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How to do vacuum pressure test?

  • Thread starter Thread starter mob
  • Start date Start date Mar 2, 2009

mob

the guy who hits on his mom
20+ Year Stangneter
Oct 3, 2003
2,566
136
104
Dallas, TX
Mar 2, 2009
#1
  • Mar 2, 2009
  • #1
Hey guys, after installing my fuel pump my car is running like it has a vacuum leak. Brakes are alittle stiff and the rpms go up when I let off the gas or get out of gear. It also has a small small surge. Im guessing I just hook the gauge up in between a vacuum line. Any recomended line to put in between? And what kind of numbers am I looking for.

And also on the fuel tank is that a vacuum line on the top of the fuel tank? Im not sure if it stayed alittle loose when I put the tank back in. If that is a vacuum line will that come up when I do the vacuum test?
 

1991vert

10 Year Member
Feb 27, 2004
1,103
7
69
Ludlow, MA
Mar 2, 2009
#2
  • Mar 2, 2009
  • #2
mob said:
Hey guys, after installing my fuel pump my car is running like it has a vacuum leak. Brakes are alittle stiff and the rpms go up when I let off the gas or get out of gear. It also has a small small surge. Im guessing I just hook the gauge up in between a vacuum line. Any recomended line to put in between? And what kind of numbers am I looking for.

And also on the fuel tank is that a vacuum line on the top of the fuel tank? Im not sure if it stayed alittle loose when I put the tank back in. If that is a vacuum line will that come up when I do the vacuum test?
Click to expand...

that's called the vapor valve aka gas tank vent. it goes to your charcoal canister and it will create a vacuum leak. if you did not allow your gas tank to vent it would crush itself from all the vacuum. just double check all the vacuum lines

edit: i think i used my fuel pressure regulator vacuum source when i checked mine
 

mob

the guy who hits on his mom
20+ Year Stangneter
Oct 3, 2003
2,566
136
104
Dallas, TX
Mar 3, 2009
#3
  • Mar 3, 2009
  • #3
Ok thank you, Im hoping its not my intake gasket, I just replaced it, I am getting some bubbles in my radiator, having alot of over heating problems.

Any ideas what numbers I should be looking for on the vacuum test?
 

1991vert

10 Year Member
Feb 27, 2004
1,103
7
69
Ludlow, MA
Mar 3, 2009
#4
  • Mar 3, 2009
  • #4
mob said:
Ok thank you, Im hoping its not my intake gasket, I just replaced it, I am getting some bubbles in my radiator, having alot of over heating problems.

Any ideas what numbers I should be looking for on the vacuum test?
Click to expand...

what cam?
 

mob

the guy who hits on his mom
20+ Year Stangneter
Oct 3, 2003
2,566
136
104
Dallas, TX
Mar 3, 2009
#5
  • Mar 3, 2009
  • #5
B cam, I just find the vacuum at idle right?
 

1991vert

10 Year Member
Feb 27, 2004
1,103
7
69
Ludlow, MA
Mar 3, 2009
#6
  • Mar 3, 2009
  • #6
correct. i wanna say a lot are between 12-15 at idle
 

mob

the guy who hits on his mom
20+ Year Stangneter
Oct 3, 2003
2,566
136
104
Dallas, TX
Mar 3, 2009
#7
  • Mar 3, 2009
  • #7
Im at 12 in HG on the gauge, or 30 cm HG is that low?

EDIT: just saw your post, thats weird, cause I started up my car and it wouldnt idle for about 5 minutes, it would just shut off I had to give it gas till it warmed up a little, and it was surging for a little bit. then it even out.
 
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