Bedford CF help

[The Moog]

I am still struggling to get Bernard working.

 

The Symptoms - Smoke at idle, idles very badly, without choke it is <400 rpm so starts to stall. It looks like it was buring brake fluid as that dropped and the smoke was white. If I pull out the hose that runs from teh brake servo to the engine then everything is fine.

 

So far I have replaced the master brake cylinder for a new one, replaced and greased Brake Servo seals, Replaced Brake Servo itself (x2 one brand new and one nos), replaced the one way valve on the hose and checked the hose is ok. Spent over £400 so far on bits for her but still no joy

 

It is getting to the point when I have no time, money or patience for it. Anyone got any further suggestions before I bung it on ebay as a project ?

[nigel bickle]

''If you pull the servo hose off -it runs fine ''?

 

Do you plug the hole- presumably in the inlet manifold?

 

If not -you're getting a huge rush of air that would normally lean the mixture too far out to run. If however- it now runs smoothly -I'd venture chronic overfuelling.

 

If you are plugging the hole-anditruns fine-driveita little like thatto clear the engineout.You'll find the brakes heavy-no servo assistance- but it'll give it a chance to show how its really running -without potential servo input.

[Rusty Pelican]

What Nigel said , if it is overfueling then float level / needle valve would be a start , had a float " hole " once , flooded like the River Nile

[Albert Ross]

Stromberg Cd carburettor isn't it? Have you checked the diaphragm? They are known to split. Then you try to reset mixture etc. to make it run better, and it all goes a bit Pete Tong after that.

[Rusty Pelican]

Stromberg Cd carburettor isn't it? Have you checked the diaphragm? They are known to split. Then you try to reset mixture etc. to make it run better, and it all goes a bit Pete Tong after that.

These things are the spaun of Satan , SUs are much better

[scooters]

Agree strombergs are a nightmare I switched to Su in an old Volvo 145 should be easy enough to convert

[simmo]

Will I'm happy to have a look with you if you're about during the week, I've done a a bit on Strombergs and may even still have some diaphrams but to be honest in doesn't sound like that's the problem. If I can find it I have the tool for doing the mixture.

[Albert Ross]

Granted, it may not be, but it's worth a look on the fuelling side for the sake of a few screws. Also consider an inlet manifold gasket cracked or gone, as a reset of the carb under these circumstances would "cure" it until it goes again. I had a similar thing happen on a 1969 Land Rover, which would be fine at speed, but shit at idle. it was the inlet manifold cracked!

[The Moog]

I am not plugging the hole, leaving it open. Hadnt thought about carb. Bedford CF owners club thought it was brake servo, hence the money spent on it all. I have only ever dealt with FI not Carbs so a bit of a mystery to me. I havent even loooked at carb

 

Simmo that would be great. Any help is much appreciated. My missus is muttering about rubbish old cars and stuff.

[Albert Ross]

Where in the world are you? If I had enough fuel, I might have taken a trip out.

[simmo]

The Moog and myself both live in Hayes Middx but I think hes trying to escape.

 

I wasn't dissing the fuel suggestion just saying diaphram doesn't normally affect idling too much.

[The Moog]

Thanks for the offer Albert but I think that the petrol may be a bit much Donny to here under the heathrow flight path

 

I mentioned what you have said on the bedford site and they said

 

Ding! If it's a Zenith carburettor then the O-ring between the top & bottom halves being misaligned could be a likely reason.

 

Otherwise the float setting could be wrong &/or the needle valve may be so worn that it dribbles all the time, or the needle valve seating may be loose (Zenith or Weber).

 

Looking at HBOL it looks like they only came with Zenith Carbs. Might be brave and have a look at it tomorrow

[Albert Ross]

Same carb as a Land Rover 2286 from 1968 to about 1983 then. It's a regular problem with warped carb bodies....Try a place called Paddocks for a spare. Failing that, have you tried Howard at Collectors Car Parts (spares?) on Sipson Way, West Drayton? I used to go there for everything when I lived in Slough.

[The Moog]

I got the brake servo from Collector car spares. If i need more bits will wander along. A shop I want to own at some point

[Des]

Don't dismiss brake fluid being the cause of the smoke just yet, it could take a long time to burn off, your exhaust may be coated internally with the stuff and it's slowly smouldering away, could take a bit of a drive before it clears. Never tried it myself but I've been told a squirt of brake fluid down a plughole is a good form of sabotage, makes an engine appear knackered without doing any harm.

I wonder if the original servo was the source of an air leak, and the mixture has been adjusted crazy rich to compensate. You've repaired the original fault properly, now you need to undo some gits bodges, you're not the first.

[nigel bickle]

if you've left the pipe off -effectively leaving the manifold with a big hole in it -forget the brakes-they're(shortterm) out of the equation.

 

The inlet manifold will be sucking in horrendous amounts of 'unmetered' air-so it must be chronic over fuelling.

 

My initial guess is a punctured float, split diaphragm or a speck of dirt in the system there someplace.

 

Take the top off the carb- I suspect that the issue is in the float chamber.

[The Moog]

Taken off the air hose to the carb and the top butterfly flap is loose. This doesnt feel right to me and I think that it should have a spring to connect it.

Would this be right?

 

Pics Below

 

[M'coli]

That would make sense.

[nigel bickle]

You need to take the top off the carb. 4 (-6) small screws -lift it carefully so as not to damage the gasket.

 

Is the float floating -or sunk? Is there a lot of muckin the bottom?

 

Follow the fuel line in-and check the needle valve -is it stuck? Is the fuel level more than2/3 of the way up?

 

There looks like some bodgy connections on that carb- is that a garden wire linkage I can see?

The top flap is the choke. Pull the cable -it'll swivelflat. Push the cable in -vertical. As long as it does that -ignore. If it stays horizontal -it'll flood the engine (no air-too rich)

 

Hope that helps...

[The Moog]

Thanks Nigel for advice. The blokes on Bedford forum have said that it is missing the spring and also a peg stop that sorts the choke out.

 

I am going to try and track those bits down first before anything else. Any ideas of where to get one? Collector Spares in Sipson is the only one I can think of.

[Albert Ross]

If it's a Zenith 36IV, then it's the same as a Land Rover 1967-1984. Therefore anything with leaf springs. There's bound to be someone local to you with an old leafer...... knock on the door. Us Landy types are quite friendly... Don't bother with the coiler brigade, they're just a bit selfish with all their chequerplate and snorkels! I do know of a bloke nearish to you, but will have to check to see if I can release his details. Are you on Facebook? I could give you his name, and you could go from there maybe.

[The Moog]

That would be cool but sadly it is a Weber because it is a later CF just before the CF2 came out.

 

yes on fb - willybhorse nfeffer

[Albert Ross]

In which case it would be the 34ICH. As used as an "upgrade" by the glossy mag parts places for Land Rovers. Also used on Mk1 Fiesta, Crossflow RWD Escorts, and also a conversion for the 1.6 Pinto on a Cortina, Capri, Transit or Mk1 Sierra!

[nigel bickle]

Short term- just disconnect it. It'll 'rest' at vertical'; meaning you've no choke.

 

Bearing in mind it seems to be chronic overfuelling - it'll start from cold Ok ish -and run a sight better thereon. If there's no change -it isnt the choke (as I believe).

 

Whereabouts are you? If you're unhappy stripping the top off -you need an old fashioned jobbing mechanic.

Its not a time consuming or difficult jobbie -I suspect a good few of us on here would have this diagnosed/sorted in 30 mins.

[The Moog]

Found a spring that fitted so that is all happy again but you are right Nigel it is still overfuelling.

 

Simmo has offered his services so hopefully we can have a look at it.Problem is that dark nights mean it is only weekend really I can get to have a look.

 

I took the top off and looked at the float chamber etc. But it means nothing to me

[The Moog]

Fixed !

 

Simmo came round and sorted it all out for me. Seemed to be the timing and a mucky carb. Way beyond what I could have done.

[nigel bickle]

Congrats. .