CARB......FUEL PUMP?

[Cyndi Kritzinger]

I'M EXPERIENCING A BIT OF A PROBLEM WITH MY BUS CUTTING OUT EACH TIME I SLOW DOWN AT A ROBOT/STOP STREET OR WHEN I WANT TO TURN AT AN INTERSECTION.
IT RUNS SWEETLY OTHERWISE.

IT'S A STD SOLEX TWINCARB 2L AIRCOOLED BUT WITH AN ELECTRIC ROTARY FUEL PUMP (DUE TO THE MECHANICAL PUMP CALLING IT A DAY).

SUGGESTIONS????

[retrovan]

It could be the pressure to high or the float level in the carb being too high.

If my memory is right it should be between 12 and 14 mm from the top edge when you carefully remove the top of the carb.

Herman

[Cyndi Kritzinger]

PRESSURE FROM THE ELECTRIC PUMP TOO HIGH, YES. WE KNOW THIS.
I HAVE ADJUSTED THE NEEDLE AND SEAT BY FITTING A SLIGHTLY THICKER WASHER.

NON OF THE OTHER WISE MEN GOING TO MAKE SOME SUGGESTIONS?

[Tony Z]

you know the problem... what more should we add?
Adjusting the needle and seat isnt going to help, its not designed for the pressure you are introducing to the carb
get a 3psi pump and you'll be ok

[Cyndi Kritzinger]

HOWDY TONY.

I HAVE TRIED A NUMBER OF PUMPS NOW.
I WAS TOLD THAT THIS PUMP WOULD DO THE TRICK.
WHICH PUMP SHOULD I GET AND WHERE?

[calooker]

Crap in the idle jets

[Donovan D]

Try and get a pressure gauge and check the fuel pressure.
I think there is a thread somewhere about a Facet fuel pump - 3psi max, that Herman posted about.
Maybe get a pressure regulator ?

[acpaterson]

Pressure regulators introduce another area where a leak can occur. Saw this first-hand.
Get a lower pressure fuel pump Mark. only way to go here.

[retrovan]

Try and get a pressure gauge and check the fuel pressure.
I think there is a thread somewhere about a Facet fuel pump - 3psi max, that Herman posted about.
Maybe get a pressure regulator ?

Facet fuel pump - 3psi max from Midas if you have Solex carb, or Huco 2psi max if you have Weber.

Make sure it is 3psi max as there are a number of Facet pumps all with higher pressure that look the same.

Just mount it on rubber or it will drive you mad.

Herman

[Riaan.N]

If I can throw a question in... how is the quality of those facet pumps and are there better pumps?

From your comments Herman, it seems like the facet pumps are very noisy.

[sean]

There are many other factors it could also be, and not even carb related.

I had a bus that I spent days struggling with twin carbs only to find out it had a slight vacuum leak on the pipe running to the brake booster. It was small enough to not have a noticeable effect when driving, but kept throwing the idle out.

The carbs themselves may not be set up correctly. The 2L twin carbs can be a real bastard to set up idling correctly.

Is it flooding when it dies? Does it have black smoke when you restart it? I have had good success with Facet fuel pumps and twin carbs, although removed later to fit original, there was no noticeable difference.

[sean]

If I can throw a question in... how is the quality of those facet pumps and are there better pumps?

From your comments Herman, it seems like the facet pumps are very noisy.

Extremely reliable and made in the USA. Very good quality, they must just be mounted on rubber mounts to not transfer noise into the cab.

[Riaan.N]

Thanks Sean

[retrovan]

..........From your comments Herman, it seems like the facet pumps are very noisy.

Its an excellent pump, but it is a pulse pump, and not a rotary pump.

So it tends to be noisy with a pronounced tak -tak-tak sound, and if mounted to metal, it has an amplifying effect

So when rubber mounted, it has a nice soft sound which increases when you run out of petrol.

I normally fit a fuel shut off solenoid as well so you can not have gravity feed when off.

Hope this helps

Herman

[Tony Z]

I've decided to look at the facet catalog...
those cube pumps of theirs seem to no longer have the low pressure version that we've always used in the past. Part # 40104 is their lowest pressure cube pump and is rated at 4psi which is too high for our carbs
they do have a 2psi pump which is part # 60304 but its unlikely that you'll find this one locally