Just went over 150k today. Over the past 20 days my truck has had trouble starting. Not all the time but sometimes it will fail to start but eventually it will start after continued attempts. Below is a list of things I've done but the issue continues to happen. There is no code being thrown.

Replaced battery and spark plugs(old battery was only 18 months old and is still good)
Changed oil even though it still had another 2k before service
Load tested the alternator, no issues
Checked all the fuel injectors (fuel was spraying evenly)
Went through and checked nearly all ground connections
Put dielectric grease on the COPs to the plugs and their connectors, put it on the fuel injector connectors as well
Cleaned the air filter, checked all fluids all good
Currently running a tank of 93 octane with Lucas fuel treatment, about halfway through that

The best way I can describe it is that it is strong push on the engine but it just won't start. Need fuel, air and spark to start and I've covered all that. I have not taken the starter off to check it's teeth yet but It's not making a drilling noise, I can feel a strong engage from starter. When the engine is running you can hear the rocker arms clicking but I think that is normal for the 4.6 right?

I baby this truck and it is very clean for being nearly 10 years old, I've done almost all the recommended services myself since I bought it 5 years ago.

***Edit: It's not the key, it does it with OEM one as well***Another thing that I don't know if it would affect this is I recently had a new key made at my local Ace Hardware about 60 days ago because we lost one along the way and the other original key is broken at the ring holder. Could a bad chip in the key cause this? I don't even know if the key has a chip, seems like an old fashion key to me with a thick plastic head but the Ace employee swore up and down it has a chip in it.

Anyone have any suggestions or ideas? TIA!!

 

Yes, it has a chip on it. It might be a bad key. But I would think the anti-theft system would be saying something.

 

So I debunked my key theory today, it did it with the original Ford key as well.

I'm thinking maybe fuel pump? Is that the big black box under the drive side that has all the fuel lines running to/through it?

 

No, the fuel pump is inside the fuel tank.

Check the FPDM for corrosion on the back side and connector. It's located on the crossmember above the spare tire.

 

 

I will do this tomorrow.

If you're talking about leaking around the o-rings where the the nozzles connect to the rail or are inserted then no, there is no leaks.If you're talking about the flooding of the engine from the tip of the fuel injector then I do not know. The rails and nozzles are very clean. The truck has no issues while running.

 

So the FPDM is defintely not above the spare tire. There is nothing above it.... This is a 2010, not my 2001. There is a big black box where all the fuel lines run in and out of on the driver's side frame.....

 

Pcm power relay?

 

FPDM:

https://www.f150forum.com/f4/fuel-pu...8/#post4051791

They changed it in 2009.

 

Ok, so I didn't see this. It was not rusted at all, I took the clip off(it broke) and put dielectric grease all over the female end. It hasn't happened in the past two days so we will see.