Fine tuning the carb, still a bit of annoying hesitation... + tranny fluid quest

[russg]

First off, the car is in the shop getting the new Dynamic 11" torque converter installed which I'm excited about  I read through some posts and decided to have them put Ford type F tranny fluid in the old auto 727.  Did I do the right thing?

Carb issue: Holley Street Avenger 670 vac secondary.  Plugs seem to look good now and once under way runs very well.  When slowing down to a stop the car will start sputtering momentarily and if you were to punch it at this time it would do a small backfire and stall, you have to make small stabs at the pedal until it catches up then all is well.  If you take off from a stop you need to again with foot on brake make a couple small stabs at the pedal and feather it just past the hiccup and all is well.  Sometimes if you are able to sit still for a moment, as in coming to a stop and sit long enough for the little bit of stumbling to go away like it's catching up, it will take off with no problems.  There is absolutly no problems while under way, just down near idle speed, even more noticable while cold of course.

FYI, when I first got the car the carb had a rivet in the secondary lever like they were trying to make a mechanical secondary out of it.  I removed it along with the brass pulling arm that connects it to the front butterflies as it was all bent out of shape, I assumed with a vac secondary, that arm is not needed, am i correct? 

[R2]

This might help with the "stumble" issues at take off......

QUESTION My vehicle has a stumble from a dead stop. What can I do to cure this?
ANSWER The most common cause of a stumble is not having an adequate accelerator pump shot. The first thing to do is to look at the discharge nozzle and make sure you are getting a good strong pump shot. If not then you need to inspect the pump diaphram for a hole or tear. You will also need to make sure that the pump passage is clear from any trash or debris. First you will need to check the adjustment on the pump. To do this you will open the throttle all the way (WOT). Push the pump arm lever down and then adjust the pump override spring to obtain .015" clearance between the pump arm and lever. If you are having a stumble and no black smoke out the tailpipe then you will need to increase the shooter size. If it stumbles and you are getting black smoke from the tailpipe then it will be nessasary to decrease the shooter size.


I adjusted my pump and squirters and pump cam,,,till i got it dialed in...trial and error.........

I also run "jet extensions" to keep the jets from being "uncovered" during hard acceration and decelaration........

Hope this helps.......

ps,,,I run ATF +4 in my trans .....

DOUG

[R2]

ps,,,,

Russ,,,,what did you have previously for a convertor ?
sounds like you are doing a upgrade,,,? should be fun to drive........ 

Doug

[russg]

Replacing what I'm quite sure is the stock converter for a mildly higher stall unit so when you punch it it goes closer to were the power band is and and lower speeds supposedly drives like normal, can't wait to test it out because the 383 is a bit of a dog from 1,500-2,200 rpm  but gains steam quite quickly after that.  I rebuilt the carb just a few months ago so the diaphram in the accel pump should be good, it gives a decent squirt, might have to go from the current size 38 to maybe a 40 and see what happens.