Faltering at Higher Speeds

[mxp01]

All:

I've got a 59 BE with a base 948 and S1 carbs. When I drive at high speeds the car will begin to falter, like it wants to stall. I then back off the speed and it recovers and I can continue cruising at a lower speed. The car seems to perform fine at anything below 50 mph.

Thoughts?

Mike Pennell

 

[nomad]

Consider cutting the engine and kicking the clutch when it does it. Lift the cover off a carb an see if its getting a proper supply of fuel. I have a car doing similiar things and am blaming it on a weak fuel pump or not enough air getting into the tank through the vented cap. I have a later hose and cap on that car with a hole drilled in the cap to supply the tank with air.

Kurt.

 

[SaxMan]

I know when my carbs have been out of sync with each other, I'd get faltering in the 2000 - 2500 rpm range, but then it cleared up at higher revs.

 

[regularman]

It could be the fuel pump not flowing enough. Higher speed more fuel. I went through that once.

 

[Bayless]

Be sure to check any filters. My old Mercedes got where it would run all day at 60 but push it up to 61 and it would stall in about 15 seconds. I replaced the filter and serviced and tested the pump which didn't help. Finally found out there was a fine mesh screen inside the tank that was thoroughly clogged.

 

[LarryK]

Check dwell.

 

[bobhustead]

Left field possibility that I had on the TR3 I had as a teen. If the spring on the points weakens due to fatigue or heat (like from leaving the switch on for long while not running) the points will float at high rpm, not closing.
Bob

 

[Joe Schlosser]

50 mph with BE rear is about 3500 rpm. Not real high revs
Start with fuel flow. Clogged filter/line or weak pump. Is the fuel tank original?? Source of a lot of particulates that can clog bits
Find a place where you can kill the engine at high rpms and check the level in the bowls. As you have a mechanical fuel pump you need to go right to neutral so the engine stops quickly so you can get a good reading