PINTO CAR CLUB of AMERICA

Shiny is Good! => Your Project => Topic started by: 72Wagon on June 26, 2012, 04:54:25 PM

Title: Holley 390 cfm 4bbl problem?
Post by: 72Wagon on June 26, 2012, 04:54:25 PM

 I am running a Holley 390 cfm carb, and the problem I am having is that the engine intake vacum is pulling fuel from the accelerator pump squirters at higher RPM's. and causing an erratic miss.  The engine has a a stout camshaft which is not helping. If any one can help me cure this problem I would be a very happy Pinto owner.

Title: Re: Holley 390 cfm 4bbl problem?
Post by: 71hotrodpinto on June 27, 2012, 02:10:43 PM

At one time i had the same problem on my exact setup. However its been so long i forgot if i ever solved this issue.
 The 2000cc and the 390 carb end up having a very high inlet velocity which cause this problem.
 
Look and see if there is a Ball or a pointed rod underneath the Acc pump nozzle.
You want the pointed rod. Apparently its heavier and less prone to letting fuel by.
 
This is also an idea.
an " Anti Pullover Nozzle ".
 
 
http://www.ebay.com/itm/Holley-121-231-Anti-Pullover-Nozzle-/200722057521 (http://www.ebay.com/itm/Holley-121-231-Anti-Pullover-Nozzle-/200722057521)
Good luck!
 
 
 

Title: Re: Holley 390 cfm 4bbl problem?
Post by: 72Wagon on June 27, 2012, 05:05:35 PM

Yes I did look and it has the ball with a brass weight on top of the ball, still getting pullover siphoning at higher rpms.  I site on the net said that the anti-siphoning nozzle helps but did not stop the siphoning on his 4cyl holley 2bbl set up.
 I am going to try adding a tiny spring since it will be an easy attempt, and if that does not work I had suggested a steel weight in place of the brass.