I have a frustrating crank-no-start problem with my Ford SuperDuty that has stumped several mechanics, nobody can fix it.  Throwing parts it at hasn't helped. Need someone really competent who understands Ford V10 SuperDuty trucks.

PM Sent

(.)

I don't have a Ford v10 but have been looking for a good mechanic since Japanese Auto City and Tony's both closed.

All the places in Alexandria I've checked give me estimates that are 2-3x what they should be.

I'm a dealer tech more central Va.
The V10 is a pretty simple truck.
Do you have fuel pressure?  If you spray some gum cutter in the intake with it start for a second or two?
Crank signal? that's what tells the pcm to fire the coils and injectors.
Is there power at 1 side of the coil and 1 side of the injector with the key on?
Does the check engine light even light up when key is in run position? PCM awake?

Try Dave’s Automotive in Chantilly

I am assumed from the beginning it was a fuel pressure (bad assumption). Replaced the fuel pump and the fuel pump regulator to no avail. It appears to have good fuel pressure, because once you start it, it runs very well, idles well, no issues with anything, full power, etc.



Crank signal? that's what tells the pcm to fire the coils and injectors.

Had 3 mechanics look at it.  The first one thinks it's the crank pos sensor. The second one it's the camshaft pos sensor. The third one thinks it's bad gas.  It has been sitting for 2 years, driven  every few months. I pumped out most of the gas out, and put fresh gas in it. He said it does not smell right and that bad gas mixed with good gas and still no good. And I had the engine started about 3 months ago but never since then. It just cranks endlessly.

I don't know how to check crank signal. Other than via the Forscan software.  Will take a shot at it tomorrow.

here is the thing. When I do get it started, it starts easily a few hours after that initial start. But if it seats overnight, it's back to square one. I don't know what that means.  Losing fuel pressure? But the pump is new.  there is no fuel filter. It's inside the fuel pump. The entire fuel line has been looked at. Probably good to measure the fuel pressure anyway.

The reason I don't think it's bad gas is because it did that exact same thing when I got a full tank of fresh gas. It still would not start the next day.

Here is another clue: It starts easier if I pump the gas pedal. Which makes no sense as it's a 2012 with no carb in it. And has no IAC valve either.  I thought it was the engine coolant temperature sensor but then realized 2012 does not have an  ECT sensor. Nor IAC.

Is it a sensor? A ground issue? A vacuum leak? It could be any of the 100 and 1 things.

No, it does not start with ether sprayed directly into the throttle body. One of the above repair people thinks it's getting no spark and points to crank or cam sensors. I think he is just guessing.  



No CEL when key is on, yeah PCM engages. Or so I think. PCMs rarely go bad. Not sure about the coils/injectors. Not sure how to pull the voltage. Tach moves 100 rpms when I try to start it. One mechanic said it has no spark but I don't know how he got to that conclusion.

I think my best angle of attack is to try to replace the crank pos sensor, then camshaft pos sensor and then pump out the gas. Or maybe there is something else I am missing. I need someone to take ownership of the problem and just fix it.  

I think I've read every article about V10's crank-no-start issue from the beginning of the Internet.

I just got Forscan software and the adapter and will try to look at the live data to see what's malfunctioning hopefully that will shed some light on it.

I highly recommend Drew at Walt’s Auto Repair in Manassas Park.

So I installed ForScan and got the live data for it:

Not sure that I am looking at the right values. I think Camshaft position sensor is cleared. It's not signaled as faulty. The first one in the list.
I am not sure which value correlates to the Crank Position Sensor. ENG_CRANK?
I added everything that seemed relevant. Still no real clue as to what is not functioning. I added all the 10 injectors, they are not flagged as faulty as seen below.
What is the list of items I need to add to the watch list for the crank-no-start condition?

The only thing that jumps at me is the IAT at -40C, it can't be that cold. Looks like it stayed -40C even when cranking. It was 25C outside, with the engine being cold so not far off from the outside temp?
Intake Air Temperature -- would that sensor prevent it from starting?

Anything else I need to add?




This one is when cranking the engine:





And that's the table view:

Still not clear if the AIT sensor is the cause of the no-start position but it seems to generate a bad value for sure. And if it's failed, why doesn't the PCM just use default values?

Apparently Intake Air Temperature is built into the MAF sensor, which has bad writing. I ordered the replacement writing but have not installed it yet.


https://www.easycarelectrics.com/will-iat-sensor-cause-no-start/

The air temperature sensor will not cause a no-start condition, however, it may make it difficult to start. The IAT sensor measures the temperature of the air intake and sends a signal to the engine control unit (ECU). If the air temperature sensor is not performing properly, the engine control module will not be able to properly adjust the fuel mixture, making it difficult to start the engine. For the bad IAT sensor, the ECM will use pre-determined settings for air/fuel mixture and ignition timing. The bad sensor result in decreased performance and fuel economy.

The engine’s hard starting while it’s cold is one of the notable symptoms of a bad intake air temperature sensor. The engine became challenging to start as a result. The engine may run rough if the IAT sensor is not operating properly. This may result in issues including stalling, sluggish acceleration, and power loss. You might have an issue with the throttle body. It’s a good idea to get your car examined by a car repair or mechanic if your engine is running rough or you’re having trouble starting it.

Is there a Schrader valve on the fuel rail? Have you checked fuel pressure when it won't start?

just saw this thread. I recommend loudoun motors behind dulles airport if you are still looking for a shop.