Did you have the codes before you replaced the sensor?

 

My point was that a non-functioning coolant sensor can cause poor running or no-start as documented in the post I linked. So I would not rule out that it's related. Non-functioning does not necessarily mean the sensor itself but it could also be an electrical issue.

Things to try:
Measure voltage between signal ground and chassis ground (should be 0) and between the temp sensor feed and chassis ground (should be a little under 5V).
If seeing high voltages, try pulling fuse K in the PDC which is the O2 sensor heaters and see if it makes a difference. Sometimes heater voltage gets on the sensor wires from defective wiring or O2 sensors.

 

[QUOTE=HeyYou;3495497]Did you have the codes before you replaced the sensor?[/QUOTE

So, I went back and checked the OBD scans to see what I had, and when.
After the stalling episodes, I ran the check and report shows just the P0018 (overheat) when I got home. Again, I had been getting these fluctuating temp readings- from ice cold to normal even when the engine was hot.
The check engine/overheat error was occurring periodically even though there was no overheat, by gauge or otherwise...

Just in case it might mean something to someone, it was particularly odd that I noticed when sitting at idle at a light, drive-through, etc- the gauge would peg far left cold- then I would get the check engine/overheat error. Weird, but in retrospect was likely due to the sensor likely being fried from the overheat episode when the hose blew. Truck was running fine, I knew it wasn't overheating nor running cold- but was too busy to eff with the weird temp fluctuations at the time so I put that troubleshooting on the back burner.

As I said, the truck was running normally, started repeatedly without problems after I'd gotten it home after it had stalled twice.
Next day I tried to start it, and that's when it would only crank. I had not changed the sensor at that point; it was only after it wouldn't start that I inspected the sensor. For all I know it could have been operating correctly, it's not till I went to check the connection/connector to it that the plastic basically fell apart which necessitated its replacement.

After trying to start it unsuccessfully a couple of times, ran the OBD again and that's when the 4 codes showed. I can clear the codes, run the scan again and the codes are still there. Disconnected the battery for 15 minutes, still no start, and the codes still there.

I just ran the self-diagnostics "actuator test" on the instrument cluster and there were no errors. So again, I keep coming back to the gauges being inop with the key in the "run" position- which from what I've read means they're not getting data from the ECM.

 

Are you getting "No Bus" in the odometer?

 

When you crank it do you smell fuel?

 

No sir. Bus diagnostics showed no errors, cycled through all tests- gauges, indicator lights, all good.

Thanks, will do this tomorrow.

BTW, no odor of unburned fuel. Not sure that I'd be able to smell it anyway if it were dumping fuel with no spark(?)


Appreciate the help, guys.