AC fuel pump diaphragms

[andrew honychurch]

I am just refurbishing my AC fuel pump and even though its new, the diaphragm is not going to work for very long from past experiences of these items. Modern fuels with ethanol tends to dissolve the old material. I wonder if anyone has dealt with this problem other than by putting in an electric fuel pump. Is there anyone out there making new diaphragms? Given the tendency for Carriers to suffer with fuel vaporisation maybe an electric pump will be the best way forward. Any thoughts much appreciated.

[rob love]

Dealers of the antique parts have adjusted their new stock for the ethanol blends. Here, for instance, is a link to MAC auto's fuel pump, which states: "This pump is compatible with current E10 ETHANOL fuel blends".

http://macsautoparts.com/early-ford-...R3CHL1073533E/

Many of the dealers have adjusted their rebuild kits as well towards the new fuel blends.

[andrew honychurch]

Thanks Rob. Unfortunately this is not the fuel pump fitted to the T16 ( I mitted to mention my vehicle in the post) . I will check with one of the "new" V8 suppliers and ask whether they do a diaphragm for a T16 pump, it woudl certianly be the best way forward. I just wondered what everyone else does. Maybe there arent that many running Carriers on the forum!

It has certainly been my experience that old material will turn to goo pretty quickly once petrol hits it, and of course this coudl endanger the engine if the fuel drains down into the sump diluting the oil. So you have a double worry with old diaphragms ( nothing changes in life does it?)

[horsa]

Brian Asbury has rebuild kit rubber diaphrams for the T-16 fuel pump. I got one from him a few years ago when I was rebuilding the one for my carrier. It seemed to work OK with modern fuel but only time will tell as it sits exposed to the ethanol mixture.

Because of fuel/pressure issues I ended up hiding a remote modern electric fuel pump to ensure 3.5psi of fuel. It also prevents flooding when things are hot and you shut down the engine which would then have made it impossible to restart without sitting an hour. I'm still pushing fuel through the orignial fuel pump but am not using the lift rod on the engine which would pump the diaphram.

[andrew honychurch]

Interesting information thx David. I did much the same on my Stuart tank and replaced the original diaphragms with a simple neoprene gasket and then fitted an electric fuel pump instead. I am minded to go with the latter as another problem with modern fuels is the ammount of additives which seem to turn into gases and cause vapour locks. I have found on other vehicle having a modern higher pressure pump will help compress the gasses and allow fuel through when hot. I think a lot of modern systems get by this problem with having returns to the fuel tank from the carburettor. I did read your old post and you stated that there was a difference between the Carburettor pressure requirement and the fuel pump output. I can certainly see from the manual what the AC pump puts out from the manual but i have not found out any information on what the Holley carburettor is designed to accept. I am sure in the long run, the T16 will run better with a modern fuel pumping system in place.

EDIT...the point being that if one has too much pressure then presumably the carb will flood

[horsa]

A fuel return would have solved a lot of problems and ensured easy starting. But I couldn't think of a good way to hide it so settled for the electric fuel pump on its own.

On the pressure, seems like the original fuel pump is either 4 or 4.5 psi and the carb was 3.5 psi. Not a problem if everything was seating properly and the fuel pump wasn't actually putting out more pressure than it should. I never determined where my problem was coming from. Had lack of power trying to accelerate under a load when hot and it seemed to be flooding itself. The electric pump with pressure regulator solved everything which made up for my inability to resolve the mechanical problem properly.

[andrew honychurch]

That seems a strange conundrum in many ways. Lack of power under load would have suggested to me, if it definitely fuel related, that it was short of fuel but yet it was flooding. I would have thought problems therefore within the carburettor, but as you say an electric pump solved it it must have been fuel starvation. Perhaps as you were flooring it to kepp it going it was pumping what fuel it did have in the bowl through the accelerator pump and that was causing the flooding. Its a strange one, but as I said before, and from your experience, Carriers, well T16's anyway, are well known to suffer when hot. There is a guy I know who did his National Service on them, and said they were for ever stopping and couldnt be restarted. That said ( sorry to all you othe Carrier owners) when the T16 was working it was far the best of the bunch due to its power and better steering. But I digress and will no doubt be mown down for his views

[Lynn Eades]

I know nothing about the T16, but withe flathead ford v8, I believe the fuel pressure is supposed to be 2 1/2 psi. This is solely dictated by the spring in the pump. With higher pressures problems like flooding occur.
Volumne is another issue.
Even us mechanics easily confuse flooding and starvation.

[Marc van Aalderen]

Originally Posted by andrew honychurch

I am sure in the long run, the T16 will run better with a modern fuel pumping system in place.

Andrew,

Dirk Leegwater has NOS 6v fuel pumps. If you want I'll pick one up for you as you need the drive gear also. I'm going to Dirk in the next couple of weeks. Just let me know.

Cheers,
Marc

[andrew honychurch]

Thanks Marc, but as its a 12volt system I intend on putting a modern fuel pump in line. Been stripping the instrument panel this weekend, and need some items for that. I have all the guages, but I am in need of the small pop out red cut out, a siren switch, starter switch and a socket for the auxillary light lead. They all look like standard US style parts but carry a G166 part number and I am sure they are all different to the Universal carrier. Quite depressing trying to find all the stuff I need!

[Marc van Aalderen]

Your welcome. I did not know these were 12 volts. You learn something new every day on this great forum.

You still need the drive gear? Just making sure.

Cheers,

[andrew honychurch]

yes please, that would be great. thx