No tach, car intermittently dies

[77k5]

'96 Z28 LT1, tach started sitting at zero whether the car is running or not yesterday.

Motor has cut out several times while driving and has had one long (15 sec) start.

Car runs fine otherwise, other than the tach sitting at 0.

CEL shows P0372

Distributor is an MSD unit that's ~18 months old.


Ideas?

[Orcus79]

check the fuses first, the go from there. Any aftermarket alarms, gauges or stereo?

[Smittro]

'96 Z28 LT1, tach started sitting at zero whether the car is running or not yesterday.

Motor has cut out several times while driving and has had one long (15 sec) start.

Car runs fine otherwise, other than the tach sitting at 0.

CEL shows P0372

Distributor is an MSD unit that's ~18 months old.


Ideas?

My manual is'nt showing such a code..(last code shown for the P0300's is listed as P0358: control circuit coil 8) Hmm strange, well I guess I'd start with check out your wire harness for damage and a Orcus said take a peek @ the fuses.. I dunno..

[77k5]

check the fuses first, the go from there. Any aftermarket alarms, gauges or stereo?

The tach was intermittent at first and now appears to have stopped working. The motor isn't getting spark or fuel at some point, but again, intermittent. I'll check the fuses because they're so easy but AFAIK they never cause intermittent problems.

My manual is'nt showing such a code..(last code shown for the P0300's is listed as P0358: control circuit coil 8) Hmm strange, well I guess I'd start with check out your wire harness for damage and a Orcus said take a peek @ the fuses.. I dunno..

Are you sure you're looking at the manual for an LT1 and not an LS1?


Thanks guys

[Smittro]

The tach was intermittent at first and now appears to have stopped working. The motor isn't getting spark fuel at some point, but again, intermittent. I'll check the fuses because they're so easy but AFAIK they never cause intermittent problems.



Are you sure you're looking at the manual for an LT1 and not an LS1?


Thanks guys

My manual lists codes across the board. However Haynes has not always been known for accuracy..

[Smittro]

Here ya go:

DTC P0344 Camshaft Position Sensor Circuit Intermittent
DTC P0350 Ignition Coil Primary/Secondary Circuit Malfunction
DTC P0351 Ignition Coil 1 Control Circuit
DTC P0352 Ignition Coil 2 Control Circuit
DTC P0353 Ignition Coil 3 Control Circuit
DTC P0354 Ignition Coil 4 Control Circuit
DTC P0355 Ignition Coil 5 Control Circuit
DTC P0356 Ignition Coil 6 Control Circuit
DTC P0357 Ignition Coil 7 Control Circuit
DTC P0358 Ignition Coil 8 Control Circuit
DTC P0359 Ignition Coil I Primary/Secondary Circuit Malfunction
DTC P0360 Ignition Coil J Primary/Secondary Circuit Malfunction
DTC P0361 Ignition Coil K Primary/Secondary Circuit Malfunction
DTC P0362 Ignition Coil L Primary/Secondary Circuit Malfunction
DTC P0370 Timing Reference High Resolution Signal A Malfunction
DTC P0371 IC 24X Reference CKT Too Many Pulses
DTC P0372 IC 24X Reference Circuit Missing Pulses
DTC P0373 Timing Reference High Resolution Signal A Intermittent/Erratic Pulses
DTC P0374 Timing Reference High Resolution Signal A No Pulses
DTC P0375 Timing Reference High Resolution Signal B Malfunction
DTC P0376 Timing Reference High Resolution Signal B Too Many Pulses
DTC P0377 Timing Reference High Resolution Signal B Too Few Pulses
DTC P0378 Timing Reference High Resolution Signal B Intermittent/Erratic Pulses
DTC P0379 Timing Reference High Resolution Signal B No Pulses
DTC P0380 Glow Plug/Heater Circuit "A" Malfunction
DTC P0381 Glow Plug/Heater Indicator Circuit Malfunction
DTC P0382 Exhaust Gas Recirculation Flow Malfunction
DTC P0385 Crankshaft Position (CKP) Sensor B Circuit
DTC P0386 Crankshaft Position (CKP) Sensor B Performance
DTC P0387 Crankshaft Position Sensor B Circuit Low Input
DTC P0388 Crankshaft Position Sensor B Circuit High Input
DTC P0389 Crankshaft Position Sensor B Circuit Intermittent
DTC P0400 Exhaust Gas Recirculation Flow Malfunction
DTC P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient
DTC P0402 Exhaust Gas Recirculation Flow Excessive Detected
DTC P0403 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit
DTC P0404 Exhaust Gas Recirculation (EGR) Open Position Performance
DTC P0405 Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage
DTC P0406 Exhaust Gas Recirculation Sensor A Circuit High
DTC P0407 Exhaust Gas Recirculation Sensor B Circuit Low
DTC P0408 Exhaust Gas Recirculation Sensor B Circuit High
DTC P0410 Secondary Air Injection (AIR) System
DTC P0411 Secondary Air Injection (AIR) System
DTC P0412 Secondary Air Injection (AIR) Solenoid Relay Control Circuit Bank 1
DTC P0413 Secondary Air Injection System Switching Valve A Circuit Open
DTC P0414 Secondary Air Injection System Switching Valve A Circuit Shorted
DTC P0415 Secondary Air Injection System Switching Valve B Circuit Malfunction
DTC P0416 Secondary Air Injection System Switching Valve B Circuit Open
DTC P0417 Secondary Air Injection System Switching Valve B Circuit Shorted
DTC P0418 Secondary Air Injection (AIR) Pump Relay Control Circuit Bank 1
DTC P0419 Secondary Air Injection (AIR) Pump Relay Control Circuit Bank 2
DTC P0420 Catalyst System Low Efficiency
DTC P0421 Warm Up Catalyst Efficiency Below Threshold (Bank 1)
DTC P0422 Catalyst System Low Efficiency Bank 1
DTC P0423 Heated Catalyst Efficiency Below Threshold (Bank 1)
DTC P0424 Heated Catalyst Temperature Below Threshold (Bank 1)
DTC P0430 Catalyst System Low Efficiency Bank 2
DTC P0431 Warm Up Catalyst Efficiency Below Threshold (Bank 2)
DTC P0432 Catalyst System Low Efficiency Bank 2
DTC P0433 Heated Catalyst Efficiency Below Threshold (Bank 2)
DTC P0434 Heated Catalyst Temperature Below Threshold (Bank 2)
DTC P0440 Evaporative

[Smittro]

http://www.grandprixforums.net/websi..._Code_List.pdf

[77k5]

Should've mentioned I know what the code means, I just don't know where to look to start diagnosing this

[thearborbarber]

Opti is probably going out.

http://www.f-body.com/forum/showthread.php?t=15811

[77k5]

Checked the connector on the intake manifold and it's good, the MSD opti doesn't have a connector at the distributor itself, its wired directly.

Anything else I can check before I pull the distributor and send it in to MSD?