AP Diaphragm

1 reply to this topic
  • BASSic

Posted April 22, 2008 - 02:32 PM


I did the O ring mod a few weeks ago on my 01 426 and noticed that when I snap the throttle, the O ring stretches and it takes a few seconds for the accelerator pump linkage to catch up. I've heard the pump rod can get corroded or gummed up causing this slow movement.

How likely is it that the accelerator pump diaphragm is also worn? I don't see too many posts about them needing to be replaced.

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  • grayracer513

Posted April 22, 2008 - 03:06 PM


The only thing that can happen to the diaphragm is for it to tear or otherwise leak, in which case it would cause an external fuel leak, and the leak would speed up the linkage travel, not slow it down. If the discharge nozzle, or any other part of the AP circuit between there and the pump chamber is clogged, that will slow the pump rod up.

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