my bug is fluttering, help please.

'78 Vert should be Fuel Injected.

Can you confirm that it is?

The symptoms you describe could be due to many, many causes; best to start with the very basic stuff. Plugs, points, cap/rotor, plug wires...

This engine should have dual vac (advance/retard) distributor; if so it has 2 hoses. Can you confirm this? I would check that both vacuum diaphragms are *actually* working and not leaking. (Suck on hose- advance should move to stop) Then move on to timing setting and perhaps valve adj/compression test.

If it *is* FI, tiny vacuum leaks at the many hoses and fittings can cause major problems.

Come back with some more info and what you find on these checks.

Speedy Jim

I should have added that fuel starvation could be a factor too. Clogged filter (at the electric fuel pump) or clogged tank outlet. Less likely is a blocked tank vent.

Speedy Jim

Otherwise, what about clogged jets on the carb? Actually, if he got watery fuel, the water would cause starvation in a paper filter (happened to me a time or two)

My car also had that when it had an old "mud dauber"'s nest in the inside (top) of the air filter (unbeknownst to me) and the nest would occasionally block off the air intake. It would take MILES for my car's little 40 hp motor to get up to 49 MPH.

It's unlikely, but you could be losing compression. Do a check just in case. Also, replace the air filter, fuel filter(s), points, rotor, cap, wires?, and set the valves. It sounds like a fuel or air problem, but it's hard to say without actually driving the car. I know you said the air filter is clean, but how clean? It doesn't have to LOOK dirty to be dirty. Do you know how old it is? If you are unsure about any of these things, replace it. The paper air filters aren't very expensive. Mine was 12 bucks. Also, I think someone else mentioned that there could be something in the air intake snorkel. A friend has found engine compartment tarboard in his before! Lastly, how's the exhast system? If yours is a fuel-injected bug, the catylitic converter may very well be clogged or ruined. This KILLS engine performance, and emissions. Unfortunately, that's not a cheap fix. Hope that's not the problem. The only way I can think to check that is to remove the cat and muffler, run the engine for a period and see how it does. Wear earlplugs.

~Anthony