VCCA Home Forums TECHNICAL - 1945 AND NEWER 1958-1960 Hesitation on acceleratiom in 59

My 59 has a 283 with a 4 barrel and Powerglide , when I come to a corner and stop it wants to hesitate on accelleration sometimes cuts out
Any clues

Most common cause is the carburetor pump plunger.It should squirt a little stream of gas upon "stepping on the gas pedal" to help the engine to pick-up speed.If not working correctly the engine will hesitate.
Depending on what make of 4 barrel you have on your 1959, they came with both a Rochester or Carter, The pump itself may need replacing or the jets may that the fuel squirts out of may be restricted or a passage plugged or a check ball stuck.

Thanks , I thought that might have been there I'll pull it down
dave

The pump plunger is probably an easy and likely place to start. I was reading somewhere recently (might have been in "Hemmings Classic Car" magazine) that modern cleaning additives in gasoline can break down the rubber on the plunger. Also, if it's the original plunger, it may be made of leather instead of rubber, which can get dried out and shrink. In either case, I think the plunger can be replaced in about 30 minutes without pulling the carb off the motor - at least for the Rochester 4GC on my '58.

If you end up having to pull the carb to rebuild or whatever, be sure to use the specs in your Chevy shop manual and if you can, get the manufacturer's manual for the carb as well. Having both helped me to understand the adjustment procedures a lot better.

Matt Joseph describes in "the Classic Car Restoration Bible" how carburetors have long been the least understood and most tampered-with components on most cars. Over the years, one guy after another may have made "adjustments" with just a screwdriver and his ear, putting everything more out of whack with every twist. I saw this to be true on my 4GC, as I went through the manual's adjustments one by one and saw how far off everything was. No wonder it ran so poorly and always smelled like gas! Not any more though!

WHERE IS THE FLOAT SET? ALSO SOME MMO IN THE TANK WON'T HURT THE LEATHER OR RUBBER PLUNGER.

Your timing could also need looking at.

The carbie is a Rochester 4 jet, I'll start with the pump plunger, when you buy a kit for the carbie does it come with the plunger complete?

Yes - but the spring and retainer for it are transfered from the old pump.Also make sure that the pump nozzle holes are clean.The little cluster sits on top of the carb. throat (front 2 barrels) and has a jet that squirts gas ot to each barrel.One could be restriced with dirt as they are very small.Before you take anything apart remove the air cleaner and watch and see if both are squirting.Even with a bad plunger some gas should be seen coming out of both.

I've downloaded a GM manual for the Rochester, I assume my carbie is a 4GC ?? are all 4GC the same I have seem the kits advertised on EBay for Buicks , are they the same carbies/

Check the triangular aluminum tag attached to one of the securing screws for the air horn assembly on top of the carb. If it's a 4GC it should have one of the following numbers on it (3-digit numbers use the first 4 digits of the previously listed number): 7008737, 7009846, 7012126, 128, 7013004, 010, 7015004, 010, 7019004, 010, 014. Those are the 4GC model numbers used for the 283 from '56 to '61. If the tag is gone that will make it tougher, but you should be able to ID the carb from photos.

It looks from this source like all other options for the 283 are either 2-barrel or multi-two barrel power-pack or tri-power setups. I found this list on the following site:
http://www.carburetion.com/Kits/chevy.htm

There is JET carbie kit for sale on EBay are these any good