Since a few weeks, when I try to pass 70 mph, or when opening the big barrels, the engine has hiccups as if fuel was not arriving to the carb. I first rebuilt the carb with a kit, and then decied to put a new one wen I saw some taps inside were damaged generating leaks. Same issue with the new carb pre tuned in factory. When pressing the pedal, power comes a few seconds, and then stops until I go below 60-70 mph. I then took the Fuel Pump out and despite I have no tester, seems good, with no leaks. Is it possible that a fuel Pump that delivers some fuel flow at certain throttle does not deliver enough when opening the gas ? o No: When taking the Pump out, I had the feeling that the seal to the engine was not in good condition. Can this have an influence on the power failure ? Or can this be a more complex issue (I know my engine burns more lubricant than normal, although not smoking at all). Thanks for your advises.
You may also want to check your pickup in the fuel tank. It may be clogged/gummed up. Your lines may be corroded on the inside if they are old and not allowing full flow. It sounds like your hitting a "wall" on your fuel flow and what is making it to the carb. The pump may be the problem, but if the rest of the fuel system is old, it may be time to take a look at redoing it.
Second that motion. I don't know if your car has the same "sock" on the tank pickup that mine did. This is a nylon or plastic type material and had degenerated in my car to the point that it was collapsing and cutting off fuel. For a while, I got the car to run ok by removing the gas cap and blowing back through the fuel line with 10-20 psi air. The real fix was to pull the tank and pickup and cut off the sock.
I'd be more concerned about the carb and distributor. What factory carb are you running, and what is your coil/distributor setup?
Thanks for this precious remarks. Liked the idea of blowing the line back. If that works, I'll go for the permanent fixing. By the way, is the Gas cap sealed on these cars, or with an air hole that could be closed and then preventing right flow ?
Clint, the carb is a 4bbl rochester freshly rebuilt by Recarb co, (any case, same symptoms appeared with the prior carb). The Engine used to run well a couple of months ago. I need to look at the distributor and the coil. What do you suggest that could have happen with these ?
By the way, if I were to replace the fuel pump, what is the propper replacement part ? Mine is a Carter, and the only number I found on it is 1958 (hope it is not the date !!!). If has a big bowl below (I would say approx 5' high). One tapped hole, one big entry for the fuel arrival hose, one smaller for the fuel return hose. My Buik manual shows picture with flat pumps. I think the steel hose may have been bended a bit to connect below the bowl, but with no certainty. Thanks for your indications.
Hmm, the carb is probably not to blame then. The coil can develop cracks in the epoxy which allows a short out in the windings. Instead of a 25000 volt coil you get an 8 or 9k volt and a much reduced spark. At higher RPMs the coil can't keep up. Additionally, an aging cap/rotor will not transmit as much spark energy at higher RPM. I have seen a similar power falloff in my own car, and it was down to poor cap/rotor. Just some extra stuff to consider if the pump fails. Hope that helps!
Guys, you've got it ! :TU: I blew back the lines from the pump to the tank, cranked, drove 50 miles.... Full, power ! :3gears: As John suggested, when the summer is back, I'll think about opening the tank for a more serious fixing. In the mean time, with my legendary patience, I stupidely ordered a full set of ignition parts (coil, condenser, distributor head, points etc...) Any case, it won't hurt the engine to get these replaced, and the US$ change rate is low (for me :grin: ). Thanks again for your precious help. :beer :beer
