Fuel starvation (403)

[peterg]

I think that I have found the cause of my problem. The solder on the ferrule of the inlet to the fuel pump had failed. Just resoldered it and will refit next week.

Found it when I took off the fuel pump and cleaned it out. An easy job to do. Got a repair kit from Teesdale Garage in Nottingham.

Next job is to reassemble the reserve solenoid unit. I don't think it is worth the £200 to overhaul it. I want to lengthen the short pick up pipe to match the reserve but the plumbers merchant says brass is difficult to solder to copper. Does any one have experience of this? Are there alternative ways?

Is there an recommendation for fitting a fuel filter in the flexible pipe up to the pump or will the standard in line plastic jobbie do?

Peter

[Michael English]

Very interesting. For my 401 I'd like to start with a quick overhaul of my AC fuel pump, but before I even open the glass bowl would like to have all the gaskets in my hand. I have a Bristol workshop parts list but that only gives Bristol part numbers. It is an AC pump but it seems I need to know more before getting parts, ie is it a model U or P or F or somesuch. Does anyone happen to know which model it is & where I might get the gaskets from (I'm in Somerset). I don't seem ablew to make out its model by looking at it, and prefer not to take it off for a closer inspection ... but may have to of course.

[HughMiller]

Inracing in Nottingham does a repair kit for the Bristol fuel pump (along with a wonderful - or frightening, depending on your finances - range of other engine parts) at https://www.inracing.co.uk/RACING_CA..._Engine_Parts/.
Mine came with a variety of gaskets and sealing rings which included ones to fit my 100 series engine OK.
The kit is fairly cheap, but the postage is expensive.
Hugh

[Michael English]

Many thanks Hugh, I have emailed them.

[James McClure]

On the statement that a plumber advised that soldering brass to copper is problematic: Brass is merely copper alloyed with zinc. They solder together quite well. Plumbers use soft solder only, which will still work. Hard soldering is brazing with brass rod or even silver, and is the best as it is at a higher temp and will not decay. The copper must be very clean, as it oxidizes quite fast.

[peterg]

You are right James. VAT & postage pretty well doubled the cost.

I used plumbers solder on the ferrule and when I soldered some brake pipe into the brass pipe this evening. Not bothered about the reduced capacity as it will suck up on the reserve pipe too.

Removing the fuel pump is very simple. Disconnect the fuel pipe unions (checking that they are still intact, of course!), undo the two nuts below the pump and pull away.

Perhaps I will have a working Bristol again tomorrow. Would RTV silicon or Hylomar be better for sealing the reserve unit onto the fuel tank?

[dkleeman]

Originally Posted by peterg

Next job is to reassemble the reserve solenoid unit. I don't think it is worth the £200 to overhaul it.

What are the options for reconditioning or buying the reserve solenoid unit?

Daniel

[Michael English]

Originally Posted by dkleeman

What are the options for reconditioning or buying the reserve solenoid unit?

Daniel

In my case the original cleaned up, but it looked very delicate hair thin wiring inside the solenoid, so frightened me. As an option to fixing it properly I'd think you could take the power wire for when the solenoid is engaged and connect it to a modern electric fuel pump, but when you look at the parts that would seem a very messy solution. Frankly, I think it best to pay the £200 suggestion for a proper repair or modify the pipework to eliminate the damaged solenoid and to ensure that fuel is drawn always from the lower 'reserve' level instead of the standard higher level. After all, few if any modern cars have a reserve fuel system.

If you want to keep the reserve, then perhaps look to a manual tap system such as used on all older motorcycles, and indeed on the Goggomobil I once owned!

[dkleeman]

The manual tap is a good idea.

I have now had a go at reviving my original solenoid and it actually went quite well. After the protective cap came of by a bit of pulling, the screw cover came off with the application of heat to the cast body. Then some careful cleaning up made it all work again. We didn't go near the coil wiring which was still intact.

Daniel

Daniel

[Michael English]

When poking about in there, I imagine you may have taken a look at the petrol float? My car seems very original indeed, but I wonder about the float ... a tin can with the lid soldered on, a few scraps of brown paper on the outside, and embossed in the cap were most of the letters to read OVALTINE. The middle letters were obscured by solder!

I imagine this is not the preferred Bristol float, but its the perfect size (about 2.5" long and about 1.25" diameter) so I rather wonder if the parts bin was empty at some stage but a tin was to hand! It was leaking a little so I resoldered the joins and added part of a champagne cork for good measure.

Michael

[Stefan]

Its well worth blowing out the fuel line as well; the tanks do shed crud over the decades and old petrol gives off solid deposits. Could explain years of misfires ive had til thinking of this.

[Michael English]

Yuh, I removed my tank & washed it out with 5 litres of acetone, which was harder than it sounds. My reserach suggests that alloy tanks need no liner (steel do) but someone had put vast amounts of sealer in there, most of which had settled in the reserve area of course. I got flakes & chunks out but some remained even after 2 weeks of this cleaning.

I blew out the lines by mouth & tyre compressor, probably not very well. Rebuilt the fuel pump, cleaned the gauze filters in the pump & to each carb but did not strip the carbs. New coil, condensor, contacts, leads, plugs & plug caps.

It fires up better, and runs sort of OK to about 60mph but gets pretty fluttery then, misfires a bit, smokes too much & the plugs oil so I have improved things but not fixed, dammit. The oil makes me feel my next task is a compression test to see if I can work out, is it rings or is it valves? Great.