Pudder at high speed

[Chazwars]

Always learning and didn't see a post.

72 with a DMSA upgrade.

I've got the carb tuned back to factory settings. The plugs are showing a very nice light brown tone after running 75 miles on the adjusted carb. Everything runs smooth as butter. Then, after running at approx 75mph and 3900 rpm, the engine starts to Pudder and feels like it is starved for fuel. When I let off the gas for 2 sec or so, it kicks back into smooth driving. Then a few minutes later, it does it again. I readjusted the carb and still the same issue. One thing I should mention is that my temp sending unit and gauge is cooked and I'm waiting for new parts. The car runs at 195 degrees and never higher, even running hard in 90 degree direct sunlight temps.

[DanD]

Sounds like you are not getting enough fuel from the pump or line. The carb is probably fine.

[bradartigue]

Sounds like you are not getting enough fuel from the pump or line. The carb is probably fine.

Check fuel delivery as DanD noted. If that is in the 3-4psi range (meaning the thing is flowing, I don't think you need a gauge). If that's okay then open the carb lid and look for rust in the float bowl. If it is there then clean it out and clean out your fuel tank. Then install a good filter (king filter or equivalent).

[Chazwars]

Solution: crap fram fuel filter. Turns out the paper expands exponentially in humid weather (85-90%). Replaced with a Wix and readjusted carb back to factory. Now I've got 3.5 psi at idle with largest drop being 2.5 in fourth gear at 4100rpm and 60mph.

Steady as she goes. For now.