Message text written by "John Macartney"
>>Sorry but I got the kind of carb wrong. It's a single Zenith Stromberg.
On a
>76 Spitfire (California).I checked the jet for dirt and it's fine.
>I did notice that my catalytic convertor this last time got red hot—it
>glowed! Also the middle part of the exhaust manifold.
>Could my catalytic be partially blocked and causing the hard starting when
>the engine is hot?
>Thanks again.
>Dave Koszka
<
Dave,
Your car is running too rich when your converter glows like that. Excess
petrol is running in the intake and incomplete combustion is taking place
in the cylinder and the catalytic converter is finishing the job but the
excess heat is showing. There are a couple of possible reasons are that
the float chamber is overflowing or the start-up circuit is not closing
down once the car warms up.
First, make sure all the spark plugs are working and the timing is right.
Before you start on carb problems make sure the ignition system is correct.
Check the cap, rotor, wires and plugs. If all is OK proceed to the next
step.
Does the engine idle down properly when warm? If it races then I would
start looking at the start-up circuit. It is the big round thing on the
side of the carburettor with coolant hoses attached. First check to see if
the metal part gets warm. If it doesn't then you may have a blockage which
must be resolved. Other sources of problems is corrosion in the unit if
the car has sat idle for a long time. You might want to have the
carburettor overhauled.
If the problem is the float chamber overflowing then the engine will idle
down. In fact, it might try to die on you form too much gas. Check the
float and the needle and seat the the float actuates. It could be a bad
adjustment, a sinking float (where the float leaks and fills with gas) or
dirt in the needle and seat preventing closure. An overhaul may be the
needed thing again.
Check these things and write back. Good Luck.
Dave Massey
57 TR3
71 TR6
80 TR8
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