carb automatic 89.

[shadetree]

I put together a carb auto car and I'm having some problems with it that I can't figure out ,so I'm asking for ideas on what it might be ....
It starts hard when cold . Kinda normal I know ,after a five minute warm up it will take another five minutes before it will shift out of first . Then it shifts great every time .
The main problem is after warm up and all that's done, when you try to take off from a stop and ease into the gas it will shut off ,but starts rite back up fine .
If you press down hard like half throttle its fine ,takes off great . It's like anything less then 1/4 throttle it shuts off .
It's not a mis then shut off its dead done that's it . Like a switch .
History
This is a four speed to auto swap
235,000 miles. Smokes , not bad .
New plugs ,wires ,cap ,button ,plugs ,gas filter , air cleaner ,complete tune up .
Car ran fine when it was a four speed .

Being so there is no actual line for the trans I connected into a large Vac line . I'm thinking the engine is just worn and not holding the Vac in needs but I thought I would ask around and see what you guys thought .
And yes the kick down switch has been installed on the gas peddle .
Thanks for info and ideas ..

[georgeb]

Don't know much about this swap except that the vac needs to be straight from the manifold like the brake booster vs. from the carb or air cleaner.

[FestYboy]

and you need to run more timing and have a higher idle speed than a normal carb should.

[shadetree]

Those were my thoughts as well . I will be adjusting and tinkering with this some .
It's really strange how the car idles and returns to idle after rev, just perfect . Never shuts off idling .