Mechanics

CHEVY WON'T START/RUN WITH MAF SENSOR PLUGGED I

2000 Chevrolet Blazer

Engine Performance problem
2000 Chevy Blazer 6 cyl Four Wheel Drive Automatic

2000 Chevy blazer is hard to start and will not stay running with the MAF sensor plugged in. If I un plug the MAF it will start and stay running. I can plug the sensor back in while it is running and it will stay running until I shut it off. Replaced fuel filter, checked all injectors, replaced fuel pressure regulator, checked fuel pressure at rail (60-63 drops 5 when running) swapped O2 sensors, replaced IAC, no DTC's, replaced MAF sensor.
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2KBlazer
March 21, 2009.



PCM POWER & GROUND CHECK Ground Circuits 1. Using an ohmmeter, check for continuity to ground at PCM ground terminals. See CONTROL MODULE CONNECTOR TERMINAL IDENTIFICATION . See Fig. 1 - Fig. 4 . Resistance should be zero ohms. If not, repair open to ground. 2. Using a voltmeter, connect negative lead of a voltmeter to a good ground. Backprobe positive lead of voltmeter to each ground terminal. With vehicle running, voltmeter should indicate less than one volt. If voltmeter reading is more than one volt, check for open, short to voltage, corrosion or loose connection on ground circuit. Power Circuits 1. Using a voltmeter, check for battery voltage between PCM continuous power terminal(s) and ground. See CONTROL MODULE CONNECTOR TERMINAL IDENTIFICATION . See Fig. 1 - Fig. 4 . If battery voltage is not present, check for open fuse or fusible link. If okay, check for open in wire between PCM terminal and power source. 2. Turn ignition switch to RUN position. Using a voltmeter, check for battery voltage between PCM ignition power terminals and ground. If battery voltage is not present, check IGN fuse. If fuse is okay, check for an open in wire between battery and ignition switch, and between ignition switch and PCM terminal. If wiring is okay, check for a defective ignition switch. 3. Connect voltmeter between ground and PCM starter (crank) signal terminal. On vehicles with manual transmission/transaxle, depress clutch pedal. On vehicles with automatic transmission/transaxle, position gear shift lever in Park. On all vehicles, turn ignition switch to START position. Battery voltage should be present ONLY when ignition switch is in START position. 4. If voltage is not present, check CRANK fuse or fusible link between ignition switch and PCM terminal. If fuse or fusible link is okay, check for an open in wire between ignition switch and PCM terminal, or check for a defective ignition switch. PCM Harness Resistance Turn ignition switch to LOCK position. Disconnect PCM and appropriate component harness connectors. Check for open or short circuits between appropriate PCM harness connector terminal and appropriate component harness connector terminal. See CONTROL MODULE CONNECTOR TERMINAL IDENTIFICATION . See Fig. 1 - Fig. 4 . See WIRING DIAGRAMS article. If harness is open or shorted, repair as necessary. NOTE: To identify circuits referenced in the following ground and power tests, see WIRING DIAGRAMS article. Page 1 of 1 SYSTEM & COMPONENT TESTING -2000 Chevrolet Blazer 3/22/2009


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Merlin2021
Mar 22, 2009.
That diagram does not match the connectors to my pcm. I can't find a diagram that does. The connections are labeled White Black Blue Red and the White, Blue, Red ones are labeled pins 1-32 and the black is 1-24.

Tiny
2KBlazer
Mar 22, 2009.
Please tell me what engine you have?

Merlin2021
Mar 24, 2009.
4.3l V6

Tiny
2KBlazer
Mar 24, 2009.
Check out Jakes video on youtube..
http://www.youtube.com/watch?v=eGpVXCJBMGM
I will look for your diagram, but the PCM connector should be pretty much the same...INTERMITTEN NO START OR HARD START WHETHER THE VAN IS COLD OR HOT. TRACE PROBLEM TO THE CONNECTOR BY THE FUEL TANK. WHEN YOU SEPARATE THE PLUG, YOU FIND THE PLASTIC MELTED CAUSING THE VAN TO NOT START

Merlin2021
Mar 25, 2009.