Relearning to drive a carby based car.

tlampre

tlampre

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Fellow Frogger
Joined
Sep 9, 2005
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167
Location
Melbourne
It's been over 10 years since I owned a car with a carby and I'm having trouble remembering what's normal behaviour.

When I start the BX after it's been sitting overnight it will fire up instantly with no choke or pumping of the pedal. But after a few seconds it will die regardless of what I do with the choke or pedal. I then need to crank it over for about 5-10 seconds before it will start and continue to idle. I need a bit of choke at that point.

I'm thinking the first start is happening off of what is left in the float chamber but the fuel line has drained overnight and the float chamber empties out before the fuel pump can draw more in to fill it.

With my other carby cars I can remember pumping the pedal once or twice before turning the key if I wanted them to start immediately but this just seems to flood the BX.

Any ideas?

Regards,
Trevor
 
I think your right. It's running on the fuel in the fuel bowl, but not sucking fresh juice up from the tank in time. You could replace the one way valve in the fuel pump .... Or simply mount the fuel filter just before the carby higher than the carby slightly (this way the fuel from the filter back drains to the tank, but the fuel between the carby and filter doesn't drain off :D ).

seeya,
Shane L.
 
Huh, choke?

Shouldn't it have an auto choke? Both my parents and sister's carby BXes have an auto-choke, so did the early GT that my sister's boyfriend had. On all of them you were meant to depress the throttle pedal to the floor before starting, to set the choke...

Surely the fuel pump could refill the float chamber PDQ.

:2cents:

Chris
 
chris said:
Huh, choke?

Shouldn't it have an auto choke? Both my parents and sister's carby BXes have an auto-choke, so did the early GT that my sister's boyfriend had. On all of them you were meant to depress the throttle pedal to the floor before starting, to set the choke...

Surely the fuel pump could refill the float chamber PDQ.

:2cents:
Chris
Click to expand...
Mine is a manual choke alright, a common retrofit when an auto-choke dies as it's often cheaper. The stock RE had a manual choke though, according to my manual, which had me going at first trying to identify the carby. My 16TRS seems to have a few mongrel bits on it.

I would expect a fuel pump to fill the chamber PDQ too, so I think it may be on the way out.
 
Pull choke all the way out.:dead:
Pump throttle three times.:mallet: :mallet: :mallet:
Push choke back 1/3.:approve:
2 inches of pedal.:headbang:
Turn key to start.:cussing:
Depress right foot to desired revs.:chase:

Always worked on the one tonner.:snail:
 
Had similar issues with my GS sedan. Turned out petrol was weeping through the fuel pump diaphram. Swapped over the fuel pump and now it starts first pop even after sitting a few days.:D
 
Gamma said:
Pull choke all the way out.:dead:
Pump throttle three times.:mallet: :mallet: :mallet:
Push choke back 1/3.:approve:
2 inches of pedal.:headbang:
Turn key to start.:cussing:
Depress right foot to desired revs.:chase:

Always worked on the one tonner.:snail:
Click to expand...
By golly, by jingo, by gum - I think he's got it!:bounce::bounce::bounce: :thanks:

Gotta back off on the choke pretty quick though as it won't idle unless the choke is only just engaged and I need to turn it off completely while moving otherwise it runs rough as guts even when stone cold. Then back on a bit at the lights round the corner... then off and hopefully it's warmed up enough by then to not have to bother with. Can't wait until winter! :rolleyes: Spoiled by EFI!

:drivin::drivin::drivin::drivin::drivin:
 
I find that if mine has only been sitting overnight, all I need is full choke and it starts as soon as the starter turns. If not, it normally starts within 4-5 turns. After car has risen to full height. it's usually OK to push the choke in a little bit.

As far as I can make out, it's a factory fitted manual choke.
 
While looking for my LHM leak I happened to notice the tag on my carby. It's a 34 DRTM Weber. All the specs I've seen says 32/34 DRTC. Maybe we got a different carby here in Australia to comply with local regs and it came with a manual choke?
 
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