Page 1 of 2 12 LastLast
Results 1 to 10 of 19

Thread: 80457-12 1615 gas drip from secondary vacuum.

  1. #1
    Join Date
    Apr 2019
    Location
    NO, LA
    Posts
    15

    Default 80457-12 1615 gas drip from secondary vacuum.

    Hi guys! Newbie here. First post. I just purchased a '66 C10 with a 350. I have a small gas drip from the secondary vacuum while running. It does not drip if not running. What could be causing this and how do I fix it? Thanks in advance!
    Click image for larger version. 

Name:	Screenshot_20190411-223719_Gallery.jpg 
Views:	14 
Size:	98.8 KB 
ID:	8084
    Last edited by Frankwhoa; 04-11-2019 at 10:40 PM. Reason: Added picture

  2. #2
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,368

    Default

    First thing to do is check the float levels with the engine running. More than likely, secondary fuel bowl level is high, possibly a weeping needle & seat, or bad o-ring. Gary
    Regards, Gary

  3. #3
    Join Date
    Apr 2019
    Location
    NO, LA
    Posts
    15

    Default

    Turns out the rear vacuum port was open. I haven't noticed anymore fuel dripping since plugging it (no brake booster).

  4. #4
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,368

    Default

    Do you mean the drip was from the diaphragm stem, circled in your photo? Probably has a hole in the diaphragm. Your large vacuum hose at the back is perished at the fitting, and your electric choke is not grounded on the negative terminal. Gary
    Regards, Gary

  5. #5
    Join Date
    Apr 2019
    Location
    NO, LA
    Posts
    15

    Default

    Thanks Gary. She runs much better now. I appreciate your help.
    Last edited by Frankwhoa; 04-13-2019 at 07:37 PM.

  6. #6
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,368

    Default

    You're welcome Frank. Gary
    Regards, Gary

  7. #7
    Join Date
    Apr 2019
    Location
    NO, LA
    Posts
    15

    Default

    OK, I think the leak is fixed since I changed the diaphragm, but sometimes it goes back & forth between wanting to die and running good while in gear stopped. I checked both bowl levels and they are perfect. Other times it runs perfect. What should I look at next?

  8. #8
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,368

    Default

    I'd drop the secondary float level by one flat at a time, if you're having a stall condition while stopping. There's a lot of difference in opinions of float levels using the level plugs. Newer bowls with sight glasses are more accurate. Gary
    Regards, Gary

  9. #9
    Join Date
    Apr 2019
    Location
    NO, LA
    Posts
    15

    Default

    OK, what is one flat?

  10. #10
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,368

    Default

    You have adjustable needle & seats? Turn the nut down by one flat, the nut has six flats.
    I mark my adjusting nuts with a dab of red paint, that way I know where I was previously.
    Regards, Gary

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us