Bear with me please,

So i finally got around to driving my car around and I have some problemes that maybe you guys can help me with. When i first start the car say in 70* weather and start to drive for the first 5-7 min the car acts like it wants to die if you give it more than 5/16 throttle. After that it seems to be fine when just normal driving. Now from a dead stop and nailing the throttle it will go but just realy lazy until about 2000-2200 RPM and then it screams. From a roll (i mean just foot of brake) and about 7/8 throttle it will launch hard. While at speed say 40 mph i can hit the gas and the tach goes up to 2000 RPM breaks up for a second and then start screaming. I know thats just flashing my stall but why is it breaking up. I have a 750 VS speed demon 79 in the primaires and 86 in the secondaries with a Blue pump cam in #2 hole with a 37 squirter. All of that got rid of my backfire through the carb but now it just seems like its down on power down low. Initial timing is 18* and total is 36 with all in at 3200. Its as if my car weighs 6000lbs. I greatly appreciate any help. Oh yea i have a 8.5 power valve also. Idle mix. screws are about 7/8 of a turn out each and i have about .030 transition slot up front and i cant really see the rears but i would say .010

 

Do you have the choke hooked up? The first 5-7 minutes just sounds like the engine warming up.

The other I'd guess you need a stiffer spring in the secondaries. You're a little short on stall, too, but mostly you're bogging when you nail it.

 

i will try a stiffer spring. i have th purple one now. By holley's generic chart it says it wont start opening till 1915 and not fully opened till 6950. So my question is, when i go down the 1320 are my secondaries not going to all the way if i stay under 6000rpm?

I have a little bit more info on my probleme. I was in the driveway under the hood. Looking into the carb i reved the engine. To me it looked like as soon as the pump shot started to slow and stop thats when the engine started to die. It was like rev...die..rev. Im not doubting what your saying im just trying to understand whats going on here. In park the secondaries shouldnt come into play right? Is this a pump shot probleme? I have the book "super tuning and modifying holley carburetors" and its not providing help for me on this probleme. I know that the pump shot is just a bridge to get from the idle circuit to the mains to make up for the large hole that opened in the engine.

Do I have more than one probleme here? Thank you for your time..

 

i was able to do some tuning today. I installed the black secondary spring and it still had that lazy start. I kept it in though just to try to eliminate the secondaries coming on to early. I changed my blue cam for a green cam on the pump and still did the same thing. I couldnt tell any diff. Thought about it and came to the conclusion that i need more duration without loosing my 37 shooter size. (anything smaller seemed to give me a large stumble or backfire) So i looked in my holley book and seen that the pink cam has the most duration so I installed it on hole #2, adjusted my pump arm and boom. There it was. I took off like a bat out of hell. I still have on my 26x11.5 Et streets so there was no tire spin just a good solid launch without a sluggish or lazy start. thank you for your help.

 

Wow Andy, that is awesome. I have almost the same set up as you and was told that my stall is on the low side. I also have a 37 squirter with a blue cam #2 position. I am also have some problems with the take off. It takes off well, but not like I think it should. My timing is right on and all carb adjustments are also on. Iknow the pink cam is not the proper cam, but I see some cars, with less mods than mine, take off like a bat out of hell and have the pink cam in it. I think I'll try it...thanks.