Hello I have a 2000 ford f150 4.6 auto, with 185k.The truck runs well until the temp gauge on the dash hits the center between hot and cold. From a cold start it runs well up until that point where it will studder and stall out. When I try to restart the truck its not getting to the point where it wants to turn over. After sitting almost 20 minutes the truck will start back up and the temp gauge will start at a little above warm but will die again when it reaches optimal temp. During the times I am driving the truck it will run fine but will start to run rough when sitting at a stop light and at optimal temp. During take off, it will accelerate but will loose power. Pushing the pedal more does nothing but cause the truck to back fire and cause the motor to die out quicker without return to regular idle. The same 20 minute cool down also has to happen for it to restart. During diagnosis I have tested the fuel pressure from the rail and have a steady 38-40 PSI from cold start through when the truck dies at optimal temp. I have also checked the pcm relay and the fuel pump relay, both are working good. Before this problem I had the computer register a lean code for bank 2 sensor 1 which cleared upon a 02 sensor install. The last time the truck was not having this problem was when I had changed the heater core from the old owner who had bypassed the hoses. The parts that have been changed include the drivers side 02 sensor, Dpfe sensor, and cleaning of the IAC and throttle body. Back in November of 2021 I had changed the COP and spark plugs. At this point I am going to check the Crankshaft sensor, Camshaft sensor, Maf sensor, TBP sensor, and the temp sensor. I don't know if this would help but the outside temp at the time of stall was 71 degrees (F). Any help that can be given would be greatly appreciated.
Thank you
DJ
Also, the check engine light is off and the scanner shows no code found.
Have you replaced the engine coolant temperature sensor?
Hello, after looking at manual for this truck I had found out today that the truck does not have a ect sensor but a Cylinder head temp sensor. This sensor is right next to the rear left of the manifold next to the valve cover. I had not had a chance to check the sensor out yet. I had disconnected the heater hose and put them back to when the previous owner had it bypassed. After starting the truck it had stalled after about ten minutes, less than it usually takes to warm up at the line right above cold. Then the theft light had come on and the odometer showed dashes. The theft code is a 16. I had checked the 15 amp fuse for the pcm and fuel pump. They are in good condition. I suspect that the relays for the fuel pump and the PCM had gone bad. After switching them the fuel pump would not build pressure on the gauge, but the theft light had gone out. I am going to run and pick up two relays and see if that may be the cause for the weird stalling.
Thank you
DJ
What does live data look like when the engine stalls out?
