The Stovebolt Site Forums The Shop Area Engine Shop 235 can't tune to save my life

I've spent all day attempting to get the 235 in my 54 to run right. What it is doing is missing erratically during acceleration and idle both- acts kinda like a lean condition. I've subbed carburetors, coils, distributors off my other 54 that runs just fine with no success. Timing is set properly too.

The only time I'm able to get it to run "right" is when I put my hand over the air horn on the carb... then the engine settles down and stops missing, and the idle speed picks up significantly. Vacuum leak? All common sense says that 'this shouldn't be'

What's the best thing to use to check for leaks around the intake gaskets?

A little history on the problem. The engine ran find until I had to remove it to change the torque converter. While it was out, I steam cleaned and painted everything... engine bay, engine, manifolds, and accessories. The manifold was replaced as well because I found the a crack on the old exhaust manifold so I tossed it out back and used another manifold I had laying around. Visually it looks okay, but also how could I tell if there was a vacuum leak into the exhaust in the riser area?

I'm ready to be taken back to school here.

It does sound like a vacuum leak. One way to check for a leak is to spray carb cleaner around your gasket area. If the truck's idle picks up, then it is sucking the fluid in at that leak point.

Take the burner nozzle off a Propane torch, and substitute a 2-foot piece of rubber hose. Turn a little gas on, and use the end of the hose to probe for vacuum leaks. It's more exact, and less messy than spraying carb cleaner all over a freshly-painted engine compartment.
Jerry

I've found the intake alignmen sleeves/rings can get out of position and cause a vacuum leak. You might want to make sure your distributor cap and coil doesn't have some moisture from pressure washing. My vote vacuum leak.