TR2/3/3A Starts Cold, Not Hot

New car to me. Car starts right up cold with a little choke. Take it out for a short ride and turn it off, it will restart right up. If I let it sit for five minutes or more it won't start. I've done a plug check and they are dark so I've been screwing in the jet head adjuster. Cleaned the plugs and reinstalled them. It still won't start. Any ideas?

Sometime the bowls let in too much fuel in and a car will start cold and be too rich hot and flood. I think you are looking in the correct area, but always remember most times the problem with SU carbs is usually the Lucas distributor. I would check the bowl needles and arms plus sometimes those round ball jets cause the problem you mentioned.
steve

sp53 said:

but always remember most times the problem with SU carbs is usually the Lucas distributor.
steve

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What is the problem with the distributer? And where are the "round ball jets"?

There is nothing wrong with the distributor and the ignition system works great when in good condition and set correct. What happens is the points or plugs or plug wires wear out and people start playing with the carburetors to fix the ruff running motor, but the point gap is off or something else is actually off making the problem which when that is off that changes the ignition timing, or the plug wires are old and shot creating resistance in the wirers and the firing of the spark plug. Weak spark is a big problem with tuning these cars. Get metal wires and make good clean connections. The gig is to get all the ignition stuff done first then set the valves cold at. 010 and then see how the car runs with choke in and warmed up.

The choke system on a tr3 can be a real bummer and let the fuel jets stay open and flood in more gas and make your symptoms also. Look at the jet and make sure it has fully returned after the choke is in and the motor is warm say ½ hour of running. These chokes kinda work backwards of other old cars in that they let more gas in and not shut off the air to choke the motor.

The ball would be an aftermarket needle float assembly that people put in for higher performance with the fuel. You would need to lift the lids off the carburetor float bowls and look to see what you have.

It is always best to do a full tune up to know where you are at: plugs, points, condenser, and new distributor cap, plug wires the whole system then do the carbs last.

steve

frankfast said:

New car to me. Car starts right up cold with a little choke. Take it out for a short ride and turn it off, it will restart right up. If I let it sit for five minutes or more it won't start. I've done a plug check and they are dark so I've been screwing in the jet head adjuster. Cleaned the plugs and reinstalled them. It still won't start. Any ideas?

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I think the first thing I would recommend is pull the domes and pistons so you can visibly see that the float valve assembly,whatever type you have, is holding and set at the correct level,visible as fuel level slightly below the jet top.
Fuel at the top of the jet would be a leaking valve,or to high setting.
Open up the float chamebers if the level needs adjusting.
Good time for cleaning and a drop test to check jet centering etc,then adjust as necessary.
Tom

I centered the jets to no avail and then the last time I drove it, I noticed gas coming from the overflow (breather) at the top of the float chamber. When I pulled the lid off the float bowl, the gas was at the top of the chamber. The float goes up and down okay and the needle valve is not stuck. I suspect the needle valve or seat is worn so they are on order. I hope this solves the starting problem when hot. It makes sense that the front carb is flooding.

What kind of fuel pump? People put electric fuel pumps on these cars that produce 20 psi and the stock fuel pump is 2 to 1 ½ psi; so what happens is fuel is forced by the jets and out the top of float bowl. plus that would make for a rich cold start mixture
steve

It's not electric. Looks to be the original or replacement. I can only see that it was made in Canada.

Needle and seat replacement is good idea.
Also check that the jet sizes are identical on each carb.

yes Malbaby plan could make a big difference and al lot of these cars have that Canadian fuel pump and it will be fine

Take the carb floats out and shake them. Make sure there's no gas inside the floats. The original style metal floats are prone to cracking and filling up with gas. Then they sink and keep the valve open forever.

The float goes up and down as it should. Gas was at the top of the bowl on the front carb and about three quarters full on the back carb. Both floats seem to work fine.

Seems like the problem is solved. Upgraded float valves from Moss did the trick. It even idles at a respectable level. Thanks for all the help. On to other issues.