fuel pump doesnt work on prospective bike

[dfdbnb 0]

Hey guys,

I'm looking at an NC700XA for an irresistible price (friend of a friend bought from copart, decided he wants rid at any cost, sub 30k miles), but theres one main issue (the rest is minor - brakes, handlebars etc) - the fuel pump doesnt prime

he has both keys and the original ecu as well as a new ecu (its had a chunk taken out of it, but it looks like its filled with resin of some sort? cant see the pcb, im assuming its fine), bike switches on, displays and cranks, but theres no fuel pump whine

The pump cable has no voltage, all the fuses are working, im thinking its either the fuel relay, or the ecu is playing games with me - I have several questions:

1 if it isnt the ecu or pump relay, what else could be causing the fuel pump to not prime?

2 if it is the ecu, i saw a youtube video showing how a US ecu can be used on an aussie (or uk/eu HISS equipped) bike, is it possible on an NC? does anyone have US spec wiring diagrams i can use? 

 

TYIA

 

 

[DaveM59 1,623]

Do you mean the original ECU has a chunk out of it, as hacking a hole in a certain place and messing with the PCB is how theives bypass the immobiliser.
The new ECU won't work with the old keys as the transponders don't match to the HISS.
If the immobiliser isn't unlocking the LED on the dash should keep flashing when turning the ignition on.

If the original ECU is undamaged and the keys do match and there is no HISS LED on the dash then the quickest way to detect the issue is with a diagnostic tester to see if there are any stored error codes. These are fairly cheap but you need the 4 pin adaptor cable or a device specifically for Honda.

[Slowboy 22,876]

3 hours ago, DaveM59 said:

Do you mean the original ECU has a chunk out of it, as hacking a hole in a certain place and messing with the PCB is how theives bypass the immobiliser.
The new ECU won't work with the old keys as the transponders don't match to the HISS.
If the immobiliser isn't unlocking the LED on the dash should keep flashing when turning the ignition on.

If the original ECU is undamaged and the keys do match and there is no HISS LED on the dash then the quickest way to detect the issue is with a diagnostic tester to see if there are any stored error codes. These are fairly cheap but you need the 4 pin adaptor cable or a device specifically for Honda.

My thoughts also Dave. Been stolen, needs some money spent, no simple fix. Hopefully it’s not still stolen?🤔

[Andy m 25,583]

+2 Not sure how it's done (insurance databases? DVLA?) but totally agree, see if it's stolen before spending any money. If the original owner is going to come back for his stuff it's better you aren't handing him a load of unpaid for, unrequested work.

 

How though? Ring an insurance company with the VIN and claim you are worried? Plod?

 

Andy

 

 

[Rocker66 36,567]

26 minutes ago, Andy m said:

+2 Not sure how it's done (insurance databases? DVLA?) but totally agree, see if it's stolen before spending any money. If the original owner is going to come back for his stuff it's better you aren't handing him a load of unpaid for, unrequested work.

 

How though? Ring an insurance company with the VIN and claim you are worried? Plod?

 

Andy

 

 

@dfdbnb Try www.hpicheck.com or www.carcheck.co.uk 

[dfdbnb 0]

bike isnt stolen, he got it from copart, decided he wants the garage space, now wants rid at any cost - friend of a friend

the pcb looks undamaged, but i didnt check if the hiss light kept flashing aftew turning it on - might have to pop back to him and do some more tinkering.. lol

his obd scanner gave next to no errors, apart from low abs voltage (battery was dead)

ive done some research earlier, the whole system is power, ground, two signal cables from ecu to receiver? how would i test the signals and make sure the wires are good? he does have a spare receiver he bought

and if im correct, the fuel system is just ecu>relay>pump, correct?

 

ty

[MikeBike 5,087]

How do you know it wasn't stolen when listed on copart? Do you have a V5C? Maybe there should be some way of showing photos of end of vin with end of vin on v5c before forum helps people get around HISS/damaged ECU issues etc.

[Slowboy 22,876]

The reason a few of us on here have mentioned it possibly having been stolen is what you described is a classic way of disabling the HISS by damaging the ECU so it’ll start with a key. When the HISS works, it disables the fuel pump so the bike won’t start. So classic symptoms of a bike that’s been stolen with a half a**ed attempt to bypass the HISS function of the ECU. 
 

My guess is, unless it’s something simple like the pump relay or the pump itself that’s failed, it’ll need a new ECU and a visit to a Honda dealer to get the whole lot talking to each other via their diagnostic kit.

 

Not something you can do at home so far as I know. It may not turn out to be that much of a bargain……

Edited August 2 by Slowboy

[dfdbnb 0]

and here i was, thinking hiss is undefeatable by thieves..... lol

i can ask for the v5 the next time i see the bike - pretty sure copart wouldnt list a stolen bike with both keys for it...... right? btw, to clear everything up, it was bought from them as Cat X

 

are there any specialists apart from honda that can pair new keys for me?

[Andy m 25,583]

9 hours ago, dfdbnb said:

the whole system is power, ground, two signal cables from ecu to receiver? how would i test the signals and make sure the wires are good?

That's a CANBUS, although I never knew the NC used one. The hi and lo are twisted pair? 

 

You test these either by talking to any ECU's in the network that have the ability or a CANviewer. The latter is close to impossible if you don't know the system, getting a shunt resistor in the breakout that won't upset it is painful and the result is often then a thousand codes that the vehicle manufacturer invented for themselves that aren't in SAE J-1939. 

 

You can buzz out the twisted pair just to make sure they aren't open.

 

Does the fuel pump run on a bench?

 

OBD only listens in and only has to provide what the standard calls for. If nothing tells the Engine to run it'll never log an OBD fault. If it's allowed to clear the fault because something sticking happens often it won't log an OBD fault. You only know from this that it isn't a glaringly obvious thing like the fuel pump unplugged. Think of OBD as the press release not the internal discussion.

 

A visual inspection of a board only goes to far. You need a microscope to do it properly. That said, thieves aren't subtle, it's usually a hot soldering iron shoved right through.

 

Anything man makes other men can defeat. It's annoying Honda can't read the interweb, realise their work is undone so easily and switch to flammable/arsenic releasing potting compound.

 

Andy

 

 

[Slowboy 22,876]

53 minutes ago, dfdbnb said:

and here i was, thinking hiss is undefeatable by thieves..... lol

i can ask for the v5 the next time i see the bike - pretty sure copart wouldnt list a stolen bike with both keys for it...... right? btw, to clear everything up, it was bought from them as Cat X

 

are there any specialists apart from honda that can pair new keys for me?

Hopefully someone on here will know whether there is or not. In my limited experience this is a Honda dealer only thing, but there are some really good electronics specialists out there. Good luck with getting it all together.

 

PS, I see the CoPart definition of Category X is stolen/recovered with minimal damage.

Edited August 2 by Slowboy

[dfdbnb 0]

50 minutes ago, Andy m said:

That's a CANBUS, although I never knew the NC used one. The hi and lo are twisted pair? 

 

You test these either by talking to any ECU's in the network that have the ability or a CANviewer. The latter is close to impossible if you don't know the system, getting a shunt resistor in the breakout that won't upset it is painful and the result is often then a thousand codes that the vehicle manufacturer invented for themselves that aren't in SAE J-1939. 

 

You can buzz out the twisted pair just to make sure they aren't open.

 

Does the fuel pump run on a bench?

 

OBD only listens in and only has to provide what the standard calls for. If nothing tells the Engine to run it'll never log an OBD fault. If it's allowed to clear the fault because something sticking happens often it won't log an OBD fault. You only know from this that it isn't a glaringly obvious thing like the fuel pump unplugged. Think of OBD as the press release not the internal discussion.

 

A visual inspection of a board only goes to far. You need a microscope to do it properly. That said, thieves aren't subtle, it's usually a hot soldering iron shoved right through.

 

Anything man makes other men can defeat. It's annoying Honda can't read the interweb, realise their work is undone so easily and switch to flammable/arsenic releasing potting compound.

 

Andy

 

 

The damage to the pcb is minimal, the only exposed bit is the top of a capacitor - unless the ecu has multi layered pcbs with a centimetre or so of resin between them it has 0 damage 

 

Fuel pump should run, bikes done under 30k miles, I've been chasing the voltage in the wires for now 

What do you mean buzz out the twisted pair? 

[Andy m 25,583]

45 minutes ago, dfdbnb said:

 

What do you mean buzz out the twisted pair? 

Simple check for continuity. Just end to end with the meter set to buzz.

 

If it's open it's not working. Minimal resistance it's not your problem. Might read 15 OHms, the whole dots and dashes thing is based on that to set a zero point so there are sometimes shunt resistors when they get the number of nodes wrong.

 

Andy

[DaveM59 1,623]

Even if it was stolen and recovered copart would only sell it if it wasn't on the 'wanted' list any more.
I would keep the original ECU installed and use the original keys if you can be certain they are all original and a matched pair.
If there is the slightest doubt they aren't a matched pair then send the undamaged ECU to gtmotoparts in Hampshire (or similar firms) and either see if they can bypass the immobiliser or provide a set of matching keys having tested that the ECU is good.
You could try hard wiring direct to the pump to check it works and see if it starts while hard wired to be sure it's not just a dead pump, but that would be rare.

[Andy m 25,583]

Do all pumps include a bypass?

 

Old trick when stuck up the desert was to just wire the pump to an ignition feed. It'd run all the time, mostly just in a loop tank-pump-bypass-tank. EFI would put the light on but would just open it's solenoid and take what it wanted. The pump would cook if the tank wasn't full enough to soak up the heat of a pump running more than it should.

 

This was before limp modes, worrying about St.Greta's box getting soaked etc. though.

 

Never thought there's be nostalgia for Bosch EFI and 41 mpg, but I guess things aren't what they used to be!

 

Andy

[dfdbnb 0]

6 hours ago, DaveM59 said:

Even if it was stolen and recovered copart would only sell it if it wasn't on the 'wanted' list any more.
I would keep the original ECU installed and use the original keys if you can be certain they are all original and a matched pair.
If there is the slightest doubt they aren't a matched pair then send the undamaged ECU to gtmotoparts in Hampshire (or similar firms) and either see if they can bypass the immobiliser or provide a set of matching keys having tested that the ECU is good.
You could try hard wiring direct to the pump to check it works and see if it starts while hard wired to be sure it's not just a dead pump, but that would be rare.

im going to probably pop down to him and poke around a bit more - ill give gtmotoparts a call as well

as far as im aware the keys are a match - afaik they open the tank n seat as well (will need to check)

everything im doing so far is without the pump - ive been looking for 12v from the supply cable, getting 0v...

[dfdbnb 0]

Sooooooo.... update, if theres anyone left here lol
I ended up getting the bike, its been stood untouched till today - ive started reassembling the bike and tidying up the wiring - got an american ECU on the way, ive seen a couple videos on youtube of people bypassing hiss on their bikes with US ecus (which dont have it) and some wiring work

my new questions are:

The luggage box/fuel lock is broken - the key now goes in (post wd40 and some force), and turns, but only to the right about 90degs, does not go left whatsoever - can i purchase a second hand lock, disassemble both, and rebuild the "new" one with the "old" pinout? or is there a way to open it to repair it?

I need a front left cowl, the fairing that goes under the headlight, fusebox cover, battery box cover, fuel tank rubber washers, left air duct in silver - i think thats everything, where can i get these parts for cheap apart from that auction site (is anyone here breaking a bike? im in london)? also missing tons of other hardware, but i should get by with an aliexpress set of bolts (just for the fairings) and cable ties

Another question re the lock - does anyone have a photo of how the cable/s (i only have a cable for the pillion seat release - am i meant to have 2?) are arranged in the lock? workshop manual hasnt been very helpful here..
tyia