[dlofc]

just like the title says how do you check the vaccum advance. it is a 1974 2.8liter and i just had to replace the points...sooo i went and replaced the condensor button and cap. but now i have a bad miss in upper rpms no backfires no ping. so i have been reading that the vaccum advance can cause this. also would like any advice on anything else that could cause it...but i do believe it is with something in the ignition system.

[heavy metal]

Use a timing light,engine running with light pointed at timing marks,vac hose on advance.Rev engine and you should see the timing advance.

[dlofc]

"DOOHHH!!!" i should have thought about that.....feel stupid after that but hey you live and ya learn

[heavy metal]

It is okay,we all have our moments.....

[dlofc]

well finally found the problem...my carb is not pulling any vaccum...sooo of course the vaccum advance couldnt advance the timming simple enough to fix ohhh and for some reason the diaphram on the egr and since there is no emissions where i live i disconnected it but it runs like a top again