i have a 2000 f150 7700 with the 5.4 with 170,000 miles. When I parked the truck at one of my stops today I noticed it was idling at about 1100. I tapped the gas and rpms jumped to about 2000 hung there for about 5 seconds then came back down to 1100. Shut it off, did my work which took about 30 min, went to leave and truck would not start. Finally got it to start by holding the gas all the way down and cranking the heck out of it. Still idiling at 1100 and jumping when you bump the gas. Left it running the rest of the day as I didnt want to be stranded. Got it home but still same problem idling and starting. Check engine light has not come on. any help would be appreciated

 

replaced throttle position sensor yesterday, not it
now replaecing crank position sensor. any other sensors I should replace at a whim

 

Just a guess here but high idle/hard starting may indicate a vacuum leak?

 

will start checking vacuum lines. any certian places to check first? crank sensor did not help. also when all this started temp gauge quit. does that mean somthing?

 

That might mean the cold start circuit is not working correctly--I do not know if the ECU gets its signal from the same sensorbut if so this would in effect make the ECU think the engine is cold and thus increases the idle and enriches the fuel mix. If the newer Fords are like the older ones holding the throttle to the floor is the way you clear a "flooded" motor. Just guessing here, hope it helps. Did you get the gauge to work?

 

temp gauge will jump a little when key is first turned on then drops to bottom and does not come up when engine warms up
UPDATE: PROBLEM FIXED new head temp sensor and runs great