Carb problem

[Lynn Eades]

I bought a modern (improved?) needle valve assembly from a Holley carb parts supplier in the USA. I found him on epay, but do not remember who he is.
It works fine btw. Also Ron if you happen to have a vacuum / pressure gauge, try blowing in it. You probably cant move the needle? Does your float arm have a dimple worn into it? Is the pivot pin worn and floppy? If you suspect the valve is sticking, then you need to start suspecting the parts involved. Electric pumps push better than pull, as a general rule. What is your pump delivery pressure?

If you are trying to start from cold (after a time) then you needle valve is likely open already (because the petrol (or some) in the bowl has evaporated) This would mean that there is no resistance to fuel flow and yet your bowl is dry. This might be because the pump is "dry" and wont prime? Maybe you have an air leak on the suction side of the pump?
That should give you a few things to think about?
Not knowing all the details makes distance diagnosis difficult....

[Ron Pier]

Thanks Lynn. I did previously have a fuel issue that turned out to be one of the things you mentioned. After several days of messing about and rebuilding the original mechanical pump, after which I gave up and fitted the electric pump. It turn out to be a leak in the flexible pick up pipe from the tank. But I'm sure it's not that this time as the pump is delivering fuel ok, but it wasn't getting into the float chamber.

My electric pump was not expensive and I have no pressure gauge, but it's been working brilliantly up to now. What I especially like is that it primes the float chamber without churning the engine over before hand.....There is no hand primer on my unit, even if I wanted to climb in the back and remove an engine cover to do it. Ron

[Lynn Eades]

Hi Ron, I only have electric pumps (no mechanical) I have one for each tank and a change over switch at the diff pinion area.
I am wondering if you are sucking air? Each of those hoses can be leaking at either end, at the flexible connections and at any point in the flex as well as from your change over tap. That's 3 hoses and the tap, on the suction side of your pump (I think?)

[rob love]

https://daytonaparts.com/daytona-car...oat-valve.html


Found this on the net: A new design for the needle valve. I may give this a try this summer if they have parts applicable to the carb I am using.

[Ron Pier]

Lynn, my tests so far are indicating no problem with the plumbing. A good healthy flow as long as the needle doesn't stick. I've just fitted my new one, and straight away I've had to tap the carb top to free the needle.

I like the sound of the Daytona valve that Rob suggests and have emailed them to ask the availability for my Ford 94 carb.

My other thoughts are that I've seen mention of the electric pumps with a pressure gauge and wonder if I should explore this more. Maybe my cheaper pump is already losing some pressure?

Ron

[rob love]

I don't think the pressure would be the problem. The needle should fall away with the lowering of the float.
Still too cold here to be out messing with carbs, so let us know what you find from Daytona. I note they do list the applicable Ford carb kits on their site.

[Ron Pier]

Hi Rob. I had a reply from Daytona although I think they missed the point as they were giving me advice on over flooding problems.

Also they will not ship to UK or EU any more because of VAT issues?? I have asked them for a price in case you or someone else is thinking of buying one and might be inclined to buy one for me and post it over.

Regards Ron