Holley pump cams

[ddpsnake]

Hi guys i am a my wits end with this 600 VS Holley.I have rebuilt many before and cant figure this out,when i just slowly open the throttle there is nothing from the nozzle,when i do open the throttle more there it is gas.the spring on the arm have been adjusted up and down,so i bought the pump cam kit hope it help,so what color cam has the quickest and fastest shot.Tried # 25 and 31 nozzles also.

 

[PurpleBeeper]

Don't get frustrated. You should have the spring on the arm adjusted so that there is no play at all with the carburetor in its idle position. If you've done that, try again. If it still doesn't squirt right away, the most likely the spring inside the accelerator pump isn't pushing the diaphragm up (down actually) all the way. You can stretch that spring or replace it.

To answer your question.... the fastest squirting is the one that has the steepest ramp up front. Don't forget that there is a #1 and a #2 cam position as well. good luck

Almost forgot... when you're inside the accelerator pump, take a look at the captured BB or the rubber diaphragm inside there on the bowl. If the BB is jammed or the diaphragm isn't sealing well, that would also cause the problem you describe.

 

[68 HEMI GTS]

Check the Condition of pump diaphragm or check valve under it.

 

[bm02tj]

Check ball not seating

 

[ddpsnake]

Well it was the check ball, now it responds great off idle,i put in the pink cam,but it hesitate half throttle now.but i am happy with it so far.Do you think # 31 nozzel would fix it,it has the #25 nozzel in.