Thread: tuned engine one day the next its not

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I just got a new 350 with a good size cam from a friend, I had them swapped the motors tweak the timing
the carb got the truck running sweat. the next day started the truck and it did not want to idle
it was running rich so went threw the same process a day or to later it did the same thing
a friend said it acts like the carb is loading up so I went and bought a new carb set it up
and again a day later the same now its been 2-3 weeks of this B.S. can some one
PLEASE HELP

You're running an Edelbrock/Carter carb, right?

If so, your vacuum levels are low due to the big cam and the metering rods are opening before they should.
(Vacuum holds the rods down (lean) shut, the springs open them (richer).

Looking from here I'd say you're running too strong of a metering rod spring.
Try a pink one and see how that works.

Don't go too light on the springs or you'll get a flat spot when the secondaries come open.

When you adjusted everything was the engine warmed up. When you started it the next day were you able to warm it up by giving it some gas until it started to idle? How big of a cam do you have in it, that can sure impact the idle and warm up. If your running a holley make sure you check your vacuum at idle warmed up. You might then need to change your power valves based on your vacuum reading.

i am running a holley 600.

yes its warmed up to about 180 when we timed it and a just the the carb

now that is the temp but do i need to drive it for a 30 min. or so the get the cam a op. levels

as far as the cam size i will need to get the box back from my buddy i left at his house last time folled with it

Typically factory float levels are a little too high for here in AZ. Try adjusting the float level down a little bit and see what happens.

Also if your running an aftermarket high pressure fuel pump you may need to run a fuel pressure regulator to keep the pump from overwhelming the neddle and seat.

went down and replaced the carb to a 750. That helps the idle the last two days it ran good
so it might of been the metering rod spring.
it get it to run I had to advance the timing a lot. So I am thinking the distributor
might be a tooth of .
Thanks to every one that helped