C10 Cheyenne Tune

[Garifini1]

Can anyone point me to a good write up on a good tuning procedure? I have a 350cu. 5.7 liter in my 78 Cheyenne with an edelbrock 650, and of course HEI distributor.   I have been a EFI. Coil  guy up until this guy. I have tuning procedures for the Carb, and some for timing adjustment for the Distributor, and various posts on setting the Basic Timing, centrifugal, and total timing. As if I wasn't in for a meltdown I begin reading about Port Vacuum Vs. Manifold, and that I will run cooler, smoother idle, and better mpg if I go Full time vacuum.

The truck is dieseling a bit on shutdown, idle is good, but part acceleration could be a bit more responsive, and I notice MPG is worse than what I should be getting after much research.

What I want to know is the best system for an overall tune, begin with _____, until you reach____, then move to ____, adjust to ____ . you get the idea. I think I should be dialing in one thing at a time, and not bouncing all over components. I know this rig can run much better. I am information overloading and need to keep it simple...(stupid).

Thanks All
-Gary

[Captkaos]

If it is dieselling it is your timing.  I would set base timing to 8 degrees with the vacuum advance unplugged and get the idle to about 600 rpms
From there get a Vacuum gauge and adjust the carb idle and mixture screws to yield the highest vacuum reading.

[Garifini1]

Sounds like a good place to start, for the 8 degrees, I am guessing I will need to pick up a timing light, or check the crank pulley mark after pulling #1 plug and getting it to TDC? hope its not a ridiculous question.


I do have a vacuum gauge, and can go from there.

[FlatBlack77]

when you unplug the vacuum advance, you will need to plug the line.

and yes you will need a timing light. no need to go all in and get one of those super expensive ones. just a basic one will do.

hopefully the harmonic balancer  on your engine has a timing mark. alot of aftermarket ones from advance, auto zone, ect. do not have the mark.