Vacuum Pressure Testing
Wags391
12-04-2007, 11:26 PM
I would like to test my engine for vacuum pressure. I rented the tool. What can i do from there?
blazes9395
12-05-2007, 12:59 AM
I don't know if this is TBI engine or a CPI engine. Either way, locate a vacuum port and connect your guage there, start the truck up and watch the gauge and record your findings.
Wags391
12-05-2007, 06:12 PM
It is a TBI engine. 92 S10 Blazer, 4x4, 4.3L Z.
Vacuum findings:
Pressure at manifold intake: a steady 19.
What is the measurement name?
Any other tests I can do to make sure all vacuum is good?
Vacuum findings:
Pressure at manifold intake: a steady 19.
What is the measurement name?
Any other tests I can do to make sure all vacuum is good?
MT-2500
12-05-2007, 07:21 PM
19-20 range is good vacuum.
It is called inches of HG inches of vacuum.
Some gauges read in mm hg and some in g cm but I like it in of vacuum better.
Most vacuum gauges have a green range for good and a red range for bad.
lower vacuum inthe 15-17 range is late timing or a egr valve open or vacuum leak some place.
A flickering vacuum reding is a bad valve amd a engine miss will lower vacuum.
A good cat stopped test can be run with a vacuum gauge to .
check vacuum at idle and then at 2000 rpm.
If vacuum drops at 2000 under idle the exhaust system is restricted.
Also a vacuum gauge on the dash can help get better gas mileage.
Some older cars had one in dash for gas mileage improvement
Keep it in the green 19-20 range for good gas mileage.
I have had it bring gas milage up and over 5 MPG more.
MT
It is called inches of HG inches of vacuum.
Some gauges read in mm hg and some in g cm but I like it in of vacuum better.
Most vacuum gauges have a green range for good and a red range for bad.
lower vacuum inthe 15-17 range is late timing or a egr valve open or vacuum leak some place.
A flickering vacuum reding is a bad valve amd a engine miss will lower vacuum.
A good cat stopped test can be run with a vacuum gauge to .
check vacuum at idle and then at 2000 rpm.
If vacuum drops at 2000 under idle the exhaust system is restricted.
Also a vacuum gauge on the dash can help get better gas mileage.
Some older cars had one in dash for gas mileage improvement
Keep it in the green 19-20 range for good gas mileage.
I have had it bring gas milage up and over 5 MPG more.
MT
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