Mystery Brown Wire

[Ecopod]

Good morning,

I have one of the beloved 'won't start' issues. Drove approx 70 miles home with no issue then two days later will not start. Cranks well until battery goes dead. Have cleaned earth strap / engine block earth / all wires / changed rotor arm / changed distributor / checked sparks / good battery power. There is one mystery brown wire that is not attached and I was hoping someone could identify this (although it may have always been disconnected - trying to rule out electrical before moving to fuel).

Board attachment quota reached so couldn't attach picture - see twitter link - it is the brown wire with round connector just above distributor cap.

https://twitter.com/morriceman/status/6 ... 8314881024" onclick="window.open(this.href);return false;

Many thanks for looking and hopefully someone can help.

[itchyfeet]

Brown wires are earth or ground or body, the only exception are the oil pressure switches over the engine, these are switched ground.

Can't see the wire you mean, are you sure it's brown dirty wires can look different colours.

[itchyfeet]

got the wrong dizzy on that, you should have a single vac unit dizzy you have a dual vac unit dizzy

chuck a table spoon of petrol down carb, see if it fires

[Ecopod]

Hi itchyfeet,

Thanks for quick replies and knowledge. Got some time this afternoon so will go and check wire colour - have posted close up pic. I'll put old dizzy back on, new one came with service pack.

https://twitter.com/morriceman/status/6 ... 8839028736" onclick="window.open(this.href);return false;

Cheers.

[itchyfeet]

follow it, there should be an earth connection to the left hand head that comes from the ignition module via the loom, as it's brown earth it anyway to the head.

you can see it in this pic

[Ecopod]

Thanks again itchyfeet,

I now know it is fuel related. Earthed brown cable and it made no difference.

Chucked some fuel down carb and it fired for a second. Chucked bit more down and it ran for couple of seconds. Now need to go and read about T25 carb cleaning / fuel supply (bit of a coincidence as I've just had to clean out carbs on my old CB750). With any luck the electrics will be in better nick now.

Many thanks for help and taking time to answer.

[itchyfeet]

check fuel flow is the quickest way to showing if its fuel delivery or carb.
disconnect coil so you get no sparks and take the fuel pipe off at the carb, thats the pipe from the pump, point that into a jar and get somebody to crank the engine, you should get healthy squirts of petrol (fire extinguisher handy just incase)
also while the pipe is off check the tiny conical filter in the pipe, need a large self tapping screw just twisted in gently to pull it out.

http://m.youtube.com/watch?v=kFRjMOtNuRo" onclick="window.open(this.href);return false;

[Ecopod]

Hello and thanks again itchyfeet.

Finally got back around to it this afternoon and this is where I am.

Changed both inline filters - one near tank was full of crud - one in engine bay was much better but petrol still discoloured. I also removed the small conical filter (thanks for tip) and it also had some debris in it. Everything all nice and clean but seem to be having a problem persuading petrol back through the system. First filter has filled up nicely but second filter (in engine bay) remains bone dry. Is there a bleeding the petrol through trick I'm missing.

Should add so far I've just been turning her over to try and pull petrol through.

Should double add just about to order new fuel pump etc as there doesn't seem to be much left it can be.

Cheers.

[jrt]

Afternoon, I changed the fuel pump/ filters and lines the other month and had a right job to get it going, a bit of fuel down the carb and a few cranks and it soon fired up.
Do you have a manual fuel pump and if so have you removed it and tried it by hand to see if it's sucking the fuel through ?
David

[Smiffo]

follow it, there should be an earth connection to the left hand head that comes from the ignition module via the loom, as it's brown earth it anyway to the head.

you can see it in this pic

What's that in the bottom right of this pic Itchy?

[Ecopod]

Hi JRT and thanks for responding.

I tried the fuel down carb etc and cranked for about 10 mins in total but to no avail.

It is a manual pump but I'll probably just wait on new one now as it'll be here on Tuesday and I'm busy Monday in any case.

One thing I did notice when checking pipes and blowing air through was that the pipe between first and second filters is narrower (with connection to thicker pipe to affix to filters), do you happen to know if this is normal.

Thanks.

[CovKid]

If it doesn't try to fire with fuel down carb, theres no spark.

[Ecopod]

Sorry wasn't clear - it fires fine with fuel in carb.

[jrt]

re the pipe dimensions, I think most people have a few different diameter fuel lines from front to back. I've got 8mm from the tank to the filter[ under the van] then I think a 6mm rigid under the van into the engine bay where it goes back to 8mm- or it might be 7mm-not 100% sure.
I don't have a second filter in the engine bay. All the correct lines can be bought from Brickwerks in a nice kit with everything you need.
If you take off the fuel pump[dead easy] and manually work it from underneath you'll be able to see/hear/feel if its sucking properly.
David

[Ecopod]

Hello again JRT.

Thanks for taking time to explain re pipe sizes, that is same as mine so at least that all seems okay.

I'll get back to it on Tuesday, hopefully get back up and running soon.

Chers.