Pontiac Fiero 1988 Service Manual page 530

D R I V E A B I L I T Y
AND EMISSIONS -
FUEL
INJECTION (TBI) 6E2-C1-13
CHART C-1D
MAP OUTPUT CHECK
2.5L SERIES (TBI)
©
• I G N I T I O N " O N " , ENGINE STOPPED.
" S C A N " TOOL SHOULD INDICATE A VOLTAGE WITHIN
THE VALUES SHOWN IN THE CHART BELOW.
OK
NOT OK
©
• DISCONNECT VACUUM HOSE AT MAP
SENSOR AND PLUG HOSE
© CONNECT A HAND VACUUM PUMP TO
MAP SENSOR
• START ENGINE
• APPLY 34 kPa (10") OF VACUUM AND
NOTE VOLTAGE CHANGE. (VOLTAGE
SHOULD BE 1.2 - 2.3 VOLTS LESS THAN
STEP 1.)
REPLACE SENSOR
OK NOT OK
©
NO TROUBLE FOUND. CHECK MAP
HOSE FOR LEAKAGE OR
RESTRICTION. BE SURE THIS HOSE
SUPPLIES VACUUM TO MAP SENSOR
ONLY.
REPLACE SENSOR
ALTITUDE VOLTAGE RANGE
Meters Feet
Below 305
Below 1,000
3 . 8 -
-5.5V
305—610 1,000-2,000 3.6- -5.3V
610— 914 2,000-3,000 3 . 5 - -5.1V
914--1219 3,000-4,000 3 . 3 - -5.0V
1219--1524 4,000-5,000 3 . 2 - -4.8V
1524-1829 5,000-6,000 3.0- -4.6V
1829-2133 6,000-7,000 2.9™ -4.5V
2133-2438 7,000-8,000 2 . 8 - -4.3V
2438-2743 8,000-9,000 2.6- -4.2V
2743-3048 9,000-10,000 2 . 5 - -4.0V
LOW
ALTITUDE = HIGH PRESSURE = HIGH VOLTAGE
CLEAR C O D E S AND CONFIRM " C L O S E D L O O P " OPERATION AND NO "SERVICE ENGINE S O O N " LIGHT.