sputter at high rpm

[dieselman123]

Hey guys I need your help I have a 355 sbc with vortec heads, comp cam 12-235-2  hydraulic flat tappet. Valve adjustment is spot on my timing is 14  btc  mechanical is 32 all in by 3200. I have my vacuum advance hooked up on manifold vac. Edelbrock 1406 carb. When I connect my vacuum advance my timing is 34 btc at idle. Fuel pressure gage shows 8 and I have it hooked up before filter. My problem is that under hard acceleration it falls flat on its face when I go wot while cruising. But from idle the motor is a monster. It's like I don't have any power at wot while cruising. Could it be too much total timing causing this. Also it might be a fuel pressure problem because while the engine is running the fuel filter goes dry and then pumps and it does it over and over again. Is this normal please help. Carb floats are in spec and dizzy is brand new

[roger97338]

If everything you say is correct, maybe your fuel pressure is fine, but your fuel volume is inadequate?

I'll let someone more knowledgeable about timing than I am answer that part of your question.

[blazer74]

You could plumb in a pressure gauge and see what the pressure is when this happens.

Timings not extreme.

Could be restriction in fuel supply from the tank and or a restricted sock in the tank.


Sent from my iPhone using Tapatalk

[timthescarrd]

the edelbrock 1406 doesn't like a lot of fuel pressure, max recommended at idle is 6psi, suggested 5.5 at idle, and should drop down to at lowest 2psi at full throttle. I have a see-thru glass filter, with a new fuel pump, it stays full all the time.  When i had an old pump that wasn't working great, it would fill and drain, fill and drain like you're describing at idle, and the fuel pressure would bounce from 1-5psi

[dieselman123]

Yea clear glass filter fills up and drains also before it fills back up. I will try to replace the pump . I do know the sock in the tank is the same age as the truck  maybe I need to get one of those. Any suggestions about the timing

[jg1977c20]

fuel filter going dry is not normal - you have a fuel volume issue maybe even a plugged tank vent are you using an electric or mechanical fuel pump ? and is it a stock mechanical pump if thats the case ?