Recently had a date correct carb rebuilt by Sparky for my 442. It has had a "dead spot" and a bit of "chugging" at cruising speed. If you have your foot into it or the secondaries engaged it pulls nice and hard...as it should.

A buddy of mine who is a big GTO guy (and a better carb guy than I) checked it out. He dialed it in better (mixture wise, etc) and said he believes the issue is that the primaries may be too lean, thus needing to try larger jetting.

I tend to agree as it definetly prefer "more gas" and is acting up at the lightest points of pedal pressure.

Thought I'd see what you guys think before pulling the carb.

Thanks

 

Ask "Sparky" what he thinks.

Norm

 

You're sure it's not vacuum advance related?

 

is your engine completely stock and did you tell sparky what mods were done to the engine? some mods will have little to no affect on the carb but others will. if you have a different cam that pulls a different vacuum he will need you to take a couple different vacuum readings at a couple rpm ranges. i would say call him first. he has a warranty with his carb service.

 

Thanks.

I did speak with Sparky a while ago, should call him back. He thougt it needed mixture tuned better and perhaps a vac leak. As far as mods, NO. It is bone stock. Sparky and I did discuss that the motor was out of an automatic but we would jet it to stock 4 speed calibration.

I'll see what he says...

 

I had the same troubles, It ended up being a vacuum leak because the fuel canister was plugged into the wrong port, double check all vacuum ports. Check the timing and adjust the idle mixtures it could be lean.

 

It does sound like a lean condition and as everyone pointed out that can be caused by a vacuum leak....... One way to test this is to unhook and plug ALL vacuum lines attached to the carb and the intake manifold....This includes the power brakes...... Then take it for a drive and see if it fixes the problem... If this does not fix it then check with SParky, he's good on the carb.

 

Finally got this solved...I've obviously just been living with it for too long. Had the carb rebuilt by Cliff Ruggles, turns out all the internals were for a small block...thus, why my 455 was "chugging" - starving for fuel. Runs great now!! Should have done it earlier.