My Tractor Forum banner

Dead spot in carb?

3694 Views 5 Replies 5 Participants Last post by  Justin Helterbrand
I just bought a Holley 670 Truck Avenger carb for the 350 small block in my truck. the carb starts and runs great but when you give it gas it has a bad dead spot. When you give it gas it sounds like its going to die but when you let off it catches right back off and is fine. If you fire on it real quick it doesent seem to do it. Anyone know what could be causing this?
1 - 6 of 6 Posts
With engine off, and air cleaner removed work the throttle linkage at least halfway thru. You should see some gas squirt into the venturies from the accelerator pump. If not it's more than likely the problem.
Mike
Check also that your manifold heat passage is open. A cold manifold will also give that symptom, even if the accelerator pump is working.
What type of intake, stock or aftermarket? How long has it been on there?
Sounds like a blockage or possibly accelerator pump needing adjusting. They are usually set okay right out of the box, but may need adjustment
What type of intake, stock or aftermarket? How long has it been on there?
Sounds like a blockage or possibly accelerator pump needing adjusting. They are usually set okay right out of the box, but may need adjustment
An air leak could also cause this.. Check mating surfaces. Low fuel level in the bowl limiting the high speed jets could also cause starvation or what you are experiencing. Blocked / plugged main jets? Once it speeds up, how is the engine's power? So many questions but start with the accelerator pump then investigate further. The instructions that came with the carb should tell you how to set it up.. Just some thoughts for ya..:trink40:
We are almost positive that it just needs adjusted. We tweaked with it alittle bit when we first put it on. Once it gets past the dead spot it has tons of power. Its alot more powerful with the Holley than it was with the old QuadraJet.
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top