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MG Midget and Sprite Technical - 1500 Wont' start despite new fuel pump?

Hi,

I broke down over the weekend and the AA Patrolman confirmed that it was the fuel pump.

Subsequently I have fitted a new pump but unfortunately whilst the Midge appears to have power there is no ignition still ?

I have tonight removed the two hoses attached to the pump and then turned over to see if there's any fuel being delviered to the pump but there is no fuel coming out of the hoses?

Does anybody have any recommendations of what the issue could be and how I can either prime or get fuel to the pump?

Thanks.
L Huggins

A better test is to disconnect the hose that goes to the carburettor(s), place the end in a jar, and crank the engine over.

Did you fit your 1500 with an original-spec mechanical pump? Did you get the hoses fitted the right way around? Sorry to state the obvious, but I know I've made similar mistakes in all the excitement...

I'm sure you checked to make sure you had adequate fuel in the tank. Could the pickup be blocked with something?

The midget fuel system is quite simple, so we should be able to come up with a cause pretty easily.

Cheers,

-:G:-
Gryf Ketcherside

If you need to prime the pump just suck on the outlet hose from the pump (once you are sure of which is which!) until the fuel reaches the pump.
Avoid a mouthful of fuel, of course.
JB Anderson

Do you have the correct mechanical fuel pump fitted? There is an early and late mechanical pump for the 1500. The L shaped pump arm is shorted on the earlier pump and won't reach the cam on later engines because of teh heat spacer on the block. It will still work if you remove the pump spacer and you might need shorter studs too. Make sure the curved arm isn't under the cam when you install it.

I haven't had this problem but if you put gravity feed fuel jar on the carb, the engine will start and the fuel will come out of the pump eventually. As has been said before, make sure the hoses are on the correct way. Easily done because I've done it too!
Clive Reddin

Thanks for all your comments. Little daunting this when your new to the mechnical world!

The tank is full !

I had thought that I had the hoses fitted in the correct manner and the new pump is an exact replacement for the old verison.

The supplier actually sent both versions so that I could match up the correct one.

If I am to pull/suck on the outlet is this (when looking birds eye view directly on top of pump) the hose to the right or, to the lower left?

I will certaily try the carb end line/hose theory also.

I'm sure all will get sorted...............eventually.
L Huggins

If your fuel pump is like mine, there should be flow arrows cast into the cover.

Best of luck... keep us posted,

-:G:-
Gryf Ketcherside

One fuel pipe runs from the rear of the car, comes up by the gearbox tunnel and onto the pump.That is the inlet pipe so leave it alone.
The other pipe leaves the pump and runs behind the engine below the heater to reach the carbs.
That is the pipe you want to apply suction to..you can disconnect it from the rear carb to suck on it, rather than from the actual pump if it is easier.
JB Anderson

Hiya,


Got an idea there 2 types of pumps on a 1500, make sure the arm is the same length as the one you took off. The spacer and studs are different lengths, maybe the arm on the new one isn't touching the lobe on the cam?

Just a thought.

SR Smith 1

"Subsequently I have fitted a new pump but unfortunately whilst the Midge appears to have power there is no ignition still ?"

Could you clarify your above statement - power ?, no ignition still!!!?, - what made you replace the fuel pump?

What do you mean by no ignition and why would replacing the fuel pump solve this?
S G Macfarlane

If you do have the correct pump and it isn't drawing fuel, there could be an air-leak somewhere on the pipe between the tank and the pump.
Dave O'Neill 2

I fitted a pair of clear filters to my 1500 - one just before the pump, and the other at the carb. It's a good way to see if you have fuel at those two locations, to say nothing of the filtering.

-:G:-
Gryf Ketcherside

I just thought of something often overlooked!

If you follow your metal fuel line, it goes down over the transmission to below the car. There's a rubber hose, more like vinyl actually, that connects to the fuel line running under the body. (It wasn't flexible any more and broke when flexed.) I had one break one day and it gave the same situation as a broken fuel pump diaphragm.

I found that because I replaced the fuel pump and nothing came out. Reversed the lines and same thing. Followed the line back and there we go! Broken rubber hose. Replaced it and were up and running in no time!

Maybe that's your problem? Something to check out just in case.
Clive Reddin

Hi All,

Well, I followed your advice and I would believe that I probably had the hoses on the wrong way round so switched them.

If I have this right, the inlet is attached to the 'arrow' mark on the fuel pump and therefore the outlet is on the other. The outlet leads to the carb(s)'.

I have (hopefully) uploaded a photo and I'd be grateful if you could take a look and confirm.

I have turned over again (with inlet removed) and there was fuel coming out so I'm hoping this has worked.

I say this as I was unable to start up as the battery is now flat!

Will buy a charger and run another test tomorrow evening.

Cheers.



L Huggins

Oh, sorry, one other thing.

In the 'excitement' of taking out the spark plugs to save the battery (it was too late anyway!) I removed the HT leads.

Once replacing the plugs I then became confused as to the order in which the leads are supposed to be attached.

Again I've uploaded another photo - are these correct?

Thanks.

L Huggins

1342 - sorry on mobile so photo isn't big enough for me to see, but that's the firing order - hope that helps
rachmacb

Looks Ok to me, as far as I can tell.

Before I changed to an electronic distributor the vacuum advance diaphragm thingy on my 1500s distributor was pointing more towards the fuel pump than yours. I know there are reasons that could account for this without it being a problem, but is your timing set up correctly?

JB Anderson

As it was running OK before (apart from the pump) you'll know when it's running if you've got them out of order

I've made that mistake more than once, when you know they are correct mark them up

you're now fully aware of the usefullnes of a good well charged battery

as you're charging up the battery (not whilst plugged in of course and wear protective gear across eyes, body and hands)

check the water levels in the cells, top up with distilled if required

clean the battery lugs

check and clean the battery connectors

check and clean and secure as required the connected end of the earth lead (and earth wire under car if you can)

check live lead is secure to starter solennoid and protected

when you reconnect the battery make sure it is restained well and has secure and proteced connections
Nigel Atkins

Great news.

Having follow the advice (thanks!) I turned over tonight (once battery was charged) and it fired on the 5th attempt and ticks over superbly.

THe only problem I have now is how I close the passenger door as I couldn't open it internally and decided to remove the latch but now that's frozen and I can't shut the door?

Cheers.
L Huggins

probably just the lug not lining up with the hole from the inside handle

three screews, two very small at top of inset triangle and third holding handle

lift off handle then inset and you see how it all lines up
Nigel Atkins

This thread was discussed between 05/05/2011 and 12/05/2011

MG Midget and Sprite Technical index

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