Motor stalling on 87 vert
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St. Jude Donor '07-'08-'09-'10-'11-'12-'13-'14-'15-'16-‘17, '22
Motor stalling on 87 vert
Just thought I'd enquire if anyone here can point me in the right direction as I'm not familiar with MAF cars.
I'm posting on behalf of a friend with an 87. He has a problem with the car stalling almost immediately after startup.
If he unplugs the MAF sensor, the car idles fine. We have tried another MAF sensor and it still stalls when trialling the other one.
Any ideas on where we should be looking in the first instance?
I'm posting on behalf of a friend with an 87. He has a problem with the car stalling almost immediately after startup.
If he unplugs the MAF sensor, the car idles fine. We have tried another MAF sensor and it still stalls when trialling the other one.
Any ideas on where we should be looking in the first instance?
Advanced
Joined: Sep 2002
Posts: 60
Likes: 1
From: Syracuse NY
Re:Motor stalling on 87 vert
Replace both of the Mass Air Flow relays located on the firewall just above the battery. This will resolve the stalling issue. Below is the GM service bulletin that describes the problem.
Joe
Condition:
On the 1987 - 89 Y Car, the engine may have intermittent no start, long crank times, may start and stall after start, or may have engine surge or rough running. No codes will be set, and no trouble can be found using normal diagnostic procedures.
Cause:
The relay used for production, P/N 14103304, may not conduct enough current to allow the Mass Air Flow (MAF) circuits to operate properly. The relays will test OK.
Correction:
Both the MAF relays (Burn-off and Burn-off control) should be replaced with relay P/N 14089936. This relay is serviced with a bracket, which is used only for 1988, and can be discarded for the 1989 model year.
Part is currently available from GMSPO.
The 02 sensor may also be carbon-coated because of this condition. To clear the carbon, apply the parking brake, and allow the engine to warm up to normal operating temperature. Then hold the RPM at 1800 RPM for three minutes.
Joe
Condition:
On the 1987 - 89 Y Car, the engine may have intermittent no start, long crank times, may start and stall after start, or may have engine surge or rough running. No codes will be set, and no trouble can be found using normal diagnostic procedures.
Cause:
The relay used for production, P/N 14103304, may not conduct enough current to allow the Mass Air Flow (MAF) circuits to operate properly. The relays will test OK.
Correction:
Both the MAF relays (Burn-off and Burn-off control) should be replaced with relay P/N 14089936. This relay is serviced with a bracket, which is used only for 1988, and can be discarded for the 1989 model year.
Part is currently available from GMSPO.
The 02 sensor may also be carbon-coated because of this condition. To clear the carbon, apply the parking brake, and allow the engine to warm up to normal operating temperature. Then hold the RPM at 1800 RPM for three minutes.
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
That's interesting about the 02 sensor-good post. One thing I'd like to add-from the FSM, "The oil pressure switch or the ECM, through control of the fuel pump relay, will provide 12 volts for the MAF power relay which provides the 12 volts needed by the MAF sensor".
Go ahead and replace the relays mentioned-if that doesn't fix the problem-replace the FP relay.And while your at it, check the wires going into the fp relay, the insulations shrinks and bare wires can and do come into contact with one another, ask me how I know.
Go ahead and replace the relays mentioned-if that doesn't fix the problem-replace the FP relay.And while your at it, check the wires going into the fp relay, the insulations shrinks and bare wires can and do come into contact with one another, ask me how I know.
