Rochester 2GC carb

[zy5 guy]

When I bought my truck it had an Edelbrock intake and a Quadrajet. I started having a lot of problems with it so I had someone replace it with a reman Rochester 2GC and a stock intake. The person who installed it did not have it properly adjusted (running rich and frequently flooding), so today a friend and I removed it from the truck and disassembled it. We set the float level and drop per the specs in the shop manual. We also adjusted the idle mixture screws and the idle speed using a tach to help get it dialed in properly. Truck starts, idles, and drives great overall, much better than before. However, I still have one problem. When you punch the gas, it stumbles under hard acceleration like it is starving for fuel. If you're easy with the accelerator pedal it does just fine. We did make sure the accelerator pump was moving freely once we reinstalled the air horn. We did not do any timing adjustments to the engine. Are there any adjustments I should be looking at on the accelerator pump? What else should I be looking at? I do know that I have a very slight fuel drip from the fuel line at the fitting where it meets the carb which I will be fixing ASAP. Truck is a 77 C10 with a 305, auto, and light duty emissions. Below is a pic of what I am working with.
Thanks,
Evan

[geezer#99]

Easy to check the accelerator pump. Look in the carb and stroke the throttle. See how much fuel is pushed in.
But first check your timing.
What's your initial timing set at?

[Dead Parrot]

If the running rich and flooding went on very long, it is very possible your problem is simply a buildup of carbon in the cylinders and on the plugs. That can cause the problem you describe. Get the truck up to highway speed for 20 or 30 miles then romp on it a few times.

I noticed your EGR valve is not hooked up in the picture. If that is normal, make sure it isn't stuck part open.

Make sure your vacuum advance on the distributor is hooked to manifold vacuum.

[Old Truck Man]

It was common for a 2GC to have a flat spot when in transition from idle circuit to main jets. If it really bad you might want to check out the powervalve you might have the wrong size. also the rod that actuated the power valve that cones down from the carb top might be sticking it works off manifold vacuum.

[zy5 guy]

Thanks for the replies. I currently do not know what the timing is set at, I'll have to borrow a timing light to check that. The EGR has not been hooked up since this carb was installed, and when I was running an Edelbrock intake before it did not have an EGR either. It has never ran right since it has been installed though so I'm going to try to hook it up to see if there is any difference or not. I believe I do have a schematic of the vacuum hose routing in the shop manual. I would not be surprised if there is carbon buildup, and I'm going to pull a few plugs to see what they look like and change if needed. The vac. advance on the distributor is hooked up to the right front of the carb at the base (right front if you're sitting in the driver seat), and is visible in the picture. Again I will check to see if I have the proper routing. When I was doing some research last night one of the things that came up was the power valve, specifically the rod that is mounted in the air horn. I did not check to see if it moved freely, but I believe it should move up and down slightly. Again thanks for all of the ideas.