losing power on hills

[123finboy]

My '58 352 with a cruise-o-matic drives fine on the straight away, but loses power on the hills. I have to down shift to low, but still have reduced power. Could this be a failing fuel pump, or something else? Would appreciate any advice. Thanks.

[Ford Only]

I doubt if the fuel pump would do that, you would probably have stumbling or sort of a engine miss if the fuel pump was not delivering enough fuel.
You can check the fuel pump with a pressure gauge, should read over 4lb or real close. another test would be to do a flow test this can be done by starting the engine to make sure the carburetor is full then shut the engine off disconnect the fuel line put a hose on the end of the line or have a friend with container that they can place to catch the fuel, start the engine and let it run long enough to check the flow or till you run the gas out of the carburetor just make sure that you won't splash any fuel as it comes out, you should have steady flow.
I don't think that its the fuel pump though, sounds like it could be plugged main jets in the carburetor or the distributor is out of time due to point adjustment and or no vacuum advance.
You didn't say if this happened suddenly or over a period of time, this could be your engine is getting tired and in need of a overhaul.

[123finboy]

It happened suddenly, just after adding gas at a reputable gas station [Chevron]. Can the jets be unclogged with a gas tank additive? One other symptom is that when I'm losing power, I hear intermittent pre-ignition pinging. I always use 91 octane, but could it be bad gas? Or maybe engine timing? I really appreciate your response.

[Ford Only]

If it happened that suddenly I doubt if it would be the main jets but if you want to check them you would need to take the top of your carburetor off (stock Ford carburetor), they are at the bottom of the bowl, additives will not work.
I suspect bad gas or timing issues, if you have points you need to check them to see if they are properly adjusted, if the are pitted or not adjusted correct it will affect the timing.

[123finboy]

Thanks, that great advice. I'll keep you posted.
123finboy.

[123finboy]

Update: it was probably bad gas. I drove it long enough to use up half a tank, then filled it up with Mobil premium, and it drove better. Kept adding gas as I burned more, and it got better still. Thanks for all the advice.