no problem.

The 4 volt side small relay inside the main relay seems to have a mind of it's own. I turn the key to the start position, or just leave it in the on position, and the fuel pump will randomly start, then shut off. There's no pattern of length of time, or when the relay energizes to allow the pump to prime.

I've pulled the main relay out of it's housing, and the PCB solder joints look fine.

Two questions:

Is the 4V side of the main relay controlled by the ECU?

What main relay pins can I jump to just hard wire the pump to run all the time when key is in the on position?

I'm confused because the PCB main relay pin numbers are *** backwards of this diagram.

How to Test the Main Relay in Honda Cars

The car is used for Auto X, and not street driven, so I don't care if the pump runs all the time.


The engine is a swapped JDM H-22 out of a Prelude S with an OBD I ECU. I bought the car with the swap already completed. The car ran fine before it was put into storage.

Thanks in advance for your help.

 

Yes

The ECU is probably bad.

 

RonJ thank you for the diagram. The relay is fine. It appears it as a intermittent connection from the ECU that is a culprit, basically a swap rewiring quality problem. Sorted that, and the car starts and runs fine.

Thank you for your help!

I will post the now running VX on craigslist in Milwaukee tomorrow. The shell's right side is pancaked from my son's adventure with a tree, but the drive train is solid, along with the Koni's, DSS axles, springs, strut bar, urethane bushings, etc.