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MG Midget and Sprite Technical - No Fuel Help
|Hi All |
I have a 1500 79 midget, it will not start and i found the fuel was not getting through to the carbs. I have replaced the fuel pump and it is not pulling fuel from the tank. When i take the tank supply off and put my finger over the pump intake there apears to be no suction. I have read the haynes manual and it is as normal less than useful, has anyone had this problem before?
|This seems to be a common problem with the mechanical pumps as they age. The modern replacements are no better - they have a nasty habit of shearing off the actuating arm (cheap nasty Chinese steel pressings methinks).|
Your best bet is to fit an electric pump such as a Facet Solid State or even a Midget 1275/MGB pump.
|I would follow Deb's advice & go with an electric pump.|
I learned the hard way that there were 2 different pumps that were used on the 1500 engine, of course when I ordered the pump, I got the wrong one & had a problem like you're describing. I sent it back & got the correct one, it works, BUT, I still plan to install an electric just because of what Deb said about the Chinese quality replacement parts we're getting these days.
Thanks for the post, I'll order a Facet (they're VERY easy to install) this weekend, it was just one of those things I'd planned to do, but somehow got on the back burner.
Thanks again for the reminder.
Chinese parts have sure improved my troubleshooting skills...
|Dave Rhine ('78 1500)|
|YW Dave, :)|
|If you change over to an electric pump do you need a pressure regulator and fuel cut-off switch?|
|Another down-side of the mechanical pump in the 1500 is if your car has stood for a few days then the carbs need re-filling before it will fire. And this means cranking the whole heavy engine for quite a bit just to operate the fuel pump.|
|"If you change over to an electric pump do you need a pressure regulator and fuel cut-off switch?"|
no; remember all 1275 Spridgets had elec pumps and did not need regulators or cutoff switches.
|>>> And this means cranking the whole heavy engine for quite a bit just to operate the fuel pump. <<<|
Yes, but this also pumps oil through the engine before it fires. Silver lining...
My 1500 generally fires up pretty quickly after sitting. I wonder if your pump is faulty, because they're dead simple in theory. You may want to check and see if the little check valves in the upper part of the pump body are working okay. I had one of those fall out once, at which time it ceased to work...
Something else that might help is to blow air back through the fuel line to clear any possible blockage. I used a can of air like you'd use to blow dust bunnies out of a computer - I had the tank off at the time for cleaning, and when I stuck the little tube into the fuel line up front, sealed it with my thumb, and pressed the valve, fuel shot out a good six feet behind the car. So that's a nice easy way to backflush a fuel line, although a compressor (which I didn't have at the time) would do just as well or better.
Do you have a fuel filter anywhere in the system?
|glad to hear that i am not the only one sold a pup by cheap repro piece of rubbish,i thought i was doing a good thing by putting a new fuel pump in to my 1500 but every 300 miles the thing would fail as the acruator arm would bend until it copletly missed the cam.|
there should be a law against it
Have you checked the pump diaphragm isn't punctured or the brass gauze filter blocked?
Incidentally the gauze filters are no longer available on their own - you have to buy a complete pump (of doubtful quality apparently)
I lost the gauze filter from my pump, but have an in-line filter anyway.
|Douglas, you wrote:|
>>> ...but every 300 miles the thing would fail as the actuator arm would bend until it completely missed the cam. <<<
Apologies if I'm stating the obvious, but the 1500 was fitted with two different fuel pumps during its production run. In the earlier engines, the pump was fitted directly to the engine block, while later ones had a heat-insulating spacer between the block and pump to help prevent fuel vaporization. This latter arrangement stood the pump away from the block a bit, and necessitated a longer actuator arm.
I've only replaced my pump once, and that was years ago. So I don't know what would happen if you tried to fit a later pump without the spacer; that is, how the longer arm would work with the pump bolted directly to the block sans spacer. Does your pump use the spacer?
This thread was discussed between 06/08/2010 and 10/08/2010
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.