Kahuna6719

My 97 Silverado 5.7L is running the best it ever has since owning it, except for the fact it stalls out while driving after reaching normal engine running temperature. It will restart within a minute of stalling. Plenty of spark and fuel pressure yet i don't know if it is cut off when stalling.There are no codes,backfires,misfires,lack of power,or rough running conditions. I am completely and utterly baffled. Recently I can add camshaft sensor to the list of parts that have not corrected the stalling problem.
Here is a list of the rest.
Delphi Fuel pump, fuel filter, fuel relay, plugs, cap, rotor, wires, air filter, ignition control module, crank sensor, coil, coolant sensor, cats and oxygen sensors, ground straps frame to block, fuel pump to frame. Thoroughly checked wiring at all sensors and connectors for cracks where wire could short. Don't really want to change computer, ignition switch or injectors but there is not much else left.

Sorry to bother you guys on the Hoe-Burb page but you have the same drive train as me and i'm desperate to figure this out and not be afraid of breaking down on the side of the road and towed for the fifth time.
I have taken it to two garages spoken with friend at a dealership in service and paid an online GM supposed expert with no luck. I am not totally discouraged yet seeing I got almost 200K trouble free miles and I knew these parts should have been replaced at some point.
I do have an exhaust leak after the new converters was wondering if exhaust pressure would have any bearing on the problem. And how important is exhaust pressure? <label for="rb_iconid_6"></label>

EinST

On a 1997 the ignition switch is a distinct possibility. One leg may be putting out less voltage, just at the threshold where the PCM may cut out. Are you capable of doing some electrical troubleshooting with a digital multimeter (or analog VOM, makes no difference)?

Kahuna6719

Yes I have a multimeter. I would love to perform some tests if you could give me some suggestions.

EinST

Okay, then, find a good reference voltage in and around the I/P fuse block (black probe on something that screws into the chassis and red probe into the probe hole on the CIG LTR fuse). It should be very close to the voltage across the battery terminals.

Using the same grounding point, measure the voltage at the TRANS fuse and CRUISE fuse with key in RUN and engine off (may want to go slowly back and forth between OFF and RUN).

Now, move to the underhood fuse block. Pick a grounding point near the fuse block and then measure the voltage at the battery positive terminal. It should be very close to the voltage across the battery terminals.

Using the same grounding point, measure the voltage at the IGN-E fuse, ENG-1 fuse, and ECM 1 fuse with key in RUN. Get a helper to move the key slowly between OFF and RUN.

All these fuses except the CIG LTR fuse are downstream of the ignition switch. If any voltage reading are in the single digits, you'll have to get to the ignition switch and measure what's being supplied to it.

Kahuna6719

Ok, I will try those and let you know the outcome thanks for the details.

Kahuna6719

I checked all the points you mentioned above and the voltage was all around 12 plus or minus half a volt. This test should tell me if ign. switch is ok ?

Kahuna6719

I have a pretty good exhaust leak after the newly replaced Cat. Conv. and new oxygen sensors do you think that could cause the stalling. The new Y pipe and Cats. just don't align good enough to get a good seal I have replaced the gasket three times this past year at $26 a pop. What a rip off for such a small gasket that just won't hold up. Last time I tried doubling the gaskets hoping for a better result no such luck. Right now I just want to keep it from stalling out though. Thanks EinST

EinST

An exhaust leak around O2 sensors usually results in one or more trouble codes. In fact, I wonder why that hasn't happened if the leak were that bad. By "no codes," are you going by the MIL indicator or have you actually scanned it (good OBD connection and all)?

Kahuna6719

The leak is after Cats and 02 Sensors and yes good connection on my OBD scan tool and no codes

EinST

Years ago I used to have a laptop with an OBD dongle that I'd use to capture data to disk until a failure occurred, like a poor man's vehicle data recorder. You may want to consider something like that with what's available today. Other than that, try another VCM (be sure to transfer over the EEPROM chip).