I ran the test in the helms on page 11-125

Basically you jump two wires (5 and 7) at the main relay and check for voltage at the 2 pin connector for the fuel pump while the ignition is on.

The 2p connector did have voltage so the helms says to replace the pump.

Excuse my ignorance, but why does this mean the pump is bad? If i plug the connector into the pump with 5 and 7 still jumped at the relay, the pump will run like no tomorrow..

I tried 2 different relays that both click on, grounds are fine, ecu is good, fuses aren't blown, pump just won't prime when the key is switch to on. Car cranks fine and has spark.

Sorry if I'm confusing, I just want confirmation that the pump is for sure what needs replacing even though the helms says so, lol.

 

""""The 2p connector did have voltage so the helms says to replace the pump. """"

I think you read this wrong...just sounds wrong. In theory, if you have to jump OVER the relay in order to get voltage to the pump (and then, even better, the pump works), then it would be a relay issue.

I am not there to trouble shoot with you or I would, but put the relay in, unplug the 2plug harness at the pump, and then measure the voltage while a friend turns the key on and/or cranks). If there isn't voltage when the relay is being used, then it is indeed a relay issue.

Since you say you have tried a couple relays already, I would go back and re-read and re-check the wiring info to the relay.

 

Your theory does sound a lot more logical I'll admit.
I looked for voltage at the 2p with the main relay in and the key switched on and got nothing out of both relays. The relays are powering up the ecm, though, so it's possible that the second relay within the main relay just isn't powering the pump, but it's odd that both relays are having the same result. The helms manual often states to check for continuity while troubleshooting which I can't do on my cheap multimeter, so I guess I'll go out and buy a more complete unit.




the test procedure I used is on page 366 of this pdf
http://www.scribd.com/doc/4693/Prelu...l-9296-4th-gen

 

Your average multimeter can measure resistances and voltages. Yep, check out those relays. Simulate the whole setup with 12v and ground and measure the output on the output prong?

 

Both relays just checked out fine in the continuity test.
I guess I get to check for wire shorts now?

 

It was the ecu. My Jdm ecu started it right up, but I'm curious as to what could cause my usdm ecu to go bad? It's not completely dead as it will still power up and throw codes, but the fuel side of it must be malfunctioning? Can this be repaired somehow? I'm also concerned if something in the car might fry the jdm ecu over time as well.

I forgot to mention that I installed the usdm p13 along with a vafc1 about a week ago, the ecu and p13 were used together for several years before I ever got them, so this leads me to believe the vafc had nothing to do with it.

Since posting I've also opened up the usdm and can't find any physical damage or evidence of anything particularly wrong. I have a p14 ecu for spare parts, but it sucks not knowing what needs replacing.

 

If the relay is good, then it is NOT getting the signal to power on the pump....simple as that, buddy.

find your schematic, and measure the voltages/ground signals on every wire involved in the fuel process.



I would actually check the pins on my ecu (with the harness off) and make sure none are bent. This happens from time to time. One bent pin = major PITA troubleshooting.

Have you tried the USDM p13 WITHOUT the vafc? I am not familiar, but check all connections/pins with all vafc wiring.

 

Makes perfect enough sense and you're right.


Is it still worth the effort to do this if I for sure know the ecu is the culprit?


None are bent as far as my eyes can tell.


I did unplug the vafc and attempt to start the car with the usdm ecu at one point, but the car starts and runs fine with the jdm (and was running perfectly fine with the usdm ecu until it crapped out), so I'm not sure this would help, but I can try anyway.


I'm fairly sure it's the ecu that's not powering up the second side of the relay. It's not uncommon for the caps and other parts of the board to go bad on Honda ecus of this age, it confuses me that none of the parts are visibly blown, but the fact remains that the pump won't prime anymore with my usdm ecu and it will with my jdm.

I appreciate your help by the way.

 

Have you narrowed it down to a specific wire (that comes out of the ECU)? if so, check that exact pin on the ECU.

Further suspicions in my mind make me ask, does it still run with the "good" ecu AND the vafc installed? (I have no idea how to wire up a vafc, but I wonder if it is spiced into that fuel wire I just asked about.)

Also, this is good to know....if the other ecu operates EVERYTHING fine, then: the relays are good AND the wiring is good.

So, yeah, that narrows it down to the "bad ecu" (possibly a bad connection) or bad wiring with the vafc (you can rule this out IFFFF you are using the "good ecu" and the vafc,...and all is working).

(this is all general theory...not spend money on my advice unless you are thoroughly satisfied with your own observations)

--TJ