Engine Stalls

[fixkick]

bucking is spark
fuel loss in like is smooth and gradual.
next time it stalls, with scan tool hooked up,, just pull over. and leave key on, and check for DTC errors, while key is on. still.
i dont think the tool stores pendings. (I DONT know for sure)
you press the keys for pending and it scans the PCM for just that, and shows you if there are pendings or live DTC errors.
If the failures are solid , the PCM stores them in it's DTC RAM. and will no clear until the , x number of driving cycles, each DTC has its own drive cycle count rule .
some clean too fast.

P0300 will stick there awhile, P0300,301,302,303 and 304, (300 is misfiring all 4, 301 is cylinder 1. etc.
the 340 and 355,IIRC, they love to reset fast. (CAM AND CRANK SENSORS) THAT I SUSPECT NOW.

the PCM if it sees, the CKP sensor fail, it will store it but if it sees it go away fast, it clears fast,TOO,, same with CMP sensor.
that is why the Pendings are so key for CKP/CMP..... FREEZE FRAME IS HANDY TOO, it shows what other key sensors did, at the last DTC stored.
Freeze frame is like looking in a key hole.

are you sure your COP boots are ok.?
pull the cops make sure there are no cracks or carbon tracking in the boots.
take a look at the CMP sensor, do you see a bolt there for it, and any wires black to any CMP mounts or bolts there, (besides the connector )?

tricks to try, simple.,
remove the CMP, on the end if it can be mud, this mud is metal dust (iron) and if it builds up it misfires, wipe if off with a rag and its fixed. a zero buck fix.

same with the cranks sensor , both are non adjustable. a blessing that.

if a cop fails, you get like 1/3 horse power or less, 2 cylinders dragging 2 dead is way less that 1/2 power,

im really sad the PCM will not pop P03xx errors... it must if you do it right, leave key on, wait say 2 o 5 minutes and scan the stalled engine, a DTC normal scan then pending scan.
be so cool to see that, and we can nail this flaky part what ever it is.

some folks get so mad, 2 new cops/ckp and cmp. Im sure it's thermally related. gets hot and fails. sure seems so.


Pendings are DTCs real, that are not stored in PCM memory yet,, its on the threshold of failure.

good luck in your testing ! cheers.

the boot must not be cracked or carbon tracked,

[fixkick]

boots can be bought , all by them selves.

like this, every 100k? miles.? wow NKG price, what a deal,
https://www.rockauto.com/en/catalog/chev...boot,10150

[Joe Tracker]

boots can be bought , all by them selves.

like this, every 100k? miles.? wow NKG price, what a deal,
https://www.rockauto.com/en/catalog/chev...boot,10150

The engine stalled as I was idling and preparing to back out of the garage. The Innova 3160 stored a Diagnostic Trouble Code (DTC) and Freeze Frame Data. I am am still not confident in my ability with the Innova, so let me provide the DTC screen content to you:

P0340. Chevrolet Stored

*CMP (Hall) sensor signal circuit is open or shorted to ground.
*CMP (Hall) sensor ground circuit is open.
*CMP sensor power circuit is open (test power from MFI relay)
*CMP sensor is damaged or has failed.
PCM has failed (PCM provides a VREF signal to sensor)
P0340 (1/1) stored
Intake Camshaft Position Sensor Circuit
Severity 2 of 3
Repair immediately if drivability issues are present. Threat to essential system present. Threat to essential system components if not repaired as soon as possible.

Freeze Frame:

Fuel: OL
MAP: 30 (inHg)
Eng RPM: 0
Veh Speed: 0
ECT: 70 degrees
STFT B1: 0.0%
LTFT B1: -3.9%

Also note that the "CAT" icon has turned from green to red and is blinking.

Please recall that I previously noted the CMP was covered with grime and oil from previously a repaired leak (I have corrected all oil and fluid leaks). The car ran a little better after I cleaned the cable connected and ground connection of the Camshaft Position Senor.

What are next steps?

Thanks for all you help.

Joe Tracker

[fixkick]

BINGO to the max.
340
we now know what is wrong. (object level)

a cmp is like $50 , if cleaning it does not cure 340s and wires are not damaged, or pins, on the connector, its bad.
the get hot and fail, its common ,

sure beats a bad ECU. , or bad maf, $$$$$$$
nice work , nailing it, very good.

[fixkick]

The trick is catching it overheat and fail ,, and bet it clears fast, when it runs good cold. hiding that failure.
cheers and happy trails to you !

[Joe Tracker]

The trick is catching it overheat and fail ,, and bet it clears fast, when it runs good cold. hiding that failure.
cheers and happy trails to you !

Yes - it does run well cold. You should know that the yellow LED right below the Innova's screen is illuminated. I think this means that the DTC stored is a pending code. If so, it confirms that the only codes being generated were pending codes. In this particular case the Innova caught and stored the pending code as well as freeze frame data for the PID's. I am thinking about this correctly?

Do you recommend Rock Auto to purchase a replacement Camshaft Position Sensor?

Thanks again for all your help. There is no way I could have root caused the engine stalls without your help.

Joe Tracker

[fixkick]

here is the 99 shop manual words (but some times only Pendings work here, )

Handling ESD Sensitive Parts Notice
Circuit Description

The camshaft position (CMP) sensor is located at the rear of the cylinder head and consists of a signal generator (a hall element and magnet) and a signal rotor. As the signal rotor turns, a magnetic flux from the magnet is applied to the hall element repeatedly. The hall element generates a voltage that is proportional to the magnetic flux. The PCM uses this pulse/revolution signal in order to determine the engine speed and the position of each cylinder. The PCM uses this signal to control the fuel injectors and the ignition timing.
Condition for Running the DTC

The engine is being cranked.

The engine is running.

Conditions for Setting the DTC

No signal from the CMP sensor for 3 seconds with the PCM receiving an engine start signal.
Action Taken When the DTC Sets

The malfunction indicator lamp (MIL) will illuminate.

The PCM will record operating conditions at the time the diagnostic fails.
This information will be stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC

The MIL will turn OFF after three consecutive drive cycles without a fault present.

A DTC will clear after 40 consecutive warm-up cycles without a fault.

The DTCs can be cleared by using a scan tool or by disconnecting the PCM battery feed.

[fixkick]

any autostore sells this part, or can get it in hours. (from their warehouse)
NAPA, Advanced Auto, Pepboys, Oriellys, and more.
i showed rockauto , only to show how many named manufactures, make it. its large list. most are good, but maybe not the cheapest one with obscure name.

[fixkick]

it has 3 pins, all pins most not damaged or corroded,
power , ground and signal.
this sensor has very strong signals.