Hard cold start

[wit61]

The cold start problem that I had some time ago has returned, or more likely never went away. Here it is :

When cold, the motor turns over, but will not fire. I have traced this to a fuel delivery issue. I can actually see that fuel is not flowing through the $2 filter I put inline. I can always get the car to start by popping the air cleaner and "priming" the carbs with fuel. This works regardless of how cold it is. The car then runs normally from that point on (ie: fast idle then slow). The problem goes away once the car is up to temp, and it will sart happily all day.

I have been assuming that the carbs (TVMs) have a cold start circuit which is malfunctioning, but then why would priming the carbs resolve the problem? Could this be related to vacuum in any way?

TIA

73 3.0 CS

 

[Malc]

Hello,
Do you still have a mechanical fuel pump (your on carbs)??
If so it could be that you have a small air leak in the fuel plumbing somewhere.
What could be happening is as the car sits the fuel in the line drains back to the tank and thus when you crank the engine it's trying to draw petrol all the way from the tank.
Tipping fuel down the carbs allows the pump to work fast enough to draw the fuel up to prime the pump again...
Suggestions

1).. Check the fuel pump diaphram and internal filter (some have them some don't)
2)... Check all the fuel lines etc
3) Take the cam cover off and if possible lever the fuel pump arm up and down, can you "feel" there is petrol there or is it "dry"?
4)...On check could be to fire the car up, let it run for just a few seconds and then try again - does it start without having to tip petrol in?

Malc