holley carb...what the f^&%

[the fall guy]

I installed a holley 670 street avenger on my 85 blazer 305ci. The only problem is that now i have to wait a good 5 to 10 min before i can even drive the thing because it keeps stalling out or back firing. My choke is fine and so is my idle mixture and vacuum lines. Can it be the carb is too big or the air pump(it is still connected) /forums/images/graemlins/angryfire.gif /forums/images/graemlins/k5.gif
p.s. The engine is stock as well as the exhaust.

 

[Twiz]

[ QUOTE ]
The only problem is that now i have to wait a good 5 to 10 min before i can even drive the thing because it keeps stalling out or back firing.

[/ QUOTE ]

In the middle of summer? I'd take a closer look at the choke, just to be sure.
Otherwise;
Backfireing through the carb or the exhaust? Though the carb - it's lean. Through the exhaust - it's rich. (rule of thumb)
If it's poping through the carb, when does it happen? Off-idle? Tip in throttle? Wide open? Knowing the throttle position, will help zero in on what circut to look at.
If it's Backfireing through the exhaust, are you sure the choke is pulling off correctly?


It's difficult to diag one over the net - ya-know. Every lil bit of info can help. Otherwise, you just get "hip-shots".

 

[mrk5]

Did you change plug wires? I've had something similar happen from getting plug wires on wrong.

Don't know if that will help or not, but I thought I would throw it out there.

The only other things I can think of, besides those previously mentioned, is to make sure carb is securely bolted on.

 

[4X4HIGH]

A backfire through the carb can blow a power valve and make it run rich.

 

[backcountry]

Carb is a little to big for that motor unless it has alot of mods and is set up for high rpm's

Alot of people over carb their engines.
The speed at witch air enters the carb is very important. The larger the openings the lower the speed.

Simular to exhaust systems. Usually the quicker the exhaust exits, the better.

Here are a few links for you to check out.
http://www.chevyhiperformance.com/techarticles/148_0403_choose/

http://www.classictruckshop.com/garage/shopmathcfm1.asp

/forums/images/graemlins/peace.gif