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- Dec 28, 2020
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I have an extended cranking situation and looking for any insight. Truck always starts. First try every time. But where my 2016 starts on the first revolution this 2014 may take 3-4 revolutions to fire up.
Does matter if it is hot or cold, sits for a minute or a month.
Cycling the key before cranking does not affect it. Full fuel tank or empty.
No codes ever. Truck has been flawless since new. Put a starter on it and thermostat housing otherwise beyond the EGR DEF issues it has never been touched in it's life.
No additives ever. No bad tanks of fuel, never water in fuel.
Filters changed with motorcraft every 10k since new. been changed numerous times since this condition started.
Batteries have been replaced since this started.
It burns clean, no smoke. No apparent power loss. This last trip my mpg was down to 17.3 instead of the usual 18-18.5 but I also see my intercooler hose off the turbo is leaking pretty bad, so I would imagine a big boost leak like that will affect mileage.
Specs, 2014 F250 186k miles. Deleted with minimaxx but stock fueling. Had this truck for over 6 years now, been doing this for at least a year so last 20-30k miles.
Never had a problem so never had to learn, started reading on a recent 3k mile trip and boy did I learn.
While searching extended cranking I kept coming across CP4 failure as cause. This didn't make sense to me as the condition existed so long how is the truck still running and the only symptom I had was longer cranking.
Here I am into it now. Still no codes. Started thinking injector return. Watching the scan tool everything seems fine. Injectors look perfect. Fuel pressure is okay while running and cranking. Actual vs desired fine. Duty cycles fine.
Then I noticed my Key on engine off fuel pressure is 42 psi. I thought the engine light was to come on and code set at 52 psi. so I assumed it was my scan tool. Grabbed a different scan tool. LPFP pressure is still 42 psi.
So I am puzzled by that, is that not the case? Shouldn't I have a check engine light?
Next I have read that the LPFP is internally regulated at like 120psi. Logic says I need to dead head the pump to see if it is working and able to achieve 120 psi. If it can pump is likely fine, if not my fuel pump is likely bad and I should start there.
I think I can take the fuel return line off by the filter on the left valve cover, put a hose on it, maybe pinch it to create back pressure? Will that dead head the lpfp? If pressure does not increase, then I have an external leak, leaky injector (which should hydrolock the engine) Or bad LPFP? At this point I would probably get a mechanical fuel pressure gauge and correct fittings to properly test.
If I understand correctly the CP4 has an regulator in it. Mechanical set to 55psi. Also called an overflow valve. This could be bad, or held open by metal shavings allowing fuel to bypass and not build the 55 psi it is set at.
OR Fuel pressure regulator in the Right Rear fuel rail? (not sure this would do it, will it? I need to research some more on this one) Or maybe you guys know how to test this?
Anyway, I think I have tested about all I can test without tearing the top of the engine down. Is there anything else I need to check while it is still running and drivable?
I would imagine my next steps are to tear the engine down. Check the overflow valve and Fuel pressure regulator, as well as pulling the Fuel Volume Control valve on top of the CP4 and checking for metal shavings.
First picture, Key on Engine off.
Second picture, truck running.
Third picture, Key on Engine off
fourth picture Engine running
Fifth picture Engine running.
Does matter if it is hot or cold, sits for a minute or a month.
Cycling the key before cranking does not affect it. Full fuel tank or empty.
No codes ever. Truck has been flawless since new. Put a starter on it and thermostat housing otherwise beyond the EGR DEF issues it has never been touched in it's life.
No additives ever. No bad tanks of fuel, never water in fuel.
Filters changed with motorcraft every 10k since new. been changed numerous times since this condition started.
Batteries have been replaced since this started.
It burns clean, no smoke. No apparent power loss. This last trip my mpg was down to 17.3 instead of the usual 18-18.5 but I also see my intercooler hose off the turbo is leaking pretty bad, so I would imagine a big boost leak like that will affect mileage.
Specs, 2014 F250 186k miles. Deleted with minimaxx but stock fueling. Had this truck for over 6 years now, been doing this for at least a year so last 20-30k miles.
Never had a problem so never had to learn, started reading on a recent 3k mile trip and boy did I learn.
While searching extended cranking I kept coming across CP4 failure as cause. This didn't make sense to me as the condition existed so long how is the truck still running and the only symptom I had was longer cranking.
Here I am into it now. Still no codes. Started thinking injector return. Watching the scan tool everything seems fine. Injectors look perfect. Fuel pressure is okay while running and cranking. Actual vs desired fine. Duty cycles fine.
Then I noticed my Key on engine off fuel pressure is 42 psi. I thought the engine light was to come on and code set at 52 psi. so I assumed it was my scan tool. Grabbed a different scan tool. LPFP pressure is still 42 psi.
So I am puzzled by that, is that not the case? Shouldn't I have a check engine light?
Next I have read that the LPFP is internally regulated at like 120psi. Logic says I need to dead head the pump to see if it is working and able to achieve 120 psi. If it can pump is likely fine, if not my fuel pump is likely bad and I should start there.
I think I can take the fuel return line off by the filter on the left valve cover, put a hose on it, maybe pinch it to create back pressure? Will that dead head the lpfp? If pressure does not increase, then I have an external leak, leaky injector (which should hydrolock the engine) Or bad LPFP? At this point I would probably get a mechanical fuel pressure gauge and correct fittings to properly test.
If I understand correctly the CP4 has an regulator in it. Mechanical set to 55psi. Also called an overflow valve. This could be bad, or held open by metal shavings allowing fuel to bypass and not build the 55 psi it is set at.
OR Fuel pressure regulator in the Right Rear fuel rail? (not sure this would do it, will it? I need to research some more on this one) Or maybe you guys know how to test this?
Anyway, I think I have tested about all I can test without tearing the top of the engine down. Is there anything else I need to check while it is still running and drivable?
I would imagine my next steps are to tear the engine down. Check the overflow valve and Fuel pressure regulator, as well as pulling the Fuel Volume Control valve on top of the CP4 and checking for metal shavings.
First picture, Key on Engine off.
Second picture, truck running.
Third picture, Key on Engine off
fourth picture Engine running
Fifth picture Engine running.