silvertripper

Okay, this might be easy for someone but for me its not. I have a Holley 600cfm 4160 carb on a rebuilt 350 motor. I can start cold and drive the car with no problems. But if I drive the car for a while, then turn it off, then crank it up again after 30 minutes or so of sitting there the motor kinda gags when I give it the gas. But after about 5 minutes its fine. This only happens after I start the already warmed up motor. Ive changed my power valve and that didnt help. I adjusted my rich/lean mix and this didnt help either. Ive also adjusted my timing. It almost seems like its getting to much gas after sitting there for a while after Ive already driven it. But if I waite until the car is cool to start it, its fine! This doesnt make any sense?

jg95z28

This is just a wild guess, but have you checked the fuel pump?

silvertripper

Fuel pump reads 7-8 psi. Mechanical and its 3 months old. What else could it be?

jg95z28

Manual choke or electric on the carb?

silvertripper

Electric Choke... and I've adjusted the choke to about a 10% choke when cool... to the point that I might as well take it off completely.

kacy

what about the bowls leaking and flooding the motor and after it sits for a long peroid it will start again

talos

I would, Theres no real need for them, thats what i did when i got my carb.... off with the choke...

u just have to keep ur rpms up a weeee bit when its warming up on a cold morning.

silvertripper

How can I tell if they are leaking?

Also, I forgot to mention that every now and then, when Im driving and I decelerate and then accelerate quickly (like going around a slow driver), it will caugh up..... acts like its gagging for a sec, and then its fine.

kacy

runs really rich close the a/f screws see if it dies or keeps running

Chads71camaro

It sounds like you have a possible percolation problem. What you might need is some kind of spacer between the carb and intake. After you shut the motor down all the heat in the intake and motor rises up into the carb and boils the fuel out of the bowls and then when you try to restart it you have a empty and very hot carb. And on the other problem I would try adjusting the floats.

silvertripper

Okay, I already have a spacer under the carb. But it does feel like its getting too much gas.... or not enough. Im going to try and adjust the air/fuel and see if it helps.

I'll have to check this in a few of weeks guys, my band is flying to Boston to record an album. I'll get this thread going again when... or if.... I return. Wish us luck!

kacy

good luck

silvertripper

okay, just got back about a week ago! I took some $$$$ and baught a 750 carb w/vacuum sec. This seemes to have solved my problems. I think I might have been starving my engine of gas. My car runs AWSOME now... the best it ever has run thanks to the carb swap. I guess this is let anyone know who might have had the same problems that I did with a small carb, maybe going to a larger carb will to the trick?