Author Topic: not wot from light  (Read 2647 times)

Offline 17058263

  • Garage guy
  • **
  • Posts: 36
not wot from light
« on: October 03, 2012, 03:54:27 PM »
Engine pontiac 400 stock auto trans drom a dead stop the 4bbl won't work from 55 mph it kicks right in . Carb 17058263 72 jets 44 custom rods cv seconday rods under no load the top doors will open right op helf way in park half turn n the spring tension.  And 2 second pull off

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5401
Re: not wot from light
« Reply #1 on: October 04, 2012, 05:34:51 AM »
The secondaries are mechanical, the air door opens based on demand.  If both parts are moving freely, it should be working fine from a dead stop, same as hitting it at 55mpg.

The big difference is that the engine has to pull thru into the good power, unless the tires go up in smoke, then transition is much faster.....Cliff

Offline 17058263

  • Garage guy
  • **
  • Posts: 36
Re: not wot from light
« Reply #2 on: October 04, 2012, 06:02:52 PM »
Should thevtop dorrs open if  just nail the throttle in park be cause they do. Half way , should I tighten the doors up some. And any thing over 70 the 4bbl will not kick in

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5401
Re: not wot from light
« Reply #3 on: October 05, 2012, 03:09:55 AM »
The release time of the choke pull-off is a key player here.

The linkage from the pull-off up to the flaps should be set to hold them tightly shut at idle (high vacuum), but allow them to fully open at zero vacuum (full throttle).

Many pull-offs are too slow, and hurt secondary performance.

I highly recommend getting one of our custom HP pull-offs for that carb number.  They release very quickly, but not so quickly they will induce a stumble/hesitation/bog.

I would also install a new secondary cam and spring, to insure full lift of the metering rods, and smooth action from the spring tension......Cliff