Q jet help please

Hello I got my 1977 400 running good thanks to your help. I put a comp. cam xe262 and # 16 heads and headers, still have the stock Q jet on it. The motor runs good and sounds good but when I give it full throttle it doesnt seem like all 4 barrells are kicking in. I was wondering if there is a test I can do to see if the secondaries are opening up. IT goes good to 60 but it doesnt seem to really kick in to do it. thanks again for any help.  

q jets have mechanical lower secondary throttle blades...     is the choke blade on the primary opening full... if not..

hanging on one of the studs that mounts the choke thermostat assy to the side of the float bowl is a little rocker lever...  this locks out the secondary throttle blades if the choke is closed... any...

you can with the engine off....  hold open the choke blade... and move the throttle wide open and then with your third hand... open the secondary butterflys and see if the secondary throttle blades are wide open...

you have to look inside... the throttle linkage on the drivers side is spring loaded... so it will look like its moving when the blades are actually locked shut...

the secondary air door blades might also be hanging up.....   see that they open with your fingers... with some resistance...  there is a tiny spring to close them that is adjustable... on a 77 the primary vacuum advance may also have a long rod that limits the opening speed of the air doors...

there is one thing...  one has to be careful of... that before you open the secondary throttle blades... that you climb up on top and open the air doors... look down inside to make sure there is no trash sitting there waiting to be dropped into the motor...  

additional... here are some q jet articles scattered around the different magazines...

knowledge is power..

http://www.circletrack.com/techarticles/ctrp_0607_quadrajet_tech/index.html

http://www.hotrod.com/techarticles/engine/edelbrocks_q_jet_carburetor_replacment/index.html

this one covers the electronic version.. but mostly the mechanicals...

http://www.carcraft.com/techarticles/ccrp_0908_qjet_carburetor_rebuild/index.html

anybody who even thinks of owning a q jet.. needs to read and book mark these articals


http://www.superchevy.com/technical/engines_drivetrain/induction_poweradders/sucp_0012_gm_rochester_quadrajet

http://www.chevyhiperformance.com/projectbuild/148_0403_1974_chevy_camaro_z28_quadrajet

http://www.chevyhiperformance.com/techarticles/49860_rochester_quadrajet_carburetor

http://www.chevyhiperformance.com/techarticles/0606ch_jet_performance_products

http://www.popularhotrodding.com/tech/0802phr_how_carburetors_work