Try this.

Honda Acura Starting Problems Repair Guide, Main Relay Locations

good luck

 

Look for Online Manuals in the DIY sticky on this site. The 1994 Accord manual has a very nice fuel pump & main relay troubleshooting procedure showing connector locations, connector pinouts, wire colors, expected voltages, etc.

 

Alright, just letting you know, this is what I've done to this point, which is not much: NEW MFR is in place. I pulled the panel in the trunk, found the electrical connections for the fuel pump. Per the advice of the previous posts, I've tested for continuity at the fuel pump when the key is turned from "I" to "II". I get juice at the connector to the fuel pump when the key is turned on. Key to note it STAYS on. The CEL turns off after about two seconds but the power at the BLK/YEL wire at the fuel pump stays on. Thoughts? I haven't checked the OLD MFR in place yet, by the way. Thanks in advance. Key to note: there was a sticky article in which it was proposed to jump a couple of wires at the MFR wire harness; I wasn't able to do this yet -- need to get some smaller gauge wires or something. Is this job critical?? I've seen advice both ways -- to just test it as is, and to jump/splice at the MFR. Thoughts?

I should clarify one thing -- I thought I remembered reading something about, and certainly it has been my experience, that the fuel pump "turns on/runs" for a couple of seconds, almost like a priming - type activity, when the key is turned to "II". I assumed this would be concurrent with a continuity surge at the wire harness in the trunk. However, like I said above, the continuity tester never turned OFF. It stayed steady on as long as the key was in "II" position. No noise from the pump, though.

Sorry for the long windedness, just want to get all the info out there.

Thanks so much in advance.

 

Something's not right. There should be battery voltage at the BLK/YEL wire for two seconds when the ignition switch is turned to ON. Make sure your meter is switched to DC volts, not continuity (Ω), when checking for voltage.

 

Okay, I will give it a shot...btw, never used a meter before...ahhh...what do I set the volts to? It has several different available. . .

TIA.

 

DC volts. Then use the 1st number higher than 12 (usually 20)

 

Alright, here's what I did: Multimeter to 20v (DCV), red to wire harness (BLACK/YELLOW), black to body ground, wife turned key to "II" -- no volts. Quite possible that I didn't have the meter set up -- was hard to simultaneously hold the red probe into the wire harness in the correct place while also holding the black against the body ground. Suggestions? Strip the wires and electric tape? I don't want to take the harness apart. How is it possible that I had the continuity light turn on when I used it, but no volts when I used the meter? Is that even possible? I'm assuming I've messed a step up here somewhere.

 

Use that setting on the battery terminals to see if your meter is working properly (should read around 12.5V).

If you have alligator clips, you can secure the ground side of the meter. Then all you have to do is focus on the red meter lead.

I used a 12V light that I got from radio shack. I can describe in more detail if you do this route.

 

X2 on PAHonda's suggestion: you don't want to be juggling two test leads. Use an alligator clip attached to the black lead and a body ground so you only have to deal with getting the red lead on the connector.

And since the fuel pump isn't running even after replacing the main relay, a quick check of the mechanical integrity for the ECU ground is in order:

Unscrew the 10mm head bolt, clean off any corrosion, and tighten it back up. The ground wire lugs have to be touching bare metal.

BTW, your comment:Jumpering the main relay just gives constant battery voltage to the BLK/YEL wire to the fuel pump, instead of the two-second window when the key is turned on. You've got a helper turning the key on and off so there's no need to jumper the relay.

 

Just to update, here's what I did when I got home: It's possible that last night I had the wrong wire -- there's a yellow and BLUE wire and a yellow and BLACK wire. At any rate, I alligator clipped a jumper wire to the ground and to the black probe on the multimeter. Red probe up inside the wire harness at the BLACK/YELLOW end, for sure this time -- had my glasses and good light. Wife turned the key to "II", and each time I had a reading of about .10 or so. Meter was set on 20v (dc).

I went ahead and tested the NEW MFR too; same deal, when the key was turned, I got a reading of somewhere around .10. To reiterate -- with the OLD MFR, the CEL comes on for two seconds, then off, and there's no blinking D4 light. With the NEW MFR, the CEL is steady on, and I have a blinking D4. Both got the same response from the pump in the "II" key setting -- no noise, no prime, no nothing, and the above mentioned meter readings at 20v(dc).

Coincidentally, I did check the meter on the battery, and it read 12.4 when set at 20v (dc).

Thoughts? Thanks in advance.