Stalling at idle

[Lawrie]

I have been working on my friends 28 A for some months on and off trying to get to the bottom of a stalling problem.
The car would run as sweet as on the highway or around town, but when coming to a stop at lights or the like it would falter and most time stall.
Car has a B carb,
I tied a different carb that ran well on another car, but still had the stalling on the 28 A.
I tried making sure the carb and manifold faces were nice and true, fitted different types of manifold to engine gaskets, all to no avail.
set the engine idle at 480 rpm, all with no difference.
The car has just done about 900 KLm since I last tried to sort it out ,(Cheryl, the owner, has done very well to drive with the stalling issue )
its back in my shed,
So the last couple of days I got back to sorting it out,
I try another good running B carb loaned from a friend, same issue,I take the inlet manifold off to recheck the faces and fit another new gasket,
Looking for cracks or something on the manifold,I see, someone has drilled about a 1/2 in hole through the top of the curved part and brazed a small brass cap over it, and this was cracked, pouring some brake fluid into the manifold it leaked out around the joint.
I replaced the manifold with a spare one and the stalling problem has gone.
Many thanks to David Renner who told me stalling is caused by air leaks.and pointed me in the right direction
Lawrie

 

[Jim/GA]

Yes, David knows his stuff.

I will file that one away in my list of possible causes of stalling.

 

[old31]

What is that intake from? It has a square throat and a vacuum inlet at 1 oclock.

 

[Benson]

Yes and a leaking Windshield wiper MOTOR on 30 - 31 and / or missing hose or leaking hose going to wiper motor. Very common for causing stalling.

 

[Synchro909]

What is that intake from? It has a square throat and a vacuum inlet at 1 oclock.

That is not a vacuum inlet at 1 O'Clock - it is a post on which a bell crank is mounted for the ignition timing. It is on all RHD manifolds.

 

[Trapdoor2]

I'm in the same boat, chasing vacuum leaks. I just pulled my manifold group last night and YIKES! I don't think the gaskets have been seen for 50yrs. Those things just crumbled off of the block in bits and pieces. Only the intake bits hung together a little. Glad I bought new gaskets, studs, nuts, etc., a while back. I should have it all back together this evening.

Good news: the block and manifold sealing surfaces look good. No rusty bits and the manifolds show machine work (flycutting). A straightedge shows them to be in good order.

Marginal news: the intake to exhaust manifold bolts are very, very rusty. I may just leave them be for now.

I did find that my vacuum port in the intake manifold was loose. A bit of tightening smoothed out the carb a bit. I'm going to cap it off temporarily as I put things back together. Once I get the manifold vacuum leaks sorted, I'll sort out the wiper system.