stag not starting when cold

[speedy]

stag will not start when cold. can be started when holding hand over carburettor intake
starts and runs fine when hot. choke discs are in correct position, float pipes adjusted
correctly, suggestions please

[martin]

stag will not start when cold. can be started when holding hand over carburettor intake
starts and runs fine when hot. choke discs are in correct position, float pipes adjusted
correctly, suggestions please

Float pipes ?

[speedy]

sorry, should have read float heights

[martin]

Gotcha, sounds as if it's very lean, providing your ignition is OK. Martin.

[staginhiding]

How does it run when its warm? it does sound like its running weak or the chokes not working for some reason..

[speedy]

[QUOTE=staginhiding;221172]How does it run when its warm? it does sound like its running weak or the chokes

When it is warm engine runs well. C/o is 2.5%. H/c is 400.
Ignition timing 12%.

When starting from cold no attempt at firing

[V Mad]

If the enrichment levers are being operated correctly, then because covering the intakes effects starting, there is a possibility the enrichment mechanism is not working, maybe the holes are blocked (Alan will no doubt comment on the unlikelihood of that)?

[speedy]

I am thinking about putting the float heights a little higher [now set at 17mm] has any
one had any experience of that?

[V Mad]

That will probably put your CO up over the limit and waste fuel.

[speedy]

The choke mechanism has been dismantled and thoroughly cleaned and reassembled
with the large cut out on the disc close to the fuel supply hole. A mini vac pump was put
in the carb body choke outlet hole (i.e. piston removed)
With chokes off no fuel was drawn through. Chokes on; fuel was drawn through so
assume that is now assembled and working correct.
When engine is running if chokes are pulled out it enrichens the mixture enough to
make the engine start chugging.

[V Mad]

Is your coil 12volt starter boost working?

[speedy]

Is your coil 12volt starter boost working?

I have just checked voltages on car and coil hoping V Mad had found something i had overlooked
but unfortunately ignition on coil is 8v cranking 9v so it would appear OK

My current thinking is heavy build up of coke on inlet valves absorbing fuel or valves not seating correctly
I have access on Monday to a Snap on cylinder efficiency tester [puts a measured amount of air in cylinder at T.D.C and measure the amount of air loss] and see what the results are. Has anyone ever tried this?

[V Mad]

I have just checked voltages on car and coil hoping V Mad had found something i had overlooked but unfortunately ignition on coil is 8v cranking 9v so it would appear OK

Your coil voltage on cranking should be boosted up to full battery voltage to aid starting. 8 volts is not going to give you the best spark.

[cliff wilkins]

I feel for you I am having exactly the same probelm and am now out of ideas and patience its even been to a specialist.
after biting the bullet even after spending a good few pounds changing a lot of items no start cold.

Stumped completly now with no options just wont start from cold but when and if you can get it going starts on the button warm.
Really really dont know where to go with it at all.
Hope you have better luck than i have had.
items done to date.
Plugs
Leads
Choke cable both chokes working spot on
carbs tuned & checked few new o rings fitted, checked c/o 3.50 timing is spot on
various pipes done vacuum pipe elbows
diaphrams
earth lead cleaned checked
rotor arm /cap
mk2 so no ballast resistor
If anybody can help would be fantastic No mechanic myself thats why it went to a specialist still no cold start
All the best.
Cliff.

[wilf]

Speedy - you are describing a leak down test which basically checks the valve seating.
Have you done a compression check yet?