Jump to content


Photo
- - - - -

Stumbling under acceleration


  • Please log in to reply
5 replies to this topic

#1 endofzworld

endofzworld

    Moving Up

  • Members
  • PipPip
  • 39 posts
  • LocationPooler GA

Posted 28 July 2016 - 08:39 AM

I had posted a topic under fuel delivery but didn't get a whole lot of answeres there.

Setup is an l28 w/ triple webers, holley red fuel pump, cheap regulator from the auto parts store.

If I mash the pedal it will cut out until I let off. I can go full throttle if I'm nice to it and and gradually step on it.

I had also posted this http://www.racetep.c...fuel-pumps.html

In short it says use a fuel pump with more volume, not pressure, don't run a Vacuum hose into the manifold (which I am) but I've seen people using the same pumps and not have theseen issues.

I bumped the psi from 4psi to about 6psi because it seemed to help a bit.

94 firebird formula

73 240z


#2 NewZed

NewZed

    Clandestine Moderator

  • Donating Members
  • PipPipPipPipPipPipPipPip
  • 5385 posts
  • LocationWashington County, Oregon

Posted 28 July 2016 - 08:58 AM

Sounds like an accelerator pump issue (not fuel pump).  It a device in the carb that squirts a bunch of extra gasoline in when you "mash" the pedal.  With a bad pump the engine gets extra air but not extra gasoline, and loses power as it leans out.

 

Not a Weber expert but that's what I'd confirm is working right first.  If the Weber's even use one.



#3 Leon

Leon

    Tremendous grasp of the obvious.

  • Donating Members
  • PipPipPipPipPipPipPip
  • 2318 posts
  • LocationSan Bruno, CA

Posted 28 July 2016 - 09:24 AM

Sounds like a tune issue, that pump should be plenty.



#4 endofzworld

endofzworld

    Moving Up

  • Members
  • PipPip
  • 39 posts
  • LocationPooler GA

Posted 28 July 2016 - 10:09 AM

Just wanted to see if anyone had a setup like the one in that article and if they found it more efficient.

Accelerator pump sounds like a good place to start thanks for the tip... I'll look into it

94 firebird formula

73 240z


#5 Samurai7one

Samurai7one

    Regular

  • Members
  • PipPipPip
  • 83 posts
  • LocationPearl River, Louisiana

Posted 28 July 2016 - 06:19 PM

Most of my experience is with the mikunis but I'll go ahead and try to throw some suggestions out there.

Put fuel pressure back down under 4psi.
Check linkage sync.
Check accelerator pump settings.
Check float levels, are they consistent? Can you raise the fuel level a bit.
Increase pilot jet size.

Got a sync tool? Got a color tune? AFR gauge?

#6 endofzworld

endofzworld

    Moving Up

  • Members
  • PipPip
  • 39 posts
  • LocationPooler GA

Posted 29 July 2016 - 05:22 AM

Don't have any of those. Our know I need to pick up an Afr Guage asap.

Does anyone know a good reference for float setting? Never really messed with it

94 firebird formula

73 240z





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users