Ok, now that GF's baby car has gotten a new accel pump diaphragm, shutter valve, and gas cap it is all happy and humms happily. Now, what made the big difference. I had previously disconnected and plugged the vacuum lines to the shutter valve as a temporary fix until the new unit arrived and could be installed. Therefore no vacuum leak was eliminated by replacing the shutter valve. The accel pump diaphragm leaked onto the old shutter valve, perhaps hastening it's demise so it was replaced at the same time. The old diaphragm was cracked but not torn and did in fact still squirt gas when the throttle was opened. The old gas cap had no rubber ring left and did nothing whatsoever to seal the tank. What do you guys think contributed the most to her car's happiness?

 

is this a multiple choice question? I say: a. the accel pump

 

Off-topic, but I wanna know... How much was it to fix the accel pump?

 

I'm going with accelerator pump.

 

The accel pump seems to be the popular choice. However, the idle smoothed out and overall power was better, not just throttle response when accelerating. I think my girfriend said the diapgragm was like $16 from mazdatrix, which struck me as steep. She ordered all the parts I told her to get and I installed them for her. It should be really easy to replace, except one of the screws is covered by the pivot pin and you cant get at it without pulling the pin out, requiring removal of the tiny jesus clip holding it in. There are two little washers that will drop when it is removed. I didn't remove the carb to do this, just disconnected everything except the nest of cables going to it. That gave me enough room to get at the accel pump and also to replace the shutter valve. Patience required here and definately cover the manifold with a rag to catch little parts.