How to set vacuum advance on older cars

Tuning how to set vacuum advance on older cars

[rockymini]

Best video on YouTube on vacuum advance and I’ve been searching forever. Thank you.

[Craignevis]

Just for clarity. The only difference between ported and manifold vacuum is that manifold vacuum gives you vacuum at idle and therefore, timing advance at idle. If you’re hooked to ported vacuum you will not have any vacuum at idle. Therefore you will have no timing advance at idle. Only when you begin to step on the throttle will vacuum come in and timing will begin to advance. So if you set your initial timing while hooked up to manifold vacuum and you want to switch to ported vacuum you will have to increase your initial timing because when you disconnect from manifold vacuum you’re taking away some advance timing the canister added at idle. If you’re driving a vehicle with a stock to mild cam I would suggest using ported vacuum advance. A more radical engine with a big cam will benefit from manifold vacuum advance.
There are lots of videos and articles on vacuum advance out there and most are very vague. Hope this helps.

[Repete]

Thanks for this. I have been fine adjusting the idle vacuum advance on my crate 350. And you just accidentally reminded me that my actual condition needs to be set while in gear. My car has an automatic transmission, with a pretty sturdy converter.

[nickrodriguez]

Thank you for your explanation. I enjoyed your explanation.

[Algorhythm]

Incredibly helpful video, thank you for recording it! When adjusting these canisters with an allen key, in your experience does the screw/adjustment "lock out" at some point (i.e it cannot be turned any further)? Like another commenter, no matter what allen key I use I'm either unable to get a bite on it or the screw/adjuster is just spinning in place.

[GJJC]

Great video. Very simple & quick. Do you remember what adjustable vacuum can is reliable (Brand / Part #)? I also read that if the can is not fully working this can affect your mpg? How so? Thanks

[paulthompson]

U forgot the No1 point . Vacuum advance occurs at light throttle steady state cruise ie between 27mph ---- 55mph . U set the xtra advance between these vacuum /road speed points .
If u still have a very basic distributor u may need xtra advance pending your setup so either manifold or ported setup might be better for you .
When u have standalone programmable timing idle timing and cruise advance can be what ever u want

[JoeVinson]

So, do you want it to be equal to the vacuum your engine is pulling at idle? Thank you for this video!

[thejodyg]

which way do you turn the wrench to lesson the amount of vacuum that it takes to advance the timing?

[butchking]

iv seen a lot of vids and out of all of them this is the best one i seen on how to set your adj vacuume canister very well explained

[nursecuenca]

My 350 chevy small block is hooked to only manifold vaccum. I tuned it to 12 degrees tdc. When I place vaccum gauge the best I could get to tune is at 14 gh vac. Any suggestions? And if I open timed vaccum from distributor will that increase that number?

[OG_DSM]

This is a great way to explain how this vac advance works. I purchased an 87 Starion that has Vac Ad and it has a misfire under wot. It pops and leans out on my af as my foot goes down. It was making over 18lbs of boost and suddenly, can't get past 5 or 6 without a band and pop. Could my vac ad be out of whack? Haven't changed the plugs nor the distributor yet.
I plan on checking the vac ad to see if it holds pressure... At idle, I feel no suction on that line and it goes right to the throttle body. Any suggestions would be great!

[kevinragsdale]

I cant figure out how to tune/set up the advance on my 300 i6, I stuck all size allens in there and couldnt find anything to bite.

[joeytacey]

The problem with having it hooked up to a manifold vacuum is that it pulls on the diaphragm all of the time thus shortening the life of the vacuum advance unit... If it was hooked to ported vacuum it would not pull 100% of the time.. just saying

[johnc]

I'm really curious I have my vacuum advance coming off my distributor on the side of my carburetor. Should I be hooked up to the manifold vacuum for this to work correctly

[maxmillion]

So, your vacuum @ idle was 12-14. YOU set your vacuum canister to 10?

[HonkeyLee]

This number 13 is that the amount of vacuum in drive or park?

[Skeksi_Man]

My 1977 Camaro (250 inline 6 automatic) has a dead spot / hesitation just off idle when I hit the gas pedal from stopped and when I hit the gas pedal from cruising.

I’ll hit the accelerator and it momentarily feels like it’s going to stall before the car springs into action and then it runs fine

Sometimes it causes the car to stall completely when I accelerate around a sharp corner or bend unless I coast it and accelerate gently.

Could the vacuum advance cause this ?

I’ve already had a carb rebuild, accelerator pump and new fuel pump.

[Mr.EeToMyself]

Where has this video been hiding. How to adjust vacuum advance advice.

[S_C_A_R_F_A_C_E]

So just for the record, the vacuum advance canister should be pulled in to the max at idle?