Hey, i have a mild 350 with vortec heads, flat tops, rpm air gap, 795 q jet 1 5/8 headers 2.5 exhaust, and it has a bog off idle but when i put on my friends 750 dp it doesn't bog off idle and i don't want to go to a different carb because i like the q jet any suggestion on tuning the q jet to fix this problem. I am thinking it might be the accelerator pump that is the problem if so i got one at my house i can put in.
Dont worry about the pump at first, try adjusting the secondary air valve tension first. Then if the bog still persists, hook up a multimeter to the O2 sensor(if equiped that is) and see if it's a bog from a lean or rich condition. Can post a craft if you need one.
This is just my 2 cents worth but I have dicked around with the q-jet and had some luck but the holley's just seem to kick a little more *** best of luck to you
Very difficult to tune, jet replacement nessesary for proper mix, air bleed replacement nessesary for proper mix over the RPM range. Oh and you had better have an O2 sensor or computer with that nice new holley if you have a blank spot in the RPM range and expect to tune it correctly.
Why do you think they sell the jet kits for holley's at almost every autoparts store? I wont even go into the maintenance required for those carbs...
Yeah... holley's really do kick some ***... Their own!:thumbup:
I assumed that the bog that you're talking about was when you floor it. If you're talking about when you ease into the throttle that would be a different story.
Yeah the bog is at full throttle, and i tried adjusting the secondary air valve before and it didnt seem to help i did 1/8 of a turn at a time and finally i just set it back to the stock settings because i didnt get any better. And no this vehicle doesnt have a o2 sensor
Well now you got to figure out if it's just dumping fuel, or going lean the hard way. I know the bog of the Q-jet, if you dont just MASH your foot down, it doesnt happen. Sometimes if you blip the throttle and then mash it, it doesnt happen either.
I would search for some different secondary rods and try going rich at first, if that doesnt help, then I would go lean. There are other ways to do it, but this is the first thing I would try if the air valve doesnt fix the problem. All Q-jet primaries are the same needle, from a 795CFM Q-jet off of a monte, to a 660 off an olds. At least from what I have seen, so dont worry about that.
yeah the secondarys are opening up, you can feel it when you are moving and you open up the throttle
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