Idle?

Stale gasoline causes problems that is for certain.

Get some fresh gas in the car and try again.

If the problem persists you may want to look at incresing the size of the idle air bleeds. On some carbs this is simple to do (screw in bleed jets) on others like old Holleys the bleeds are pressed in and must be drilled to make them bigger.

Obviously if you have to drill them it is awfully hard to make them smaller if you go too far or you find drilling them did not fix the problem.

Drilling also requires a selection of very small drills as only tiny increases in size are required.

It also requires that you know what you are doing.

Could be that your fuel line is routed to close to a heat source. I had a electric fuel pump at one time on my car and it would act like that because the pump and fuel line were
to close to the header.

What things were changed during the restoration ?

How did it run previous to the work ?

It was removed, dyno'd and reinstalled. It was test driven prior to delivery with no issues.

How long was it left sitting unused ?

4 1/2 months.

Not too long. I left a car for 12 months and all the fuel in the carb evaporated and had left a residue of varnish and gunge in the carb that required a very detailed clean internally to remove and restore the carb functioning to normal.

As first suggested try some fresh gasoline, pump the tank out if you have to and use that gas in your lawnmower.

There sounds like there is some richness going on which could be due to crud in the carb but it usually does take longer than 4/5 months.

The high float levels is a good thing to check out too.

I'm using an electric fuel pump. Pressure at the carb is around 4-5 psig. As I recall this is a good pressure for a holley.

Aus Ford,
Ran alright today but is definitely rich. Just ordered Michael Haas' (No Quarter) tuning book. We'll see what he has to say.

quote:

Originally posted by Husker:
Aus Ford,
Ran alright today but is definitely rich. Just ordered Michael Haas' (No Quarter) tuning book. We'll see what he has to say.

Where is it rich ?

At idle ?

During acceleration ?

Part throttle ?

Full throttle ?

All the time ?

All the time. When I parked it smelled like I dumped gas on the floor. Saw no level in either bowl. I'll pull it and start exploring.

Yes take it off and strip it down.

Clean, inspect and make adjustment of the floats.
Also take note of what size jets you have.

What carb is it ? What size ? Vacuum or mechanical secondary ?

deteriorated power valves create a direct path from the fuel bowl to the base plate & intake plenum

Actually, the older Holleys could break the Power Valve diaphragm with a backfire. The newer ones have a mechanism (a caged ball bearing) that prevents this.

But a power valve could fail with age as well....

Rocky