my fuel pump won't prime in my 91 ef dx. it was running great until i did the first hard pull in it since the motor swap, and right before 2nd to 3rd it died. since then i have replaced the main fuel relay, swapped to a working ECU dropped the tank and confirmed the walbro works when hooked to a battery. does anyone know what it could be?

 

What swap?

Back to basics:

Have you checked whether the hood ECU fuse or the dash fuel pump fuse is blown? Does the main relay get voltage from both fuses?

Is the G101 ground on the thermostat housing clean and tight?

CEL codes?

 

i swapped in a jdm b18c its a brand new engine harness, the dash and under dash wiring harness is a clean completely uncut stock harness, the rear harness that runs from the fuse block to the fuel pump and tailights is brand new from honda. the ecu fuses under the hood are not blown. its a brandnew thermostat housing and is not corroded at all. The motor turns overs fine. I have a solid CEL with the key in ON. I'm converted to MPFI and OBD1

 

Try to directly answer each question I asked - point by point.

 

jdm b18c

no fuses blown

the main relay has power to each pin

the thermostat ground is good

i tried to connect my orange and blue wire on my ecu jumper harness from phearable, the CEL stays solid

 

http://www.phearable.net/tech/wiring...schematics.gif


Unplug the OBD1 ECU connectors A and B. Turn the key to ON(II).

If you ground terminal A7 or A8 in the ECU connector A, does the fuel pump run?

Do terminals A25 and B1 in the ECU connector A or B have battery voltage?

Do terminals A26 or B2 have continuity to body ground?

 

i will check those and get back to you, thank you for the help. Also i just found out i have no spark.