Help!! - Blowing Fuse 6 - Dead Short!!

[Grizzly]

Had to get bike trailered home today . it just stopped, starter etc ok, but noticed fuel pump not running when ignition switched on.
Found fuse 6 blown, replaced with spares and all blew immediately, even with fuel pump plug at tank disconnected.
Now the bike is at home and I have a meter I've pinned it down to the the outgoing feed from the fuel pump relay. This feeds various things:-

fuel pump
valve1
valve2
timing valve

The feed from the relay is split at a solder connection buried in the loom, it still has a dead short with pump, valve1 & valve2 disconnected - well, I'm assiming valves 1&2 are the injectors? - but what and where is the timing valve - that's it's description on the wiring diags - it looks like a solenoid valve - same symbol as used for valve 1 & 2 (injectors??)
Can anyone help? things are not going well

Cheers....................Grizzly

 

[ktmmark]

Make a test light with spades that fit in the fuse holder & fit where the blown fuse goes, due to the short it will light up .
Check round the wires etc & the light will go out when you find it Saves on fuses

 

[Grizzly]

No Joy Yet !!

Hi Ktmmark,
Only wasted fuses when stuck at road-side, once home I'm using a digital multi-meter, so no fuses wasted now - I can have fuse 6 in ok as long as the fuel pump relay is out - the short is on the output side of this relay, as described in original post. I can "monitor" this circuit on the meter between the outgoing wire from the relay and the negative terminal on the battery on ohms
My urgent need at moment is to find out what/where the timing valve is?? - that's the description on the wiring diagram!. It's the only thing still connected to the part of the loom with the dead short so I need to find it to disconnect it to see if it's at fault, and if not, it must be in the loom
Has anybody had this fault before??

Cheers........................Grizzly

 

[ktmmark]

do you have lambda's as also on same feed

 

[Grizzly]

Yes It Is!

Your right, it's also on fuse 6 - on a different page!!!!! - will go and unplug it now.

cheers..............grizzly

Edit - Unplugged Lamba sensor - still same, still looking for "Timing valve"??

Cheers.................Grizzly

 

[Pip5ter]

Fuse No 6

Don't claim to know a great deal about these matters but could it be the relay itself?

 

[ktmmark]

Tried to find the relay as you say shown as a solenoid ,but no no luck sorry
Think you are going to have to inspect the loom from the relay & keep one eye on the meter suspect a wire has rubbed on the frame or fitting going to earth .
You may even come across the we can't find
Let me know how it goes

 

[Grizzly]

Hi Daleslad, relay already out, it's ok. metering/checking from output-side connection for this relay.
Ktmmark, already carefully opened up part of loom - including the bundle of splitter connections and all seems ok so far. Loath to do any more damage until I've unplugged this mystery solenoid - the timing valve??.

Cheers....................Grizzly

 

[Steptoe]

I've unplugged this mystery solenoid - the timing valve??.

:

Hall sender unit.

 

[Grizzly]

Hi Steptoe,
No, its not the hall sender unit - it's shown as that on the motronic input diagram. This "timing valve" is shown as a solenoid-operated valve - exactly the same symbol as the injectors! - and they are all supplied through fuse 6 and the fuel pump relay with +12v ( the motronic unit which controls them must control the -ve side?
I've moved/checked wiring and opened up loom a bit with no sign of short disappearing - which is unusual if its earthed against something? - so I need to get this other supply to the "timing valve" unplugged to prove if it's still the loom, or if it's the timing valve that's the problem.

Cheers.....................Grizzly

 

[Grizzly]

Sorted!!!!!

Found short at last . The "timing valve" is NOT fitted - well, not in the UK anyway?. but the connection plug for it (identical to the ones which fit onto the injectors) is tucked-up in a small recess on the rh side of the back mudguard, tied to the sub-frame .
The wire as it leaves the plug had rubbed on a sub-frame web & shorted. We still don't know know what the Timing Valve does?? - but at least we know where it would be if we had one
So Fuse 6 supplies the Fuel Pump Relay which in turn supplies a constant +12Volts when the ignition is switched on to the following:-

fuel pump
lh injector
rh injector
lamba probe
timing valve - it's not fitted. but the plug at back mudguard is still supplied.

Thank to everyone for their help

Cheers..........................Grizzly

 

[Egon]

Glad you found the problem.

Mart P and I had been wondering what that plug was for when we took his back end apart to change his clutch.

 

[ELIMINATOR]

This timing valve, would it be something the Yanks have to have fitted for emmissions? I've read on their site about owners removing them, " canisterectomy" as they are inclined to call it.

 

[Bigtwin]

This timing valve, would it be something the Yanks have to have fitted for emmissions? I've read on their site about owners removing them, " canisterectomy" as they are inclined to call it.

If it's the same thing as was fitted to the MGBs that went to the states, it's an anti run-on decice that was there to comply with emissions regulations - soulds like the same kind of thing

 

[ktmmark]

Glad it's sorted did you cut the plug off or just repair the wire