Technical Holley 94 sputter

I had rebuilt my 94 incorrectly, so instead of dying I figured I'd take it to a well know local carb shop for a good once over. Once installed, the car started and idled great (better than it had before). However, I noticed that when I give it lots of gas, the old girl sputters and even spits (out of the carb w/o a cleaner on it). I've searched the threads but didn't see anything that related to this. Any thoughts?
As always, thanks.

Michael

 

anyone?

 

OK, I'll bite. From what you describe it sounds like when you open the throttle, you get a rush of air but not enough fuel to make the correct air/fuel ratio. You have come off the idle circuit ( which seems to be ok) and you pass the off-idle circuit to the main venturis. To do so you need a squirt of fuel to satisfy the rush of oncoming air. I'm going to guess that your accelerator pump may be not working or when rebuilding the carb they didn't get all the fuel passages blown out. To check the accelerator pump, just work the throttle while looking down the bores of the carb. If you see a good squirt of fuel into each bore, then it is probably ok. You should take it back to the rebuilder because it shouldn't be like this.
I love these old carbs but they do have several potential problems. They are notorious for having needle valve problems because they can't handle more that 2-3 psi of pressure from the pump, they have problems with the power valves blowing out or not fitting properly and they often leak from worn out throttle shaft bushings. Hope I didn't add to your confusion. I always say that 90% of a repair is just finding out what it is that you need to fix.

 

X2 everything Ol' Blue said.

 

I used info from this page to help with my old vw, just general reasons why it happens... read the reasons and started eliminating them one by one. I still had it bookmarked in a folder.

 

Thanks for the great feedback. Was kinda thinking it was the accel pump. I'll do some checking and see what happens. Thanks for taking the time with a noob.

 

Random thought...since I converted to 12v, I didn't change the 6v fuel pump. Works fine (just pumps more). Could this be a possible cause of the sputtering issue? Since the standard needles aren't meant to handle more than 2-3 psi, maybe the extra volume is causing some flow issues. Would a needle change fix this? Or maybe replace the electric pump with a 12v version?