Folks, I need a little help trying to diagnose and engine problem.

The last two times I've driven the car it has just died on me. First time was sitting at a stop light. The most recent was while cruising at 20 mph. First time it died, I got it restarted after setting for 20 minutes or so. The second time it had set over night and I was able to restart it the following day. Fuel pump does runs when cycling the key.

History: engine was recently replaced using a short block assembly from Texas Speed and all my existing heads, intake etc.

And no CEL or codes stored in the PCM after either occurrence.

Anyone else have a similar issue and figure out what would cause this problem?

 

It could be your fuel pump. If you let your gas go below a 1/4 .Pump heats up and shorts the wires.

 

No, tank was almost full when it died the second time. Was also filled up just prior to (20-30 minutes) it dieing the first time.

 

When it dies, does it crank and not start or not crank? If it cranks, you will need to check for spark, fuel pressure and injector pulse. If you have fuel pressure, but no injector pulse or spark, the most likely problem is a failing crank sensor. If you have access to a scanner, you would see no rpm signal. Also verify IAT, CT, TP and MAF readings are correct.

 

Yes, it cranks but no start. Fuel pump initializes and I have fuel pressure.
Will a bad crank sensor throw a code? I assumed it would.

 

It died again today. This time I was able to log some info and discovered no rpm signal while cranking. It appears the issue is with the crank sensor. The puzzling part is why the problem is intermittent??? If the sensor failed it would be dead all the time.

 

Crank sensors can cause all kinds of intermittent problems, especially stalling and no start. I would replace it with an ac delco sensor. Be carefully removing it. You do not want it breaking off in the block, no fun. You will need to do the crank relearn procedure.

 

I know for a fact that crank sensors can fail intermittently and do not throw codes. Ask me how I know. When it began happening to me, it took me almost the whole summer to find that my crank position sensor was bad. I was afraid to drive the car because it could stall any time at any speed and not throw a single code.
Secondly, I did not need to have a crank sensor relearn performed. I guess this can be different with your car but most people who have changed out their crank sensors did not need a relearn. It's probably a good idea to have one done anyway, however.

Check out the thread I started last year. It may be an interesting read:

http://forums.corvetteforum.com/c5-t...dm-u1016h.html

 

thanks for posting. It's good to know somebody else had the exact same symptoms I am experiencing.

The third time mine died it did throw a code. I believe it was P0335.

 

Agreed, last few GM's I've had did this and it was the crank sensor. They did not throw a code till they got REAL sick. I have better scanners now so I can see the crank pulses. There is no need for any relearn on any GM I've ever replaced the sensor on.

 

Good info to know. Thanks

 

YEP,,,,,,,,,,,, That would be a crank Sensor.

I strongly recommend examining the wires, the connector and the Female pins inside the connector and make sure the wires are not chaffed and the female pins are not overly spread and not making the requires electrical connections.

Bill

 

Yes, I'm hoping the car will run long enough to get it to a local shop that will be doing all these checks while replacing the sensor itself. Maybe then I can start to enjoy driving the car again without worry of it just dieing at any given moment.

Does anyone know of the OE spec for the clearance between the end of the crank sensor and the reluctor wheel?

 

I checked, there was no spec given. There is no adjustment. Just replace it and torque to 18ftlbs.

 

2002 Chevrolet Corvette V8-5.7L VIN S
Vehicle » A L L Diagnostic Trouble Codes ( DTC ) » Testing and Inspection » P Code Charts » P0335
P0335
CIRCUIT DESCRIPTION
The crankshaft position (CKP) sensor signal indicates the crankshaft speed and position. The CKP sensor is connected directly to the powertrain control module (PCM) and consists of the following circuits:
The 12-volt reference circuit
The low reference circuit
The CKP sensor signal circuit
CONDITIONS FOR RUNNING THE DTC
DTCs P0101, P0102, P0103, P0341, P0342, or P0343 are not set.
The camshaft position (CMP) sensor is in transition.
The mass airflow (MAF) is more than 3 grams per second .
The ignition switch is in the crank mode.
CONDITIONS FOR SETTING THE DTC
The PCM does not receive signals from the CKP sensor for at least 4 seconds .

ACTION TAKEN WHEN THE DTC SETS
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
DIAGNOSTIC AIDS
The following conditions may cause this DTC to set:
Poor connections, or terminal tension at the sensor-Refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.
Crankshaft reluctor wheel damage
Improper installation of the crankshaft reluctor wheel
The sensor coming in contact with the reluctor wheel
The engine runs out of fuel
Excess crankshaft end play causes the CKP sensor reluctor wheel to move out of alignment with the CKP sensor. This may result in one of the following conditions:
A no start
A start and a stall
Unstable performance
For an intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies\Intermittent Conditions

TEST DESCRIPTION


Steps 1-8



Steps 9-17



The numbers below refer to the step numbers on the diagnostic table.
This step simulates a CKP sensor signal to the PCM. If the PCM receives the signal, the fuel pump will operate for 2 seconds . If the fuel pump operates, the condition involves terminal contact at one of the following components:
The CKP sensor
The CKP sensor reluctor wheel
This test determines if the CKP sensor signal circuit is faulty or if the PCM is faulty.

 

What he said.

 

Thanks. I just wanted to be sure there is no difference in the length of the sensors between the older generation engines and the newer. I currently have installed the original sensor from my 2002 block but the new engine is a bored out 5.3L aluminum block so it's a newer generation block.