ecu or injection fault. nearly new bike

[Guest Wheelnut]

Hi, wonder if anyone can help. I bought my nc700x brand new in april, it only has about 800mls on it. Yesterday i stripped off the plastic panels and luggage compartment to investigate the posibility of making a better seat for long distance touring. I also removed the steel braket which supports the injection pump and holds what I think is the ecu. I disconected a few multiplugs to do that. On reasembly, the engine dosent run. If I flick the red kill switch off for 10 secs then on again, the bike runs for bout 5secs. Another weird thing is that the side stand being down used to stop engine being cranked over by starter,,,, now the bike will crank with stand deployed. Have obviously rechecked all multiplugs. Is it wrong to disconect and reconect plugs? I did it with ignition off obviously. Does it have to be reprogrammed or something? Thanks. 

[Juggler 107]

my dct can be cranked at any sidestand position. it only cuts off if bike in gear or drive mode. regarding the rest - if the bike were running fine prior disassembly - it is most likely your fault. and btw - ALWAYS disconnect ground(-) battery terminal if you mess with electrics!

now, if bike is running then shuts down also check fuel hoses, you could bend it or twisted it in some way.

it is good idea to clean connectors with special fluid, but before doing this check all fuses and relays.

Edited July 11, 2015 by Juggler

[Guest bonekicker]

Martin what have you done? I am sure Fred and other top class forum members will come to your rescue--we all learn by mistakes--electronics are a really weird science and you have to be really clever to understand was as gone wrong--as Vlad says before doing anything electrical disconnect the battery terminals.

 

Please let us all know what the fault was when it is rectified  

[fred_jb 10,269]

It is weird that it will run for 5 secs after the kill switch is operated.  It is either getting no more fuel after the 5 secs or the ignition system is stopping - I would tend towards the latter as the kill switch appears to reset it.

 

I've no idea what could be causing this, but you can sometimes get weird things happening if the system is poorly earthed.   Did you remove any big chunky earth cables bolted to any bits of metalwork, such as the steel bracket holding the injection pump, or around the battery area? Are you sure any such cables are back and tightened up properly (at both ends), and that you haven't put any insulating washers or grease on them?

 

You may need to take it all apart again and make sure that none of the contacts in the multi-way connectors have been bent over such that they are not contacting their opposite numbers, and that there is no debris which could be shorting anything out.

 

Fred

Edited July 11, 2015 by fred_jb

[fred_jb 10,269]

Another possibility is that a vital sensor connection is not making proper contact - it's possible the ECU will wait for 5 secs to see if it comes online and if not will then shut down.

 

Fred

[kayz1 2,928]

What Fred said::

 

  ****You may need to take it all apart again and make sure that none of the contacts in the multi-way connectors have been bent over such that they are not contacting their opposite numbers, and that there is no debris which could be shorting anything out.****

 

 

Also: i have had one of the multi plugs push out a pin as i tried to mate them together...took ages to trace that one..

Lyn.

PS: not on an NC thou.

[djsb 493]

Does the instrument panel/speedo go through it's POST procedure (Power On Self Test where the warning lights flash up and all the segments of the LCD are shown momentarily)? Can you hear the fuel pump running for a while? Maybe the fuel pump is not pressurizing the system properly and that's why it shuts down after a few seconds. Maybe on of the plugs for the injectors wasn't pushed in properly. You need to make a checklist for yourself (do you have the workshop manual?) and then work through it methodically and slowly.

Edited July 11, 2015 by djsb

[Guest Wheelnut]

Wow, thanks for all the speedy replies.......... Yes ,I realise it must be something Ive done wrong......

The lights on lcd dash all seem normal display,...... Big earth cable is definately fine, yes I did remove it, but replaced it. Can hear fuel pump priming as normal. Have taken it apart 4 times, all plugs look good. Fuel hoses look fine where I can see them. Is it wrong to disconect and reconect plugs? I did it with ignition off obviously. Does it have to be reprogrammed or something? Thanks. 

[Guest Wheelnut]

Forgot to say, there is one multiplug which goes into the base of the tub and dosent seem to connect to anything in there?????

Is it for plugging an accesory into???? Or a diagnostic point???

[djsb 493]

Have you tried disconnecting the battery, leaving it disconnected for a while and then reconnecting it?

[fred_jb 10,269]

Forgot to say, there is one multiplug which goes into the base of the tub and dosent seem to connect to anything in there?????

Is it for plugging an accesory into???? Or a diagnostic point???

Is it a red 4 way plug?  If so it is most likely the diagnostics port.

 

Fred

[fred_jb 10,269]

Have you tried disconnecting the battery, leaving it disconnected for a while and then reconnecting it?

Good idea - if you've upset the ECU by unplugging it while the battery was still connected, this might sort it.  As someone else said - you should always disconnect the battery when doing this sort of work.

 

Fred

[Guest Wheelnut]

Yes, i did try disconecting the battery for a couple hours, no joy.

 

Its a white plug, bout 4 or 5 wires from memory.

[fred_jb 10,269]

From the manual there appears to be a CKP (crank position sensor) and bank angle sensor in the area you were working - as you have a spare connector, are sure these have been reconnected?

 

Fred

 

Edit - it appears there is also something called a VS sensor.

Edited July 11, 2015 by fred_jb

[fred_jb 10,269]

OK - I think I know what your spare connector could be - it is probably the accessories connector which the optional sub-harness plugs into.   This slots into a dummy socket/recess in the lower left side of the frunk body, pretty much at the rear left corner.   It comes off the main wiring loom just above the left frame tube.

 

Fred

Edited July 11, 2015 by fred_jb

[Guest Wheelnut]

Ah yes, thats what I thought it must be, ...... Yes, it locates exactly as you described Fred.  So no fault with that then. Still a mystery.

BTW, your fuel figure of 67mpg could be better, Ive been getting 89mpg regularly, cruising at about 65mph usually.

[embee 7,288]

...

Fred

 

Edit - it appears there is also something called a VS sensor.

That's the vehicle speed sensor (3 wires, gnd, supply, and signal to instruments=VSP), sensor is in gearbox.

[fred_jb 10,269]

Ah yes, thats what I thought it must be, ...... Yes, it locates exactly as you described Fred.  So no fault with that then. Still a mystery.

BTW, your fuel figure of 67mpg could be better, Ive been getting 89mpg regularly, cruising at about 65mph usually.

Yes it seems that I am in the minority in not getting 70-80 mpg figures.   Don't know why, maybe I'm just a bit over enthusiastic on the back roads (S mode and frequently manually changing down for bends and overtakes) and riding at 80-ish on dual carriageways.  Not too worried to be honest - I don't commute on the bike and bought it just for fun, so I'm not going to ride for economy.

 

Fred

Edited July 11, 2015 by fred_jb

[embee 7,288]

Martin, a couple of questions to try to isolate the issue. Just trying to understand what it is and isn't doing to be able to guess at what system isn't operating correctly.

1 - when you turn on ignition with kill switch in "run" position, does the fuel pump run for approx. 2sec then stop (as normal)?

2 - does the HISS light go out?

3 - does the MIL (check engine) light stay on or blink? Do you get the neutral light on? Do you get the oil pressure light on?

4 - when you press the starter does the engine crank on the button but not fire, or does it just not crank? (note - our US cousins use the term "turn over" to mean what I would refer to as "start", i.e. crank fire and run, so I'll separate the terms). Does it crank and fire but not sustain running?

5 - when you do the kill switch "reset", does it crank fire and run normally or not normally? When it stops after around 5sec as you describe, does it stop dead or falter and stutter and eventually stop?

 

I've been looking through the manual and wiring diagram but can't come up with anything obvious yet.

[Guest RobF]

Yes it seems that I am in the minority in not getting 70-80 mpg figures. Don't know why, maybe I'm just a bit over enthusiastic on the back roads (S mode and frequently manually changing down for bends and overtakes) and riding at 80-ish on dual carriageways. Not too worried to be honest - I don't commute on the bike and bought it just for fun, so I'm not going to ride for economy.

Fred

Must be our leicestershire roads Fred. My mpg matches yours Edited July 12, 2015 by RobF

[Tex 36,817]

The engine starts and runs for a few seconds then dies? And repeats this every time it's switched on? Then it sounds as though the fuel pump is not being 'fed' (power) properly. Turning the ignition on will 'prime' the pump. And give enough fuel to run for a few moments. Investigate all wiring connectors related to the fuel pump and fuel pump relay.

[Guest Wheelnut]

I FIXED IT  . Fred, you gave me a clue, you said there is a bank angle sensor..... I had refitted that upside down,,,,, bike thought it was laying on ground , fuel cuts off.  It actually has an arrow and up marked on it feintly,,,, I should have wore my glasses.  . 

Can I have the muppet of the month award now please.

[Guest Wheelnut]

Thanks to everyone who helped out.

[Guest Wheelnut]

I removed these components to investigate altering the seating. I bought the NC as I saw it had a low engine height... I am going to modify it into a recumbent motorcycle. This greatly reduces aerodynamic drag,,,, bike can be geared higher, Recon I can get near 140mpg with full fairings.

The good news is that this braket that is in the way of my plan, can be removed, ecu and bank sensor resited and injection pump supported with a new lower braket which I will fabricate. Shall do the work over the winter

[embee 7,288]

 

Can I have the muppet of the month award now please.

Yes.

 

 

Glad it's fixed, another one to file away under "strange behaviour".