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MG MGB Technical - Moss/Cobalt EFI

I run A/C in a hot, desert climate so in the dead of summer, I have trouble with carburetors vapor locking. The original HS4s get too hot and run/start poorly in the heat. Gasoline laced with alcohol makes this worse. I tried Mikunis and these were terrible with high under hood heat (great otherwise). I am currently running a downdraft Weber and it has proven to be more heat tolerant, albeit with terrible cold starting characteristics in the winter.

Moss is now offering throttle body fuel injection (for a price). Due to high fuel pressure, this system should be very heat tolerant. If anyone has tried it and can present a review, I am curious how well it works out. It looks like a good solution in most respects, especially if an O2 sensor is in the loop.

Hold on to your wallet!
Glenn Mallory

Maybe supplying some cooler air, (i.e it hasn't risen from the manifold, or already been heated by passing through the radiator), by ducting from in front of the rad, might be A LOT cheaper!!!
Ceramic coating the manifold would, no doubt, help too.
Allan Reeling

Glenn, When we moved from the Adirondacks, New York to Tampa Bay, Florida I had the same hot weather issues with my 79. I run a DGV Weber (electric choke) with no issues cold starting. 185-F thermostat and 10W-40 Castrol.

Moved to Florida, car not happy with the heat.
Installed a heat shield under the carburetor, 165-F thermostat, and 20W-50 Castrol.

To increase air flow, I removed the rubber gasketing which resides on the top lip of the firewall so the hot air can escape. This helped immensely to alleviate heat.

Hope this can help you

Cheers

Gary
79 MGB



gary hansen

Glen
There is a fella on the MGA forum occasionally that runs fuel injection on his A--I'm not sure if its a single tb or seperate injectors -He's had issues with the timing of injector pulses so I would guess seperate but has sorted it now .He lives in Queensland so plenty of heat and will know of any issues
Probably best if I get him to email you if you want----------
William Revit

To save all the problems with port robbing with fuel injection timing you might be better off going for a single d/d weber manifold and a single throttle body like--

https://www.advancedautomotives.co.uk/weber-downdraught-retroject-3838-fuel-injection-throttle-body-kit---webcon-atb400-6604-p.asp

Some of the 6 cly Fords here run a similar body and really there's not much difference in performance between them and the multi injector equipped same cars
Maybe some ford over there might have similar and you could find one at the wreckers, they're just about a giveaway item at the wreckers here

They run a lower fuel pressure and you could run it with something like an Omex ecu

Just a thought
William Revit

Ford throttle body

William Revit

I found that the choke was disabled on the Weber, probably the cotter was missed at the factory. Once properly assembled, the car starts--and runs--beautifully. No need to complicate things with EFI.
Glenn Mallory

This thread was discussed between 17/02/2020 and 14/03/2020

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