car quits like you shut the key off
- Thread starter 88vette
- Start date
try to pull trouble codes!
having the correct shop manual helps a great deal, but common sense (logic) in testing and tracking down electrical problems is a skill worth learning.
and a shop manual helps , don,t guess, track down the problem with the meter.
whats your oil and fuel pressure and engine temp when the failure occurs?
verify your electrical connections to the distributor and coil, get out a multi meter and verify voltage from alternator and coil are good ,verify the oil pressure and oil pressure sensor near the distributor are functioning.
remember the ignition shuts off if the oil pressure drops below 4 psi.
be sure you check both ends of the battery cables , a loose connection can and does cause odd issues.
do you lose voltage at the coil?
do you still have spark at the plugs?
have you tested the MAF?
your electrical issue sounds like a loose ground or bad electrical connector at this point, the loose or busted G104-g107 grounds located on the rear of the engine are a common source of that issue with that symptom, of the car just dropping dead
http://garage.grumpysperformance.co...urrent-flow-grounds-and-more.3504/#post-54625
http://garage.grumpysperformance.co...hooting-tip-for-electronics.11317/#post-51557
If your chasing an intermittent, engine miss or stumble, youll need to logically isolate and test each potential source, and while it might be related to fuel pressure, carburetor float levels or crud in the carburetor fuel bowls, or a vacuum leak, on a hose or the brake booster, or fuel pressure or volume of fuel delivery or the carb fuel level, you might also be dealing with a loose electrical connection , on the battery , other wiring or system ground in the cars ignition system or sensors, or something simple like water in the fuel, or a clogged fuel filter, the point here is LOGICALLY ISOLATE AND TEST THE POTENTIAL OPTIONS, AND IT HELPS TO HAVE A FACTORY SHOP MANUAL< A MULTI METER A VACUUM GAUGE AND TAKING NOTES WON,T HURT EITHER
potentially useful threads, and a bunch of useful sub links, logical step by step testing will isolate the cause
http://garage.grumpysperformance.com/index.php?threads/chasing-a-crazy-electrical-glitch.986/
http://garage.grumpysperformance.co...g-tpi-crossfire-or-lt1-vette.1401/#post-39419
viewtopic.php?f=32&t=1401
viewtopic.php?f=80&t=728&p=1025&hilit=sensors+camaro#p1025
viewtopic.php?f=32&t=2697
viewtopic.php?f=32&t=6011&p=18597#p18597
viewtopic.php?f=32&t=168
viewtopic.php?f=32&t=596
viewtopic.php?f=32&t=661
viewtopic.php?f=55&t=606&p=1865&hilit=injector+ohms#p1865
1985-1991: ECM Codes
Code #12: Normal No Codes.
Code #13: Open Oxygen Sensor Circuit.
Code #14: Coolant Sensor Circuit Low.
Code #15: Coolant Sensor Circuit High.
Code #21: Throttle Position Sensor High.
Code #22: Throttle Position Sensor Low.
Code #23: Manifold Air Temperature Circuit High.
Code #24: Vehicle Speed Sensor.
Code #25: Manifold Air Temperature Circuit Low.
Code #32: EGR System Failure.
Code #33: Mass Air Flow Sensor High.
Code #34: Mass Air Flow Sensor Low.
Code #36: Mass Air Flow Sensor Burn-Off Function Fault.
Code #41: Cylinder Select Error.
Code #42: Electronic Spark Timing.
Code #43: Electronic Spark Control.
Code #44: Lean Exhaust indication.
Code #45: Rich Exhaust Indication.
Code #46: Vehicle Anti Theft Fault.
Code #51: Faulty Mem-Cal
Code #52: Fuel Calpak Missing.
Code #52: (1990-91 Corvette Only): Engine Oil Temperature Sensor Low.
Code #53: System Over Voltage.
Code #54: Fuel Pump Circuit Low Voltage.
Code #55: Defective ECM.
Code #62: Engine Oil Temperature Sensor Circuit High.
having the correct shop manual helps a great deal, but common sense (logic) in testing and tracking down electrical problems is a skill worth learning.
and a shop manual helps , don,t guess, track down the problem with the meter.
whats your oil and fuel pressure and engine temp when the failure occurs?
verify your electrical connections to the distributor and coil, get out a multi meter and verify voltage from alternator and coil are good ,verify the oil pressure and oil pressure sensor near the distributor are functioning.
remember the ignition shuts off if the oil pressure drops below 4 psi.
be sure you check both ends of the battery cables , a loose connection can and does cause odd issues.
do you lose voltage at the coil?
do you still have spark at the plugs?
have you tested the MAF?
your electrical issue sounds like a loose ground or bad electrical connector at this point, the loose or busted G104-g107 grounds located on the rear of the engine are a common source of that issue with that symptom, of the car just dropping dead
http://garage.grumpysperformance.co...urrent-flow-grounds-and-more.3504/#post-54625
http://garage.grumpysperformance.co...hooting-tip-for-electronics.11317/#post-51557
If your chasing an intermittent, engine miss or stumble, youll need to logically isolate and test each potential source, and while it might be related to fuel pressure, carburetor float levels or crud in the carburetor fuel bowls, or a vacuum leak, on a hose or the brake booster, or fuel pressure or volume of fuel delivery or the carb fuel level, you might also be dealing with a loose electrical connection , on the battery , other wiring or system ground in the cars ignition system or sensors, or something simple like water in the fuel, or a clogged fuel filter, the point here is LOGICALLY ISOLATE AND TEST THE POTENTIAL OPTIONS, AND IT HELPS TO HAVE A FACTORY SHOP MANUAL< A MULTI METER A VACUUM GAUGE AND TAKING NOTES WON,T HURT EITHER
potentially useful threads, and a bunch of useful sub links, logical step by step testing will isolate the cause
http://garage.grumpysperformance.com/index.php?threads/chasing-a-crazy-electrical-glitch.986/
http://garage.grumpysperformance.co...g-tpi-crossfire-or-lt1-vette.1401/#post-39419
viewtopic.php?f=32&t=1401
viewtopic.php?f=80&t=728&p=1025&hilit=sensors+camaro#p1025
viewtopic.php?f=32&t=2697
viewtopic.php?f=32&t=6011&p=18597#p18597
viewtopic.php?f=32&t=168
viewtopic.php?f=32&t=596
viewtopic.php?f=32&t=661
viewtopic.php?f=55&t=606&p=1865&hilit=injector+ohms#p1865
1985-1991: ECM Codes
Code #12: Normal No Codes.
Code #13: Open Oxygen Sensor Circuit.
Code #14: Coolant Sensor Circuit Low.
Code #15: Coolant Sensor Circuit High.
Code #21: Throttle Position Sensor High.
Code #22: Throttle Position Sensor Low.
Code #23: Manifold Air Temperature Circuit High.
Code #24: Vehicle Speed Sensor.
Code #25: Manifold Air Temperature Circuit Low.
Code #32: EGR System Failure.
Code #33: Mass Air Flow Sensor High.
Code #34: Mass Air Flow Sensor Low.
Code #36: Mass Air Flow Sensor Burn-Off Function Fault.
Code #41: Cylinder Select Error.
Code #42: Electronic Spark Timing.
Code #43: Electronic Spark Control.
Code #44: Lean Exhaust indication.
Code #45: Rich Exhaust Indication.
Code #46: Vehicle Anti Theft Fault.
Code #51: Faulty Mem-Cal
Code #52: Fuel Calpak Missing.
Code #52: (1990-91 Corvette Only): Engine Oil Temperature Sensor Low.
Code #53: System Over Voltage.
Code #54: Fuel Pump Circuit Low Voltage.
Code #55: Defective ECM.
Code #62: Engine Oil Temperature Sensor Circuit High.
Last edited by a moderator:
8
87vette81big
Guest
The last code 51 Mem Cal Failure is most interesting.
It does not show up often at all.
I have a 87 C4 Vert. Very similar to your 88.
Only time I had seen code 51 come up on my car when I was tuning experimenting with Craig Moates Ostrich 2 Emulator.
I was reworking the spark tables.
Faster electronic advance & shutting down the ESC & Knock sensor intentional.
Check all grounds as Grumpy advises.
Especially ECM Grounds.
MSD 7-pin ignition module used now ???
Code 42 ESC , electronic spark control failure.
Has me wondering there also.
Brian
It does not show up often at all.
I have a 87 C4 Vert. Very similar to your 88.
Only time I had seen code 51 come up on my car when I was tuning experimenting with Craig Moates Ostrich 2 Emulator.
I was reworking the spark tables.
Faster electronic advance & shutting down the ESC & Knock sensor intentional.
Check all grounds as Grumpy advises.
Especially ECM Grounds.
MSD 7-pin ignition module used now ???
Code 42 ESC , electronic spark control failure.
Has me wondering there also.
Brian
8
87vette81big
Guest
I am a fair versed EFI C4 OBD 1 Tuner but not stellar at it.
HYPERTECH EPROM Chip may have failed .
GM Used special extra hifh quality EPROM CHIPS.
MEANT TO LAST 50+ Years under ideal conditions.
After market tuned chips programmed or you program yourself not as high quality near indefinate lasting.
HYPERTECH EPROM Chip may have failed .
GM Used special extra hifh quality EPROM CHIPS.
MEANT TO LAST 50+ Years under ideal conditions.
After market tuned chips programmed or you program yourself not as high quality near indefinate lasting.