2007 3.3l 250hp starting at 3000+ rpm

[pbob42]

got this on a trade - Only YDS code is a 45 - "Shift cut-off switch" that is 100 hours old. YDS data is below. compression is good. got hopes for this motor. Go to start it on the stand and starts at 3000 RPM. I am stumped. Thinking it is the ECU. Thoughts?

This the the YDS data:
Engine Monitor
Monitor Item Result Unit
Engine speed 0 r/min
Intake pressure 99.88 kPa
Intake pressure 29.53 inHg
Throttle position sensor 1 0.771 V
Throttle valve opening (0-90) 5.7 deg
Throttle position sensor 2 2.734 V
Accelerator position sensor 1 0.684 V
Accelerator position sensor 2 0.708 V
Atmospheric pressure 996.2 hPa
Atmospheric pressure 29.5 inHg
Battery voltage (12-16) 12.32 V
Fuel injection duration 0 ms
Ignition timing - deg
Engine temperature (below 120) 18 °C
Engine temperature (below 248) 64 °F
Intake temperature 16.8 °C
Intake temperature 62 °F
Oil pressure 3.8 kPa
Oil pressure 0.6 psi
Intake cam timing (STBD) - deg
Intake cam timing (PORT) - deg
Engine stop lanyard switch OFF

Shift position switch ON
Dual engine system switch OFF
Shift cut-off switch OFF
Overheat thermoswitch OFF
Main switch ON
Main relay ON
Electronic throttle relay ON
Fuel pump relay OFF

 

[99yam40]

I guess these readings are not while the motor was running.
do they change when the motor is running?

 

[boscoe99]

Has it been verified with a tachometer that it is running at 3000 RPM? How long does it run?

 

[dingbat]

Wild ass guess not knowing the acceptable range parameters of said sensors…..the voltage on your accelerator position sensors are 0.024 volt apart. The throttle position sensors are almost 2.0 volts apart

 

[boscoe99]

APS and TPS are within specifications.

 

[pbob42]

runs for about 1 second then I shut it down. 3000 rpm is a guess. could be 4k or 5k. it is quite startling. Started it twice, then again 2 days later. same thing each time. figured i'd get an error code or something to debug. ordered a replacement ECU that is returnable within 30 days. quite a quandary.

 

[boscoe99]

The 3.3 liter F250 is known to race at start up. Will settle down if left alone.

 

[pbob42]

okay. i'll let it run and see

 

[cyclops222]

Basics ?
Check if throttle plate is closed when stopped ?

 

[pbob42]

It is on a stand, no control cables hooked up. Throttle is sprung shut. This is acting like it is wide open throttle to me, but it is definitely closed.

 

[99yam40]

I believe most of injected motors have Idle speed control valve that resets to 100% at shutdown to be ready for the next start.
it should rapidly drop idle RPM once started if that control valve works as it should and there are no other places it is sucking in air

 

[cyclops222]

Some EFI engines do have a Throttle Plate Position Sensor at the the throttle plate. It may be loose and shifted.
Is this a sudden new problem ? No It is a new traded engine.
Why someone sold it ? Does it need all control cables connected ? to run normally ?

 

[boscoe99]

The 3.3 liter F250 has a single electronic throttle valve. No idle air control valve is used.

The electronic throttle valve has two throttle position sensors that are part of it.