Just bought a 70 Chevelle SS 396 that has a warmed up 69 396 325hp motor.I was told it had about 15k on rebuild and it probably is true from the looks of the motor and the performance. The rebuild included an Edlebrock cam/kit,Performer RPM manifold,Eldebrock Qjet carb,750 I think and headers.Problem is a serious bog when you try to accelerate fast,in fact with the car in drive with brake on I can give the throttle a quick tap and usually the engine dies. I am a Holley carb guy and don't know squat about qjets but the carb and intake look pretty new so I'm not ready to just dump them. Any ideas/help would be appreciated.For my sake use the KISS principle. Thanks Jake

There are many people who can help dont get rid of it just yet. Most likely if you have ruled out other problems, the biggest culprit on q-jets is that the secondaries open too soon. they are tuneable! your can fiddle with it, but i suggest you get a book on the subject. they are great carbs. I type too slow to offer tuning instructions. but have you check all the basics. Timing, Compression, Fuel Quality and pressure?

With the engine off look down into the top of the carb & work the throttle a couple of times. You should see a pretty good shot of fuel, if not the acel. pump cup is probably shot.

Jim

I love Q-jets. You just have to understand the beast.....

Several things come to mind:

1)Like Jim said, check the accelerator pump. First thing to do is, with the engine off and carb primed, flip the throttle and see if the accel pump is actually moving and squirting gas. The pump needs to start moving as soon as the throttle starts moving.

2)The accelerator pump Rod might be installed in the wrong hole. There are two holes in the accel pump lever arm........the outer hole produces a leaner pump shot and can cause a bog or hesitation. The inner hole is the richer shot and should be used on most performance applications.

3)A stuck accelerator pump check ball can cause your problem. If the carb has been sitting for a while or there is trash in the carb, a jammed/stuck check ball will prevent any accelerator pump shot.

Good luck! graemlins/thumbsup.gif