ENGINE DIAGNOSTIC TEST PROCEDURES
Section 6
•
INTAKE MANIFOLD PRESSURE
- 400 Series On-Highway Engines
(with Robert Bosch MW Pumps)
FROM FORM NO. CGED-365
INTAKE MANIFOLD PRESSURE*
10
A.
MEASURE AT FULL LOAD AND AT SPECIFIED SPEEDS.
B.
SELECT TRANSMISSION GEAR TO ACHIEVE FULL LOAD.
(AUTOMATIC TRANSMISSION - STALL RPM & LOAD).
INSTRUMENT
GUIDELINE DATA‚
1st CHECK
2nd CHECK
PRESSURE GAUGE
(30 PSI RANGE)
*Engine must be at normal operating temperature.
p Refer to "Performance Data Guidelines", in this Section.
1.
Check intake manifold pressure as follows:
a.
DT and DTI: Remove the 1/4 in. NPT pipe
plug from the air discharge pipe and install a
connector and plastic tubing (Figures 23a and
b).
b.
Connect the other end of the tubing to the
pressure gauge kit panel (SE-2239).
c.
Operate the engine under load until the engine
reaches normal operating temperature.
Measure intake manifold pressure at full load
and rated speed and at full load and the
specified
lower
speed.
Refer
to
the
"PERFORMANCE DATA GUIDELINES" at the
end of this section.
d.
Enter the observed manifold pressure in the 1st
check box. If intake manifold pressure is within
the
specifications
shown
in
the
PERFORMANCE DATA GUIDELINES, engine
power is acceptable.
CGES-240-4
Printed in United States of America
Page 30
