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Non return valve
Posted: Mon Sep 18, 2023 7:43 pm
by alfadave
My Sud has the original type mechanical fuel pump.
If the car is left unused for over a week, fuel drains back into the tank, and starting can be difficult. Battery is ok.
I've tried easy start, and also taking the plugs out and operating the starter to get fuel through, but a bit of a pain.
I fitted a non return valve at the tank, and was ok for a bit until it failed closed!
I put a straight connector in place of it.
A decent, reliable NR valve would be a good fix. So would an electric pump, but I don't want the cost/ hassle.
Anyone know of a decent 8mm NR valve?
Re: Non return valve
Posted: Mon Sep 18, 2023 8:28 pm
by dave.armstrong
I fitted a non return valve but then ended up putting on an electric fuel pump
Re: Non return valve
Posted: Mon Sep 18, 2023 11:35 pm
by Sud 145
I crank over for 10 sec, then 3 pumps on the throttle and job's normally a goodun.
Re: Non return valve
Posted: Tue Sep 19, 2023 12:58 pm
by Alfastrut
Have you tried a new fuel pump . My 33 is better since I fitted one . It's not perfect but better.
Re: Non return valve
Posted: Tue Sep 19, 2023 7:26 pm
by alfadave
Just fitted a new one!
Re: Non return valve
Posted: Tue Sep 19, 2023 9:38 pm
by StescoG66
I fitted a low pressure (2.5-4psi) bravex electric fuel pump. Not expensive and seems good. Starting is a doddle
Re: Non return valve
Posted: Wed Sep 20, 2023 8:16 pm
by KevJTD
The trouble is nowadays it's hard to work out what is a quality part and what is trash, eBay is a minefield and just picking a more expensive part isn't always the answer as some companies just charge more for inferior parts.
An elecrtic pump is a good solution, best with carbs having a return line even with the low pressure pumps.
Car Builder Solutions would be a good source to get a valve from, far more likely to use a good quality part as they are more likely to give a warranty with it so won't want parts getting sent back, for the hassle and the loss of reputation.
This one has a sprung diaphram which appears to be able to be taken apart, handy to clean it every now and again. Some cheaper ones maybe have just a steel ball inside which is supposed to stop backflow.
https://www.carbuilder.com/uk/aluminium ... -valve-8mm
Re: Non return valve
Posted: Wed Sep 20, 2023 8:58 pm
by dave.armstrong
There lots of cheap electric fuel pumps on the market but bought a pacet one. Got the impact kill switch from some company like car builder. Didn't want it to keep pumping fuel if I crashed

Re: Non return valve
Posted: Thu Sep 21, 2023 12:01 pm
by alfadave
My old fuel pump gave up the ghost a few weeks ago, so I replaced it with a new one I had here.
Just left the car for a week, and have just done the "foot on clutch, turn over for 10 secs, pump the pedal twice" technique.
Faltered for a bit, then started.
Seems the old pump was slowly on the way out?
Re: Non return valve
Posted: Thu Sep 21, 2023 7:13 pm
by Sprint88qv
Interesting…. Why foot on clutch? If it’s obvious… it’s been a long week, that’s my excuse

Re: Non return valve
Posted: Thu Sep 21, 2023 8:34 pm
by Alfastrut
I always leave my sud in gear when parked just incase the handbrake fails. The 147 was a little different. If it was frosty out I'd leave it in gear with the handbrake off .
Re: Non return valve
Posted: Thu Sep 21, 2023 8:54 pm
by Sud 145
Sprint88qv wrote: ↑Thu Sep 21, 2023 7:13 pm
Interesting…. Why foot on clutch? If it’s obvious… it’s been a long week, that’s my excuse
I've always done it, removes any chance of drag and starting in gear.
Re: Non return valve
Posted: Thu Sep 21, 2023 9:21 pm
by alfadave
Foot on clutch means less load on the starter.
Even if you are in neutral the gearbox layshaft is still turning
Re: Non return valve
Posted: Thu Sep 21, 2023 9:27 pm
by alfadave
Correction.
Mainshaft is still turning, but no gears are engaged.
Re: Non return valve
Posted: Thu Sep 21, 2023 9:57 pm
by Sprint88qv
Ah, ok, that makes sense. Cheers
