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MG Midget and Sprite Technical - Fuel pressure probs

Hi all, I'm having a problem related to fuel pressure so thought I'd see if anyone has experienced anything similar.
My Frog has a 1275 running a 40DCOE, Filter King and Facet solid state pump mounted close to the tank with a filter between tank and pump.
I've had this setup for 10+ years and never had a fuel problem.
Usually when turning on the ignition you hear the pump run (it's a knocking sound) and then after a few seconds and the pressure builds the knocking becomes quiet.
I tried to start my Frog after it hadn't moved for quite some time and I noticed the pump didn't quiet down, the car started but cut out pretty quickly and wouldn't restart (which now I know was because it ran on what was left in the carb)
There was no fuel getting to the carb, I pulled the fuel hose off the carb, filter king, checked for grit etc, put it all back together checked I was pumping fuel up the hose, all OK, car started, no problem.
After leaving it a few weeks I get the same problem. go through the same routine and get the same result.
After a few repeats I now find that if I pull the fuel hose before the filter king and run the pump until fuel comes out, then connect back to the filter king it works fine, but, even after running the pump before disconnecting the hose, it takes a second or two before fuel comes out of the hose, as if its never managing to push the fuel close to the front of the car when all connected.
I suspect the pump, but I thought that the solid state pumps either work or don't so I'm wondering what to look at now as it seems to be unable to provide the pressure required, but once 'primed' runs OK, any suggestions?

Thanks
Mark
Mark M

You may have a partial blockage in the fuel line before the pump, try removing the line on the input side of the pump and blow back into the tank with an airline. I had the same problem at one time and that cured it, I also fitted an inline filter to the input side of the pump.
Graham.
Graham P 1330 Frogeye

Makes sense, I need to check this at the weekend.
Thanks
Mark M

...and if you end up buying a new pump, buy one to the correct sepcification and ditch the filter king regulator as it's unnecessary and just something else to go wrong / adjust wrong /tinker with / worry about.
David Smith

David, Funny you should say that, I never had a filter King when I first built the engine about 20 years ago (god I'm getting old!) but when I took it to the rolling road to be setup, the operator suggested I fit one as IIRC the Weber wouldn't like too much pressure and something could go wrong (I forget what though)
I think he then setup the Filter king for me with a fuel pressure gauge after I'd bought and fitted it.
Anyone know what sort of pressure the Weber will be happy with as the Facet pumps can be bought at a rating of 1.5-2.5 PSI which no doubt is the one I already have or is the setting the Filter King is set for.

Mark
Mark M

Googling tells me 3-4 psi is good, 5 max, otherwise it can sink the floats.
Mark M

If you were in the usa, id blame the fuel, ....you simply cant let fuel set around in cars like we used to, about 4 - 6 months is tops, then all kinds of problems begin, namely gumming up of the carbs, pump and lines at hard turns....in my caes it even turned crusty after setting for a couple years

Prop
Prop

I lost a post here a couple of hours ago. Was going to say 3.5 to 4 psi as well, it's the SUs that work well with 1.5 to 3 psi.
fuel pump specs here
http://www.fuelsystem.co.uk/web-facet.pdf
David Smith

The problem is now solved and appeared to be either the fuel filter between tank and pump or a blockage in the same area.
I disconnected the pipes at the tank end, blew high pressure air back into the tank in case of a blockage and put a new filter on and it all worked perfectly. The filter was fairly grubby so I think it was this, happy days!

Mark
Mark M

This thread was discussed between 20/07/2011 and 25/07/2011

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