Hesitation on acceleration

[SilveradoDude]

(85 Silverado)

I am getting severe hesitation on acceleration. I have tried the following.

- Rebuilt carb
- Increased the timing
- Checked for vacuum leaks (None)

Symptoms include, when I give it some gas I will get nothing until I jam on the gas or sometimes I can finesse the accelerator to get it to give me gas. At this point I am at a loss.

[geezer#99]

Could be the dreaded ‘flat’ cam.
Or hopefully just a bad plug or plug wire.

[my86lb]

have u checked the magnetic pick up coil in the distributor.

h.e.i-distributor-troubleshooting-with-performance-distributors

[Dariusld]

Originally Posted by geezer#99

Or hopefully just a bad plug or plug wire.

My guess.

[cadillac_al]

It sounds like the dreaded flat spot. When my Dad traded his 76 GMC C10/C15 (?) in on a brand new 84 GMC C10 we realized what a big step down it was right away. The 84 had the mother of all flat spots. You couldn't pass another vehicle because it would hesitate so darn long. The dealer couldn't figure it out so we just lived with it until he traded it for an 89 GMC. I guess GM was trying to get us to save gas lol.

This was before I was an engine tuner and this computer stuff was all new for the dealers too. I would probably try to make it work if I had one nowadays. New plugs and wires and tinker with slowing the secondary opening and let the primaries do their thing. If that didn't work then I would ditch the feedback carb and computer distributor and tune it like an older vehicle.