Model B Non start

T

tiger.1000

Well-known member
No amount of cranking will get my 32 Model B to start. However remove the spark plugs and give each cylinder a spoonful of petrol, engine will start and run for a few seconds then stop.

Removing fuel inlet pipe from carburetor then cranking engine gives fuel.

Zenith carburetor was rebuilt by Dave Renner about 2 years ago and until today performed faultlessly.

Any clues?
 
Starts with fuel dumped in...so...

Remove plug at bottom of car...does fuel come out, maybe about half a cup?
If carb seems to be full...will engine try to start with full choking??
If not...spray carburetor cleaner or other nasty flammables into carb throat while engine cranks...it should try to start.
It sounds like either carb is not actually getting fuel...clogged inlet, bad float valve, fuel pump is feebler than it seems...or
carb has fuel but something, most likely dirt, is preventing its delivery.
 
Model B has a fuel pump . Perhaps it is not working or the line is plugged or the inlet line from the tank has a vacume leak and will not draw fuel from the tank???
 
I would guess you have blockage between the Carb float and the main throttle body... not sure of the proper names. basically clogged jets.
 
OK...if nothing comes out, probably:
Fuel pump is weak even though you see some output
inlet valve is plugged or stuck
fuel line is plugged...less likely

I would first try gravity feed as a diagnostic: Point fuel line, still connected to carb but off the pump, up...put a rubber hose over it, hook that to a container with a small amount of fuel in it. See if car starts, if not pull plug to verify that carb is still empty.
If carb cannot fill this way...take it off and remove the single bolt holding top and bottom together. Scrutinize inlet and float assembly...something has closed the door!
 
"There is fuel entering the carburetor inlet....see original thread. ????"
You say pump is pumping...but removing bottom plug shows no gas...if that is correct, fuel is reaching the inlet but not going through.
 
if you consider the engineering of the carb. The gas comes into the float side where it then is fed into the throttle body and mixes with air, enters the manifold then cylinder and ignites. If you choke the heck out of it and do not get any sputter and do not get gas leaking out the carb, the gas is not getting from the float to the carb center section. likely a piece of crud in the gas is blocking a passage or jet.
 
Fuel is newish and there's no rodents in the exhaust pipe ! I'll try gravity feed then report back. General concensus of opinion is sticking float valve...

I'll report back in a day or two
 
Thanks to everyone for advice. A gentle tap on top of the float chamber cured the problem. Diagnosis.......stuck float needle valve!

The old jalopy took on a DB9 at the lights.......
 
You must log in or register to reply here.
Back
Top