I did a search but did not see or missed this topic. 2 questions....



Just today, the car (57' bird with 312 Weber 4bbl) started to sputter a bit when I pressed down on gas. Idles smooth, get above 40mph and seems to run fine. Acts like it is missing a bit at about 1500 on the tach and 35mph. Nothing serious like backfiring..{previous problem which turned out to be bent push rods} but the car does lunge a bit.



Tank flushed, fuel filter clean, starts right up. Points at .015. Any ideas what might be causing this? Has to be something simple... Like the 2 cent washer in my last post



One other question if you don't mind...



The mechanic who put the Weber carb with with electric choke on may have hooked it up wrong. He has the wire to the choke running to the blue wire running off the resistor heading to the coil. I was told by a couple of people that it should be connected to the ignition wire coming to the resistor instead. Make sense what I am saying?



Appreciate your thoughts as the gremlins continue to baffle me.

1957 Thunderbird

312

The best way to wire the electric choke is with a dedicated hotwire from the ignition switch terminal that is "hot" with the key in the "run" position.Should not be powered with the key in the äccessories position.Also should have an inline fuse  just before the choke just in case there is problem and can also be pulled if you are working on the car with the key in the run position.If you power it from the wire feeding the risistor you will not get full voltage to the ignition.You might try unhooking the power wire at the choke cap now and make sure its not causing a problem with the ignition which is causing your other breakdown to happen.

  

Edelbrock carburetors have the Weber name on them.


Lawrenceville, GA

This manual ought to help figure out the choke ......

http://www.edelbrock.com/automotive_new/mc/carbs_acc/pdf/carb_owners_manual.pdf 

.......and yes a whole lot of carburetor designs are licensed from Weber.

 
 Steve Metzger       Tucson, Arizona

Rods,

Just a thought , but why not run your power wire( for the electric choke )from the hot side of your coil ???? Saves  running a wire all the way back to your ignition switch .It will only operate when you turn the key on . You can still put a inline fuse in  if you wish .Just a thought ???????????

Lon

yblocksdownunder

  Yea a Weber... I know not an original Holley but it sure is easier to adjust and more dependable (probably just started a holley war here..get it???)  OK...

I was thinking of hooking the wire up to the supply side.  Should be the same amt of juice.

On the stuttering portion.. I noticed it got progressivly worse throughout the day...

Rod

1957 Thunderbird

312

 

Thanks for the link.  I will review and see if that answers my 2nd question.  Should have thought to go there first....

1957 Thunderbird

312

The hot wire for the choke coil does need to be routed to a different source rather than being piggy backed on top of the ignition circuit.  Hooking the choke wiring to anywhere on the ignition circuit whether it’s at the resistor or the coil makes for a voltage drop to the coil and in turn creates the potential for the sputtering you mention.  As Mark mentions, simply unhook the choke wire temporarily while repositioning the choke coil so the choke is open all the time and see if this fixes the problem.

Lorena, Texas (South of Waco)

Ted,

It has been hooked up this way for some time without a problem but did short the wire when it touched the manifold some time back.  Replaced the wire and never thought anything else about it.  I guess it the coil etc. are getting old this could have an impact couldn't it?

Rod

1957 Thunderbird

312

Its been forever since I looked it up - is .015" OK for a single point gap? On a v8, that can't be a heck of a lot of dwell (time) to charge the coil. A low charge time and less than "stiff" electrical feed to the coil would make for a pretty anemic spark.

 
 Steve Metzger       Tucson, Arizona