throttle response

[85general]

anyone who knows how to improve throttle response do reply !! 2.8 with duraspark an holley 350 #58 jets, response is snappy goin up an slow comin down.

 

[skippy]

anyone who knows how to improve throttle response do reply !! 2.8 with duraspark an holley 350 #58 jets, response is snappy goin up an slow comin down.

Get your vacuum up a little higher than 14 or 15".Try advancing the timing,readjusting idle richness screws.I believe you should be able to
get 18",I suspect the power valve is staying open to long.

Remember,power valve opens at half your vacuum at wot and may not be closing fast enough.If you are unable to get the vacuum up,you're going to
need a 75 power valve @14 or 15".

 

[85general]

ok went an got a better vacuum gauge an if it idles at 1300-1400 is a very steady 16 on the vacuum if it idles at about 1100 its 13-14 vacuum so lets say 15 vacuum i should get the 75 power valve? what do they come with stock?

 

[skippy]

ok went an got a better vacuum gauge an if it idles at 1300-1400 is a very steady 16 on the vacuum if it idles at about 1100 its 13-14 vacuum so lets say 15 vacuum i should get the 75 power valve? what do they come with stock?

#85 power valve.Try the return spring first,might save you some cash.

http://www.mortec.com/carbtip1.htm

 

[85general]

#85? and the return spring i already had on there iv tried a bunch of different ones my pedal gets stiffer thats about the only change still acts the same. so if my vacuum at idle is around 14-15 (it can go higher but i really dont like the higher idle) then wouldnt that be the #75 valve? take idle vacuum reading an divide by 2 right?

 

[85general]

oh gotcha read wrong, sorry

 

[trents]

I have a question about your idle speed. Why are you idling at 1100+ rpm? Stock is about 800. Can you kill the engine by turning your idle mixture jets all the way in? If not, the carb needs rebuilding and that could explain your problems with slow return to idle.

 

[85general]

yea if you turn em in to far it dies, i got it all worked out with some timing adjustments, mixture adjustments with the vacuum gauge, just dies when i hit the brakes? thinkin bout throwin the #61 jets back in it has 58's in it now an it just started dieing when i got it running decent

 

[trents]

I wouldn't think changing the main jets would have any effect on the dying problem when you let off the gas. Once you let off the gas you take take the main jets out of the equation. That's an idle circuit issue or vacuum leak, sounds like to me. Is this a new carb or a used one? What's your vacuum reading now and at what idle rpm? Should be 16 inches or better at 800 rpm unless you have a radical cam in it or bad valves. Mine runs 18-20 inches with a stage 1 RV cam which has a little longer duration than the stock cam.