Automotive Forums  Where Car Enthusiasts Go to Discuss Cars Online

I just rebuilt my carburetor, a 2-barrel Rochester. It's on a 400 ci V8.

All that's on this carb is an automatic choke, a choke pull-off, an idle-stop solenoid. Involved in this may be a vacuum-driven timing advance control that goes to the bottom of the distributor & a vacuum line running to the transmission.

The motor idles well choked / cold. I've balanced the needle screws, runs smooth.

When it warms up the motor stalls & idles rougher & rougher, so I've had to set the idle screw (hitting the accel. throttle cam) a tad high.

If it's rolling & idling steady in neutral & I brake fast using only the emergency (manual) brake, the motor stalls!

It doesn't always stall, however, like when I stop going up a slight rise. The motor also surges in cycles, particularly during idle, and there's a really jerky transition between idle & higher speeds.

I'm beginning to suspect my float is set too low, closing off the fuel early (not enough gas in the bowl). Would that explain the surging (fuel pumps pump in spurts) & the leap between idle & acceleration? When I did the rebuild I replaced all the gaskets (found a vacuum galley leak) & just the fuel bowl accelerator pump, but I left the float level alone (didn't check it either!).

I'm also wondering if the timing advance (vacuum driven) could be involved in this (apparently the timing advance vacuum line had been disconnected & screwed shut for a long time).

I've checked the heater riser & PCV valves, they're open. I haven't checked for vacuum leaks yet, but that'll be next along w/ testing the choke pull off, the idle stop solenoid, the distributor timing advance widget, etc.

Thanks in advance!

/lee  

it sounds like you need a adjustment on that carburetor