Brad2Taylor

Hello everyone! I'm new here, but from what I've seen, this is a great and helpful forum. I hope someone here can help me.

Short story is I have a '97 Acura TL 2.5 and my fuel pump will not run, but is functioning if connected directly to the battery. I've done some pretty extensive troubleshooting already and I dread that the problem is in my ECU.

Recently, my car stalled on the road shortly after leaving a parking lot. I ended up having it towed back to my house. It had given me trouble starting (long crank) in the parking lot and also a few days earlier. Since getting it home, early in trouble shooting, I actually got it started a couple times (seemingly random) for maybe 30 seconds before it would shut off again.

I've gone though some troubleshooting on the main relay, and I will link them below. Here is the most relevant part.

Main Relay Terminals: For most Accords: While still connected to the vehicle check that:

1. Yel/blue should have +12 volts battery, always.
2. Blk should be grounded always. Connect your negative voltmeter or DMM lead here.
3. Blk/yel should have +12 volts with ignition ON.
4. Not used.
5. Yel/blk should be +12 volts with ignition ON.
6. Blu/Red (auto only) Blk/grn (manual only) should be +12 volts at START.
7. Yellow should have +12 volts temporary with ignition ON, if idling or start Yellow should have +12 volts.
8. Grn/blk should ground temporary with ignition ON or idling, if idling or start Grn/blk should ground.

If all readings are okay except on either terminal 3) ECU-Injector or terminal 7) Pump then the relay is dead and should be should be soldered.

First of all, I am not 100% sure that this is completely relevant to my Acura, but it is the best I could find.

Everything checks out until I get to terminal 7. My thought is that terminal 8 is the problem. The diagram shows that it is ground to the ECU, controlling the relay. It would close the relay and supply voltage to terminal 7, thus running the fuel pump.

I checked for continuity between terminal 2 and terminal 8. Is this the proper way to test this ground? If so, there was no continuity. Where can I go from here?

Relay and harness test
Main Relay Fix, Troubleshooting (Honda, Acura) and how to solder
How to Test the Main Relay in Honda Cars

Relay Diagram
http://breebamboo.ipage.com/archive/...laydiagram.gif

thoiboi

Have you tried buying a new main relay

Brad2Taylor

Thank you for your reply!

I have not, as I would like to be more confident before spending the money.

thoiboi

If you're handy with a soldering iron, you can reflow the solder as the joints can crack over time. Else sounds like a new main relay might be the next step

Brad2Taylor

I may have to suck it up and make the purchase, unless someone out there has some troubleshooting tips that I'm not aware of. Thanks again.