Tipidave Posted April 3, 2021 Report Share Posted April 3, 2021 My recently fitted new fuel pump has failed within a few miles and i really do not want to exchange it for another. The quality isn’t good. Despite assurances from the vendor. My previous (non original)fuel pump was pushing out way too high a pressure. So I have taken the spring out of the new pump and fitted it to the old. Still it is pushing out 4 psi which is just enough that after I switch off it slowly leaks some fuel into the carb throat and out of the spindle and on to the manifold. It does this when cold so is not related to the temperature. I have gently tamped the float valve to ensure a good seat and believe it too be good. I am trying to get hold of an original ac delco pump in order to get the pressure down to a level that is tolerated by the valve in the carb. Does anyone else know of anyone who is selling a good quality replacement part with the correct rating? Or where i can get a correctly specified spring? or should i be considering a fuel cut off solenoid? In all other respects the car is running beautifully at the moment but I am not happy to have the garage reeking of fuel and do not want to drive it with this problem. As ever your advice gratefully received. Link to comment Share on other sites More sharing options...
johny Posted April 3, 2021 Report Share Posted April 3, 2021 Im surprised at this problem because normally the float valve should hold the level in the chamber well below the overflow and jet levels. There should be plenty of capacity for a little extra after stopping as the volume of fuel to be released is minimal (liquid being essential non compressible). Most systems lose this pressure pretty quickly either into the carb reservoir or back through the fuel pumps two non return valves... Link to comment Share on other sites More sharing options...
Tipidave Posted April 3, 2021 Author Report Share Posted April 3, 2021 The pressure from the pump alone is too high... so it has an adjustable pressure reducing filter in line. I think that the fuel on the high pressure side is bleeding over when stopped.it isn’t a huge volume but any is too much ! Link to comment Share on other sites More sharing options...
johny Posted April 3, 2021 Report Share Posted April 3, 2021 I dont know your type of carb but are you sure the float is good and the level set correctly because as I say there should be enough space above the float level in the reservoir to accomodate the excess to depressurise the system... Link to comment Share on other sites More sharing options...
Tipidave Posted April 3, 2021 Author Report Share Posted April 3, 2021 The carb is the b30 solex. The only adjustment to float level is the thickness of the washers that sits under the float valve. I have experimented with thicker but no difference. Also tried clamping off the fuel hose before carb upon stopping and that did stop any leaking. Pretty sure it is all down to not having a correctly regulated fuel pump. Hence my request for suggested known good suppliers and or a suitable source of replacement springs. Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 3, 2021 Report Share Posted April 3, 2021 this is a B30 type downdraft solex on a 1147 its a bit daft springs are not in the repair kits ....nuts there are a few old glass top ex triumphs on the bay at least they will have the correct pressure but most glass tops were on the 6 cly and cant compare the fit ona 4 cyl https://www.ebay.co.uk/itm/Triumph-2000-Mk2-Fuel-Pump/224409300499?hash=item343fd62e13:g:VJwAAOSwjhtf~xxB Link to comment Share on other sites More sharing options...
johny Posted April 3, 2021 Report Share Posted April 3, 2021 Float good? If they have a leak they fill with fuel up to the puncture so then can sit lower and operate the valve later. It would mean the running level in the chamber will be high and the fuel mixture too rich but maybe this has been compensated for... Link to comment Share on other sites More sharing options...
Tipidave Posted April 3, 2021 Author Report Share Posted April 3, 2021 I did consider this... the float was tested and found good. There is definitely a possibility that the float sits slightly low if the modern fuel has a lower specific gravity than the old fuels... and I did find reference to this in an old solex manual which specified different weights of float for differing fuel qualities. As previously stated I have experimented with lowering the valve with an additional washer but it made no improvement. I remain convinced that this is all down to the wrong fuel pump pressure, but do not yet have the means to correct it. Link to comment Share on other sites More sharing options...
johny Posted April 3, 2021 Report Share Posted April 3, 2021 Well its a bit drastic but as you have a spare spring is it worth progressively cutting coil off it to reduce the force it applies to the pump diaphragm? Obviously you cant make the spring too short as its got to always be compressed slightly. Alternatively it looks like the spring sits on two washers and possibly one can be removed to reduce the tension slightly... Link to comment Share on other sites More sharing options...
Colin Lindsay Posted April 4, 2021 Report Share Posted April 4, 2021 I find it strange that two pumps are causing the same problem; this points to something other than the pump being at fault. If you want to try a different pump pm me, I've refurbished half a dozen of them over Lockdown and can send you one to try. Link to comment Share on other sites More sharing options...
johny Posted April 4, 2021 Report Share Posted April 4, 2021 Agree Colin, but looking at this carb and its float design seems it might be really sensitive to pump pressure... Link to comment Share on other sites More sharing options...
Tipidave Posted April 4, 2021 Author Report Share Posted April 4, 2021 It isn’t really two pumps causing the same... the new pump I installed was observed to be outputting 4psi which was a vast improvement of the 9-10 from the original. The over flow problem was not entirely sorted but much improved. This fuel pump failed after just a few miles and upon inspection was always destined to do so... just not of a good enough quality. so I fitted the original ( still a replacement and not from the sixties) back on for time being with the spring out of the new one. I haven’t measured the output pressure but it was back to its old trick. I am hoping that if I can get a pump with 1. 5 psi output or there abouts all will be well again. Just not sure how to source such a pump... but looks like Colin can help👍👍👍 Link to comment Share on other sites More sharing options...
Paul H Posted April 4, 2021 Report Share Posted April 4, 2021 42 minutes ago, Tipidave said: It isn’t really two pumps causing the same... the new pump I installed was observed to be outputting 4psi which was a vast improvement of the 9-10 from the original. The over flow problem was not entirely sorted but much improved. This fuel pump failed after just a few miles and upon inspection was always destined to do so... just not of a good enough quality. so I fitted the original ( still a replacement and not from the sixties) back on for time being with the spring out of the new one. I haven’t measured the output pressure but it was back to its old trick. I am hoping that if I can get a pump with 1. 5 psi output or there abouts all will be well again. Just not sure how to source such a pump... but looks like Colin can help👍👍👍 I’ve fitted a Huco which is suction pump and fitted in the engine bay in my Vitesse The psi is 2.2 and serves 2 Strombergs . More details if you need them here’s the spec , ignore the price as they available cheaper https://www.ebay.co.uk/itm/Electric-14-V-2-2-PSI-0-15-bar-Low-Pressure-Fuel-Pump-HUCO-133010-Kit-Car-/254645067130?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338268676&toolid=10044&customid=CjwKCAjwx6WDBhBQEiwA_dP8rYUdi9jvfIaLiYEixX3Vvd2GkC-mtN8p0ZPcg5D9U5gCLBqkg7nlIxoCjHkQAvD_BwE Paul Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 4, 2021 Report Share Posted April 4, 2021 I think whilst its a good few ££ it is made to a defined specification that suits carbs and may be a good way to proceed Pete Link to comment Share on other sites More sharing options...
Gully Posted April 4, 2021 Report Share Posted April 4, 2021 Best price seems to be around £52.99 with free postage. Gully Link to comment Share on other sites More sharing options...
Paul H Posted April 4, 2021 Report Share Posted April 4, 2021 43 minutes ago, Gully said: Best price seems to be around £52.99 with free postage. Gully You would need one of these inertia switches https://www.ebay.co.uk/itm/First-Inertia-Switch-Vehicle-Crash-Sensor-Ignition-Electric-Fuel-Pump-P4A2-/393117141535? Paul Link to comment Share on other sites More sharing options...
Paul H Posted April 5, 2021 Report Share Posted April 5, 2021 10 hours ago, Gully said: Best price seems to be around £52.99 with free postage. Gully If the Huco trial failed to solve the carb issue there’s a strong second hand value which should realise £30 plus Paul Link to comment Share on other sites More sharing options...
Tipidave Posted April 5, 2021 Author Report Share Posted April 5, 2021 Thanks for this suggestion. Colin is going to send me a known good pump to try. At least this way i can be sure of the diagnosis. Link to comment Share on other sites More sharing options...
Tipidave Posted April 8, 2021 Author Report Share Posted April 8, 2021 Just fitted an original old fuel pump that was kindly sent by a member for me to try. I was astonished to feel just how much lighter the spring Mechanism is on this original pump. I do not understand why it is seemingly impossible to buy a correctly rated replacement? haven’t been out for a test test run but so far looking good and no whiff of petrol in the garage. thanks for all the help and advice👍👍 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted April 8, 2021 Report Share Posted April 8, 2021 Chinese whispers at work dont use a specification just fake the shape that'l work Pete Link to comment Share on other sites More sharing options...
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