Fuel Cut Off Solenoid

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tobydog
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Re: Fuel Cut Off Solenoid

Post by tobydog »

mrbodly wrote:I've just noticed on Boxy's pic, the outlet on the back (towards cab) of the air filter housing has a pipe connected to it, mine does not, it is just open. Should I have a pipe connected?
I've never had that pipe so I blanked the hole off in the air box. Where is the pipe meant to be connected to?
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BOXY
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Re: Fuel Cut Off Solenoid

Post by BOXY »

I've just noticed on Boxy's pic, the outlet on the back (towards cab) of the air filter housing has a pipe connected to it, mine does not, it is just open. Should I have a pipe connected?

I don't think it's supposed to be connected to anything. I had a spare piece of flexi-hose in the tool-box so I routed it out through the bulkhead. My thinking was it was better to be sucking in cold air, rather than hot air from the engine bay.
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Re: Fuel Cut Off Solenoid

Post by mrbodly »

Hi all

Just to update, the upper gasket on the left hand carb had been poorly fitted, I replaced it and all seems well.

Cheers
Myles

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Re: Fuel Cut Off Solenoid

Post by mrbodly »

Hi All

I spoke too soon. Now the van won't idle at all, it'll start no problem and run if you keep the revs up, as soon as you take your foot off the throttle it dies.

Over the last week I replaced the solenoid trigger wire, van now starts on the button which is good! Replaced the idle valve and also the servo vacuum hose (after melting the old one). Thought maybe the new servo hose was the cause of my problems, so removed from carb and blocked off but no change.

Just replaced the fuel filter, there was a small amount of crud in the old one. This hasn't made a difference.

Was thinking of buying a £30 empi carb rebuild kit to see if this makes a difference.

Need to get this sorted so I can get the thing MOT'd and back on the road, so any advice gratefully received.

Cheers
Myles

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BOXY
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Re: Fuel Cut Off Solenoid

Post by BOXY »

Sound like an air leak, or one of the fuel solenoids isn't getting 12 volts.
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Re: Fuel Cut Off Solenoid

Post by kevtherev »

Is the mixture ok now that you have been busy repairing things?
If it's been set up to run with an air leak, it won't like it now you've stopped it
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Re: Fuel Cut Off Solenoid

Post by mrbodly »

Fuel solenoids are working fine. Does anyone know what the standard baseline settings for the mixture setup are?

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Re: Fuel Cut Off Solenoid

Post by kevtherev »

mrbodly wrote:Fuel solenoids are working fine. Does anyone know what the standard baseline settings for the mixture setup are?

Cheers
you need a gas analyser for that
Any MOT testing station can do that for you.
the pass % is a good start point.
But ideally CO content @ idle 0.±.3 % volume
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Re: Fuel Cut Off Solenoid

Post by kevtherev »

Ignition timing 5°±1° ATDC with vacuum, but when setting ignition timing on vehicles with digital idle stabilisation, the two connectors to the unit must be plugged together.

Mechanical ignition advance checks 0°-1° @ 1150RPM w/o vacuum and basic timing
9°-13° @1600RPM w/o vacuum and basic timing
21°-25° @3400RPM w/o vacuum and basic timing

Disconnect engine crankcase breather and plug on side of air cleaner.
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Re: Fuel Cut Off Solenoid

Post by mrbodly »

Merry Christmas everyone.

I've managed to get the van idling smoothly at approx 900rpm. I adjusted the mixture screw and also the stop screw on the throttle.

My carbs are in need of a refurb though as there is some lateral movement in the throttle shafts (a po has used silicone as a temp fix). Does anyone know where I can get them refurbed and approx cost?

Cheers
Myles

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Re: Fuel Cut Off Solenoid

Post by Merrsh1 »

Just a question about this solenoid. On my van its been blanked off and is very 'wobbly'. I can jiggle it with 1 finger with 10mm movement... Image below...

Image

No issues with the van but is this something to worry about? I tried screwing it in but it doesn't seem to want to go in and I didn't want to force things till asking on here :D

Also the idle stabilising unit is completely disconnected too...
Aircooled 2.0 1981

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Re: Fuel Cut Off Solenoid

Post by bigherb »

Merrsh1 wrote:Just a question about this solenoid. On my van its been blanked off and is very 'wobbly'. I can jiggle it with 1 finger with 10mm movement... Image below...

Image

No issues with the van but is this something to worry about? I tried screwing it in but it doesn't seem to want to go in and I didn't want to force things till asking on here :D

Also the idle stabilising unit is completely disconnected too...

I expect the tread in the carb has worn out, usually caused by the valve coming loose and rattling around in the thread from the vibration of the engine. You can either source another carb top, glue the valve in with some chemical metal or remove the valve and blank the hole.
And the wiring to the valves and chokes is too thick, it should be 0.5mm2 cable as it is sacrificial wiring if there is a short (it is usually the chokes short) the thin wire burns out rather than the main loom.
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Re: Fuel Cut Off Solenoid

Post by Merrsh1 »

bigherb wrote:I expect the tread in the carb has worn out, usually caused by the valve coming loose and rattling around in the thread from the vibration of the engine. You can either source another carb top, glue the valve in with some chemical metal or remove the valve and blank the hole.
And the wiring to the valves and chokes is too thick, it should be 0.5mm2 cable as it is sacrificial wiring if there is a short (it is usually the chokes short) the thin wire burns out rather than the main loom.

Thanks. What are the downsides / upsides of not having this connected? I'm guessing it should go to the idle stabilising unit but that isn't connected either...

I'm on replacing the wire, I was going for like for like but I'll get the thinner stuff now...
Aircooled 2.0 1981

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bigherb
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Re: Fuel Cut Off Solenoid

Post by bigherb »

Merrsh1 wrote: Thanks. What are the downsides / upsides of not having this connected? I'm guessing it should go to the idle stabilising unit but that isn't connected either...
Without the valve, the engine may run on a bit when you switch it off.
The idling stabiliser is often just bypassed when they fail, just means the idling is not as smooth.
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Re: Fuel Cut Off Solenoid

Post by Merrsh1 »

bigherb wrote:
Merrsh1 wrote: Thanks. What are the downsides / upsides of not having this connected? I'm guessing it should go to the idle stabilising unit but that isn't connected either...
Without the valve, the engine may run on a bit when you switch it off.
The idling stabiliser is often just bypassed when they fail, just means the idling is not as smooth.

Cheers.

>> Without the valve, the engine may run on a bit when you switch it off.

That's never happened so I'm guessing I don't need to worry.

>> The idling stabiliser is often just bypassed when they fail, just means the idling is not as smooth

Yup, it can be lumpy on start but a blip of the throttle usually resolves it. :ok
Aircooled 2.0 1981

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