Slow onset hesitation at speed

Okay. 1969 bone, stock, standard beetle would start up fine, run well, accelerate well, even up hills. After 10 or so miles, a sort of hesitation would creep in that felt like onset fuel starvation. Checked fuel filter, found rust. Replaced filter. Checked fuel, tank- found rust. Replaced fuel tank, cleaned brass filter where fuel line screws into tank.

What else is there to check? What throws me is that the beetle runs perfiectly for about the first ten miles or so and then gradually develops signs of fuel starvation. It never stops running and seems to idle fine. David

Reply to
C7eca
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Have you tried rebuilding your carburetor?

Also, check your intake manifold rubber boots. If they are cracked, they can cause air to leak in and throw off your air & fuel mixture.

Reply to
Funkie

clean, or replace, the entire fuel line too.

Reply to
bind

Can be hard to diagnose.

Before you replace any parts, try a couple of easy tests:

1) Make a hiway run with the filler cap loosened (not with a full tank). This will rule out/in a tank venting problem which can produce the symptoms you describe.

2) Make some crude measurement of flow from the fuel line. Disconnect the hose from the pump inlet. Run the hose into some suitable container and watch the flow. If needed, jack the car up to raise the tank.

If you get just a dribble, there is a clog. If there is a steady stream which doesn't diminish over time, then the system is good up to that point.

That could leave the pump as a suspect. For example, one thing that can happen is for the pushrod to bind in the bakelite stand as the engine heats up.

Speedy Jim

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Reply to
Speedy Jim

cked fuel, tank-

Thanks everybody! I'll be working on this next good weekend. David

Reply to
C7eca

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