I have a 2016 5.0 that has long cranking after it has been sitting in the sun. I get no codes, no cel, just 5-8 sec of cranking but no fire. It does not do this when cold, but if i am parked in the sun even after 30 -45 min it will take forever to start. If I let it crank a few seconds and then put the key to off, it will start right away the second time as if I needed to prime it. Very odd it is only when it is hot and been sitting in the sun. I understand they took the rail fuel filter away so I could not start with a filter change. Fuel pump is expensive and I think you still drop the tank on the 2016. Should I start there or see if it is more in throttle body or the injectors leaking down, MAF,? Truck only has 59,000 miles.

 

i have this issue from time to time

to me it seems more based on the source of the fuel vs pressure or environment

in MN it happens in hot and cold

the odd thing is if the truck sits for 3-6 hours it will have an extended crank

if the truck sits 8+ hours, it fires right up

if it was fuel pressure it would get worse wit time, its just an odd thing and i have been keeping track of which fuel vendors i notice this problem

Fleet Farm here in MN has a gas station and that fuel seems to eliminate the problem

 

Nothing new. My '88 F-250 acted the same way.

 

Possibly a leaky injector. Do you smell fuel ?

 

if that was the case, wouldnt it get worse with time?

 

I don’t really know. If it’s leaking it could only leak until the pressure was gone. It’s a problem some fords have when you search long start on ford. If you smell fuel then it could be the injector.

 

Leaking until the pressure was gone dosent account for the longer down time being problem free at least in my case and I don’t smell fuel

 

Is the outside temperature reading correct? Is the engine hot or cold? If the computer is getting a cooler than actual reading and the engine is hot it could have the fuel mixture to rich. Essentially flooding the engine with too much fuel. When it's cool and the engine is cold this wouldn't be a problem.

A bad intake air temperature sensor could also cause similar problems.

 

This does not happen when the outside air temp is cool, or when then engine is generally cool. This happens when the outside air is very warm and the truck has been sitting in the sun. Is the air intake sensor in the air duct by the filter? I was thinking about changing that or the least expensive. Then maybe go to the pressure in the rail line.

I had read that the new fuel pump set up in the tank has an integral filter and check valve that could be going bad and thats causing the leak down in pressure. I thought about the injector leak down as well. No signs of poor performance or fuel mileage, just that hard starts in the direct sun.

 

Following. It’s been happening on mine since about 50k miles. I’ve had electrical checked and no codes.

It happens regardless of outside temp if temp if it sits 2-6 hours. No issues first thing in the morning. I have another thread going where somebody reported a couple treatments of sea foam helped, but I’m not so lucky (yet).

I have 2015 v8