2002 Crown Vic, No DTCs.

Car is a 2002 Crown Victoria LX sport with no mods and stock tune. 4.6L SOHC engine, gasoline, 4r70w Transmission.

What happens:
Car cranks and starts up fine and runs good cold. Idle, part throttle, and full throttle, no issue. Cars gets to operating temperature and still does fine. Once car is to operating temperature and you accelerate the car starts to stutter as if it is losing spark or fuel or both. If you immediately go back to very light throttle the car can still be driven, when you accelerate again, then it will stutter/stall more. If you stay in the throttle it will continue and finally die. If you try to restart it will turn over fine but will not stay running, it will continue to stall/stutter. If you wait 2-3 minutes the car will restart and idle fine. If you drive it super easy you might be able to drive but if you accelerate pretty much at all it will die.  If you wait longer with the engine off, ie 10 mins it will drive fine until you begin heavier acceleration.  I believe the issue is related to heat.

The car is not overheating. The coolant level and coolant temps are fine.  I had the stock 195 degree thermostat but now have 180 degree.  No change to the problem. 

I do not have a history of this car because I bought it running like this. The intake has been changed at some point, which is common on these cars.  Does appear to be an OEM intake.

When the stutter/stall occurs the check engine light flashes at each stall. The temp light will illuminate and the check gas cap will flicker. If the OD off light is on during the drive it will reset the light to the off (OD on).

There is no codes in the computer. Also I don't believe the car is going into "failsafe mode" because the temps from both sensors (coolant/cyl. head) are good.  
The computer will still store codes if you disconnect parts, but the problem is not storing any codes.

I have had the car connected with my scanner to watch and record data. All sensors are working as expected and all data looks good. When the stutter occurs the short term fuel trims go +20 or +30 positive for a brief second and return to normal operation around 0. The only data that I would say is weird is that the engine run time resets to 0 at each stutter. When I datalog the car using my SCT x3 and Live Link the datalog will STOP all new data at the first stutter.

This leads me to think that the computer is losing power and restarting. I have bypassed both the ECU and Fuel pump relays and wired them straight to Battery +, I also repined the ECU to have both hot at all times and hot while key is in run position are connected directly to battery +. I also repined all the grounds from the ECU harness back to battery -, but I have removed this at this time, because the issue was unchanged. 

Things I have done:
Coils have been changed with a set from a known good car. Spark plugs inspected as they are pretty new. MAF has been changed with a known good one. Fuel pressure has been monitored with a gauge and is good.
I have changed the ECU with a police P71 and disconnected the ford PATS module (P71 ECU does not use the Ford PATS). Has been returned to stock computer as of now.
I have driven the car with every sensor unplugged and it does the same thing. Of course these throw the appropriate code, but I reset the codes when I plug them back in. Cats are around 500 degrees on both banks. I have wiggled and jiggled every wire I can find and have not found any that are loose. There is no rust or corrosion on any wire or ground that I have found. I have driven the car with the alternator disconnected and alternatively with the battery disconnected.

What I don't think it is:
1. Coils or plugs (known good coils)
2. MAF (known good maf)
3. Overheating of the engine or anything to do with the temp sensors
4. Bad ECU (tried another one)

I'm really thinking something is causing the ECU to restart when hot just have not pinpointed what that is. I have been looking for melted, chaffed, or corroded wire... no luck.

Videos:
drive.google.com/file/d/1Fh4qIfJtG_3NGG6...DaK/view?usp=sharing

drive.google.com/file/d/1ftA7bujL0V0WZ1D...I2H/view?usp=sharing

drive.google.com/file/d/1fuiNUn7nEq6LwqP.../view?usp=drive_link


Any ideas would help.

kxt, I think you're absolutely right that the PCM is shutting down/starting up during your symptoms. Normally I'd go straight for the COP's, but you've already ruled that out.

My next thought is a 5V reference circuit that's shorting to ground intermittently. Harness rubbed through, pinched, like that. Unplugging sensors won't help because the 5V reference can be shorted even with no sensors connected.

I did see in your video that the TPS voltage stays steady during the symptoms, But, I don't think scan data can be completely relied upon if the PCM is shutting down.

For me, your next best move is to find a convenient 5V reference sensor, probe the 5V circuit and watch the voltage on a multimeter while your symptoms are happening. If you see the 5V reference dropping, you know you're on the right track.

Getting the test leads connected and strung into the cabin might be a challenge. Something like this test lead reel might be good (and not just for this, they're handy to have around anyway):

www.amazon.com/dp/B0BPDMWLP6/