Im sure youre right, I just know Im trying to find a vacuum leak and then I hear whooshing air, so I was a little concerned.
The sound is normal when opening the throttle. The connections at A and E are both manifold vacuum. They would produce the same readings. 13" of VACUUM (not pressure) sounds a little low to me for a cam with only 212* of intake duration. Was the cam degreed in when installed? Has the engine always hesitated for as long as you have owned it? Did it ever run well for you?
I dont know about the cam being degreed, I cant imagine it wasnt though. My dad has assembled circle track race motors for 20 years so it's not like this was his first rodeo (he is the one that assembled this motor.) I think its safe to say the engine has hesitated everysince and before the rebuild. I just always chalked it up to a poorly tuned carb and or timing. Make no mistake- the motor is VERY strong minus this slight hesitation with light acceleration.
Well, The first thing I would check is the accelerator pump. With the engine off, look down the primary side of the carb, and briskly open the throttle. You should see 2 streams of fuel shoot out and strike the venturi of the carb on each side. The second thing I would check is the timing. What timing does the engine idle at, and does the mechanical timing advance with rising engine RPM? Is all the timing in by 2500 RPM? What is the total timing? Have you read my timing thread? http://www.v8buick.com/showthread.php?t=63475
Does the car need to be running for me to be able to see the fuel shoot out or can I do it while the car is shut off. If I do not see any or much fuel coming out where is the acc pump on the carb and how hard is it to replace? That timing thread, whoa, thats alot of VERY good info obvously- but it might be a little over my head.
Engine should be off. The accelerator pump is at the front of the carb. There is a small piston that operates in cylinder to push fuel out as you open the throttle. I made that timing thread as simple as possible. It is certainly not above your head if you read up on basic auto mechanics. If you have a Buick chassis manual, you can read the ignition chapter. It does a very good job of explaining the basics. If not, you have a computer. Put ignition timing into Google and start reading. Ask questions about what you do not understand. Here is something I found. http://www.socalsacc.com/Ignition Timing.htm
By no means was I putting down your instructions- Im just afraid of de-tuning the car when it already runs damn good right now. Im just trying to get that liiiiiiiittle extra out of it. Im sure I can handle it. I dont think it is a timing issue though, it really feels fuel related. Ill check the acc pump tomorrow. How obvious is the gas shooting out? I dont remember seeing or hearing any gas spraying today when I was tinkering with it. Would that going bad cause it to be very hard to start when the engine is cold?
Good advice so far. Regarding q-jets in general, here's some good reading from a well respected tuner: http://www.digitalcorvettes.com/forums/showthread.php?t=88376 Don't discount Larry's thread...power timing should be taken care of first, carburetor tuning can work its way in later as long as part and wise open throttle carb performance is acceptable. If timing is off, it can act just like a carb problem and you end up running in circles forever. Devon
Okay, pulled the breather assembly off and used my Itouch as a flashlight, crawled in the wheel well and hovered over the carb as I snapped the linkage back a few times. I was able to see fuel come out and go into the venturi. It defintly did not shoot out and hit the venturi- I would say it sprayed/misted out of the holes it was coming from, sometimes it barely came out at all. I was invisioning a forcefull stream by the way you described it and that did not happen.
