Animated Engine Vacuum Diagnostics

[Guest]

[MattMans88]

To Joel:  Thank you again for a very trick tech post, your the man!

To the new guys:    This is why this forum kicks ass lol

                           
                                                                                        -Matt

[teyerdhal]

I have just discovered this vaccum tech post, very useful!
Reading vacumm gauge become easy 

[aussiewinza]

ha,very cool, thanks

[Cold Aussie]

Woody
Why?

Stephen

[bluebloodracing]

Joel this was exactly what i was looking for.  
how about this reading?http://s1224.photobucket.com/albums/ee363/skipstjohn/?action=view&current=VIDEO0005.mp4 late 90's roller 302 with e303 1.6 roller rockers, just installed. Also, edelbrock rpm heads(190/160), and victor jr intake just installed(i know they vic is killing bottom end). It seems by my comparison, my timing may be a bit retarded? However, with the vacc canister on the (stock 85 gt dist) i cannot advance any further without moving a tooth. i think it runs too good to be off a tooth.??
all in all it seems to have picked up some power even with the "top end intake" its just not idling or, accelerating as smooth as before parts swap.

[Joel5.0]

Initial timing is set at ???? Did you recalibrate carburetor idle mixture screws? LUK

[juiced coupe]

It seems by my comparison, my timing may be a bit retarded? However, with the vacc canister on the (stock 85 gt dist) i cannot advance any further without moving a tooth. i think it runs too good to be off a tooth.??

Just FYI, my 85 GT distributor came with a L19 advance plate and two heavy springs in it. That's 38° of mechanical advance with a curve that's slow as Christmas. If you haven't already, open it up to see what you've got in there.

[bluebloodracing]

Joel, have not put a light on it yet, but i will let you know. i just brought #1 up on compression and pointed rotor @ it fired right up. I then moved it by ear. Yes, i did re calibrate idle mixture screws
 
Juiced, I will look at that tomorrow and let you know. i have a billet msd i want to use, but it had iron gear and im not sure how to change it.  i do know with current dist it will ping if i tromp it. now and before parts swap timing was set right with light b4 cant remeber #'s though. it seems this dist is letting timing move too much, even without vaccum hooked to it

Thanks guys, yall are the best..

[bluebloodracing]

initial timing was @ 13 degrees at that vac reading. I did put a kit in the carb it runs better, but still doesn't idle as smooth as it did.
I did not look at dist Juiced, i just ordered a msd with steel gear

[68mustang405]

I have less than that vacuum with a tfs1. I think that looks fairly well. You could keep advancing it till it stops increasing vacuum, or until you can't start it at idle. Then that would be your initial timing. Then you'd have to recurve your distributor to have less total timing.

[bluebloodracing]

yes, thats kinda what i figured. Thanks for the info