I just picked up a 77 vette about a week ago. It is a 350, with a drawthrough carb turbo system, and an automatic. I can't tell if there has been a cam swap, but at idle, my vac gauge reads 20. Sometimes though, it will go down to 13 after i slow down to a stop. When I get on the brakes even a little more firmly than usual, it seems like the engine just sputters and dies. Any suggestions for what the problem may be? Do I need a vac reservoir? (space is a little tight) Thanks

 

Try to run a more rich idle mix.

 

Does it do it only when braking, or will hard cornering tend to drop idle way down too? The reason I ask is cause I had sort of a similar problem with my '84 Camaro. Seemed like adjusting the carb floats fixed most of it. Of course, this is a complete shot in the dark.

 

Does it do it only when braking, or will hard cornering tend to drop idle way down too? The reason I ask is cause I had sort of a similar problem with my '84 Camaro. Seemed like adjusting the carb floats fixed most of it. Of course, this is a complete shot in the dark.

 

Will it try to stall if you are just sitting in park and you apply the brakes hard??

If so, check your booster/checkvalve.



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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R
and 2 POS commuters...

R.I.P. #3
"He can see air"

 

After doing some more testing with the brakes, and looking at the vacuum readings, I believe it may actually be the float levels on the carb that are messing things up. Thanks for the suggestions everybody!!

 

Sounds to me like the booster is defective...

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"So many Mustangs, so little time..."
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