Tuning help

[PeteLeathersac]

Before you dig into the carb, are you positive you don't have a vacuum leak anywhere?.
Besides checking lines, fittings, advance system components plus power brake and modulator parts if applicable, I seem to recall some Oldsies had a ported point on top of the intake that required a sealed bolt intstalled if unused?.

Always tough replicating problems in the shop that only show up driving under load at certain revs but if a manual inspection of the components show nothing amiss, sometimes intake leaks can be found at stand-still by hooking up a remote tach and trying different constant revs while keeping a close eye on the tach for variations as you mist methal-hydrate out of a spritzer bottle onto suspect vacuum areas...be careful of course and keep a fire extinguisher at hand!.

May be best if equipped to isolate brake boost and modulator system parts out of the equation and doing a drive first just in case...then onto the other things?.
Good luck!.

~ Pete

[JOZW30]

You guys are awesome! Thanks so much for the advice!!

I will re-check my vacuum to be sure before messing with anything else.

I re-built the carb before finishing the motor. It's really clean.

Car has the correct manual disc brake set-up mandatory with the 4-speed W30 package.

Eric, I will double check the obvious and make sure my basic timing is good. If I still have this issue, I'll try your advice above. After that I'll contact you privately for some "professional" help.

I really think this car can run alot better than my limited exp./skills can manage. But I love learning too.

Thanks again!

[SmallHurst]

Also, check to see if the vacuum advance is working properly. It could be that you have a leak in the canister and it does not show itself until the advance is needed. Pull a vacuum on the canister and see if it advances the weights like it should. Personally, when I am at the track, the advance is unhooked so that it has no possibility of coming into play. (Not like it would have a chance under a full throttle blast!)