Bought a vacuum pump to diagnose...
Thread Starter
Drifting
Joined: Sep 2001
Posts: 1,427
Likes: 1
From: Boxford Mass
Bought a vacuum pump to diagnose...
all my vacuum problems. I got a decent deal on EBay. This little pump pulls 20 inches and has a gauge & regulator. $40.
I tapped it into the hose off the manifold and now I can diagnose without the engine running, which is important cuz I'm slowwwww.
Here's what I found by isolating things...
-- my vac cannister will hold 10in, no more.
-- my headlights are fine, tested them up to 20 and it held.
-- my wiper actuator relay leaks, holds 6.
So I figure that my engine is pulling close to 20in at idle. All these little leaks must be having some impact. I'm trying to decide whether to bypass the cannister or pull it out and tig weld it. That sucker looks pretty baked in there.
This was a great investment for **** people, like myself
, who feel obliged to test every part of their vacuum system. Fortunately, everything behind the dash held vacuum just fine. Phew.
I tapped it into the hose off the manifold and now I can diagnose without the engine running, which is important cuz I'm slowwwww.
Here's what I found by isolating things...
-- my vac cannister will hold 10in, no more.
-- my headlights are fine, tested them up to 20 and it held.
-- my wiper actuator relay leaks, holds 6.
So I figure that my engine is pulling close to 20in at idle. All these little leaks must be having some impact. I'm trying to decide whether to bypass the cannister or pull it out and tig weld it. That sucker looks pretty baked in there.
This was a great investment for **** people, like myself
, who feel obliged to test every part of their vacuum system. Fortunately, everything behind the dash held vacuum just fine. Phew.
Senior Member since 1492
Joined: Aug 2000
Posts: 87,953
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From: Just because I'm paranoid doesn't mean people aren't out to get me...
St. Jude Donor '09
Originally Posted by Jack71
This was a great investment for **** people, like myself , who feel obliged to test every part of their vacuum system. Fortunately, everything behind the dash held vacuum just fine. Phew.
, who feel obliged to test every part of their vacuum system. Fortunately, everything behind the dash held vacuum just fine. Phew.You sound a little disappointed.
I bought a Mighty Vac or Mini-vac or somthing like that years ago. I used it a couple times to bleed a caliper or two. Have graduated to a Pressure Bleeder.
One day I'll use the Mighty Vac to find out what's going on with my wiper door.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
do big blocks pull more vacuum then small blocks?????? 20" would be alot for a small block especially if there was any sort of cam in it.
Advanced
Joined: Jun 2004
Posts: 96
Likes: 0
From: Novelty OH
mityvac rules
Yes I've used my mityvac for a whole lot of diagnosis! most useful thing I've done with it is tuning in my vacuum advance canister. Hold the rpm at say, 1000. Pull vacuum on the advance canister and reset rpm to 1000 as you go. Write it down if you're me because you forget in about 2 seconds flat... I was able to get my advance right where I wanted it (16 degrees of vacuum advance)
I also pulled all of my non-essential vacuum lines and drove it... it did make a difference meaning that I had leaks... started replacing all my lines etc. and things have been steadily improving for me.
Good luck! It's an essential item in my garage.
FYI i can pull 20-21" at idle.. stock 1977 L48
I also pulled all of my non-essential vacuum lines and drove it... it did make a difference meaning that I had leaks... started replacing all my lines etc. and things have been steadily improving for me.
Good luck! It's an essential item in my garage.
FYI i can pull 20-21" at idle.. stock 1977 L48
