MG Midget Forum

I recently dragged home a rescue Midget that was left lonely and abandoned, finished assembly of the most complete engine out of 3 that came with it and got it running the other day, not very well but running none the less. My question is, I put on a new mechanical fuel pump from Vic British but I'm not sure it's pumping enough fuel once I run the rpm's up. Starts and idles good but stumbles badly beyond about 1500rpm. Put in a clear filter and don't notice much of an increase in flow with rpm increase. Should I? If I were to add an electric pump could I put it inline before the mechanical and just flow through or would I need to remove and block the mechanical one? Or should I try another mechanical from Vic British? Thanks, Rob

Rob,

Make sure the carb float level is correct.

Remove the fuel line and direct it into a gas can and then have someone turn the engine over. If fuel squirts out you probably have enough pressure. If this is the case I would look elsewhere for your problem. It could be several different things. I could be the float level in the carb as Rick suggests or it could be the advance timing mechanism in the distributor is rusted and hanging up.

---

Jere McSparran
JMAC Engine Shop
Website: http://www.jmacengineshop.com
email: jmacengineshop@gmail.com
Phone: 217-232-7303

X2 Jere

I agree you need to find out what's causing the issue before adding an additional fuel pump. But answer your question of where you can add an electric fuel pump, I have an electric pump installed in the trunk on my 78. The mechanical pump is still mounted to the engine and operational.

Small low price electric pump is all that is needed. 2-4 psi max, no regulator needed. Block off the mechanical drive opening.

---

Iceman

Atlanta GA

71 MG Midget

62 AH MKII
67 Midget
71 Midget

Just check that the fuel lines are not rotten on the insides as they will restrict the flow as happened to me and it took two new fuel pumps and several hours of grief to figure it out

Thanks for all the good input. I put all new fuel lines in, check that one off, will try the pumping gas into bottle. How do I check vacum advance movement and carb float level (Weber Downdraft)? Thanks again, Rob

Your problem may well be the Weber. Car wasn't designed for it or it for the car and others have had trouble.

Kurt

If it was a side draft Weber, I would congratulate you, but those downdraft Webers have a very bad reputation, though there are members here who have dialed them in. Stock SU's carbs or Weber side drafts are very expensive. A good set of used stock carbs may be your best bet if that turns out to be the problem. You could run a "Lawnmower" gas tank up high, over the engine, put a shut of valve on it, and that should give you enough pressure to start the car.

The Weber was designed for that car, just poorly designed. You have to take the carb apart to adjust the carb float. I would highly suggest you do that, as that could solve all your problems., especially if you are going to keep that carb. Get a carb rebuild kit/ with proper gaskets, and lots of carb cleaner. Make sure the float actually floats, and down't stick, which would starve the car, and change the needle valve, and seat, all the stuff you do when you rebuild a carburetor. It's not hard, you just have to be patient, make sure fluid shoots through all the holes, and change out what you can, like the needle and seat, and mostly, keep track of what you are doing, and have no parts left over. There's probably a book on that carb somewhere. I'd look for a "Free" .pdf download.

There is indeed a book on the downdraft Weber, it is a proprietary manual that goes with the sale of Pierce manifolds. There is also a book on Amazon from a former Weber tech and published in France of all places. Find a download and print off the pdf if you can. I reprinted the Pierce instructions, followed it to the letter on my teal blue Lizzy years ago. I think I had it dialed in about the best I could, but there were times where I just didn't feel like it was giving me the performance I wanted.



Edited 1 time(s). Last edit at 2017-10-20 01:08 PM by littlecars.