Hello HT, just wanted to know if any of you guys know a properly written guide on how to hardwire a 92-95 Civic Fuel pump.

I know it consists of wiring a wire from battery to fuel pump with an inline fuse and relay in the middle some where. But I'm not to 100% comfortable with doing it yet. A guide would ease some worry because I know its a delicate process and if something goes wrong you can risk alot.

Thanks. Any input/tips would be awesome.

 

is it a race car or daily driven?

 

Daily Driver

 

Why do you want to do this? It creates a fire hazard for your car.

 

Because it's the only way my fuel pump can turn on

 

What have you done to try to fix it the right way? Or do you already know what the problem is?

 

This sounds like a bad idea from start to finish. Best to heed Ron@HT's advice and suggestions.

 

I tested for power to the pump and nothing through the wires ; with a known good relay and ecu.

 

When you turn the key from off to ON(II), does the CEL remain on steady or does it turn off after 2 seconds?

Have you voltage tested fuses 31 and 24? Are they blown?

Did you clean and tighten the G101 ground on the thermostat housing?

 

When I turn the key to on the CEL goes on then off after 2 seconds , as you mentioned. I brushed G101 with a metal brush to be 100% sure its not the caused and tightened it back on accordingly. Fuse 24 is 15a for the PGMFI Relay correct ? And which fuse is 31?

 

This^ tells you that fuses 24 and 31, the main relay, and ECU are fine. It should be straightforward to pinpoint the problem and fix it. How exactly did you determine that the fuel pump does not receive voltage?

 

I measured the DCV at the fuel pump plug and nothing.

 

When you turn the key from off to ON(II), the fuel pump connector will receive battery voltage (~12V) for only 2 seconds and then you will measure 0V. Did you just miss the 2 second period?

What did you use as ground in your voltage test?

 

When I turn my key from off to ON (II) I receive no 12v readings despite the main relay clicking as it should and CEL turning off as it should. For my ground I used a unpaint part of the frame .

 

If you are taking the voltage reading as soon as the key is turned from off to ON(II), then most likely the Yel/Grn wire that runs from the main relay to the fuel pump connector is broken. There is one connector (C415/C551) between those two points - check voltage there first.

 

I just checked the voltage going to the yel/grn wire by the main relay when the Key is turn to On (II) and it reads 11.98 for about 2 seconds corresponding with cel. Pretty much 12v's so that's working as it should right?

 

^That's good.

Now do the same voltage test at the Yel/Grn wire pin of C415.

 

Which plug is C551? it's kind of a mess down there. I see a yellow/green wire in this one plug but it doesn't plug up anywhere.

 

Post clear picture from different angles. C415 is a 14 pin connector. It is on the main harness side and connects to C551, which is on the floor harness side.

 

oh ok i ended up finding it. I tested it and it read 14.1 Volts and stayed there even after the CEL went off.

 

That^ doesn't behave like the correct wire and connector. Post pictures.

Trace the Yel/Grn wire from the main relay to the next plug, which is probably somewhere below the main relay.

You are looking for a 14 pin connector, which can accomodate as many as 14 wires.

The fuel pump wire is at pin 4 of C415.

 

Alrighty, I'm going to trace that wire down right now and post pictures. I should be getting a 2 second 12v reading I'm assuming? Also Ron, would it help if you knew that i succesfully got the fuel pump to prime a while back ( Month and 1/2 ago) for a week or sso and stopped out of nowhere. The car sits alot as it is a project.

 

Correct.

I posted a diagram for C415. This should help you recognize it.

It's a broken wire or loose C415/C551 connector. You'll have the problem sorted out shortly by doing a few voltage tests on the correct wire and connector.