Expert: Brad Sears - 6/29/2009

Question
QUESTION: on a recent trip  with my 57 Bel Air I started to experience  an engine cutting out condition as if it were starving for fuel or the ignition was cutting in and out.It got worse as it got hotter and would only operate normal at lower speeds up to 35 mph.If the vehicle stalled it would start right up again. It is original 283 w/2 barrel.I changed new carb ,coil, resistor on fire wall,new plugs,new fuel pump.Removed gas cap in case of vapor lock condition.Timing is right on. I'm still experiencing the same problem.The motor has 105k original miles on it. Recently I removed old blowby pipe and installed a pcv valve which I routed back to the base of the carb in order to eliminate blowby smoke and fumes into the car when sitting at a light. Could this be creating my problem by possibly restricting crankcase ventilation ? If not what could be the problem ? Any help would be appreciated. Thanks...Bobby

ANSWER: The PCV would not cause this and is a good move. I did not notice a fuel filter in the list of things that you replaced. Did you replace the filter? I would then have a fuel pump pressure and volume test made on the car. Let me know.
Brad

---------- FOLLOW-UP ----------

QUESTION: Brad, yes I forgot to mention I also replaced fuel filter.I changed the entire glass bowl with a new one,eliminated the stone filter for new paper element making sure its in the right direction,new gasket & made sure it was not sucking air.I have to tell you this is 3rd new fuel pump. Perhaps I have a problem with line from fuel tank to pump. What do you think ?

Answer
I think that I would do a vacuum check on the pump and the line. Disconnect the line from the tank to the pump at the pump. Attach a vacuum gage to the inlet side of the pump. Crank or start the engine and read the vacuum gage. It should show 11 inches of vacuum. If the vacuum is low it could a worn fuel pump push rod or cam lobe. Then if the vacuum is ok, re attach the line to the fuel pump and disconnect the line at the tank. Attach the vacuum gage to the line and run or crank the engine. The vacuum reading should be the same as at the pump and should hold for about a half a minute. If not then there is an air leak in the fuel line breaking the vacuum and thus the flow of fuel. Let me know.
Brad