Hey guys, I'm in a tough spot and this is my last ditch effort before handing the car over to a mechanic to have it fixed. I have a 1999 Ford Expedition XLT 5.4L. We fixed a no start issue by changing the crank sensor and CHT sensor. The diagnstics show the engine is reading at -40 degrees and pumping too much fuel on startup. It can now only start with the accelerator pressed to the floor. From what I understand, the ECT sensor was scrapped on the 1999 model. Any ideas on a fix?

 

For the 2-valve engine there is a cylinder head coolant temperature sensor that is sending this -40 reading back to the ECM. You have to remove the upper intake manifold to be able to access this sensor. If this is the CHT sensor you said you replaced, then maybe the connector isn't on all the way or one of the pins is damaged.

 

Awesome. Thanks for the tip alloro. I'll check it out today after work and post an update.

 

Just FYI, the sensor I replaced was pretty much right behind the alternator. I took that out when I replaced it. You're referrig to a different one now?

 

I believe the one right behind the alternator is the coolant temperature sensor. The CHT (cylinder head temperature) sensor sits under the intake manifold on one of the heads, on my '05 it's on the passenger side, not sure if it's the same on the '99. You'll have to remove the intake manifold in order to gain access to that sensor.