The truck (2006 f150 5.4) has just over 300k mi on it. My son drives it to school and work. The truck started shutting off while sitting at the red light or turning into the parking lot. Had the truck towed home and it would only crank and not start. Yesterday it started normal in my driveway, I didn't drive it just shut it off after about 5minutes of idling. Later on went to start it up and it just cranks so I changed the fuel pump driver module which was corroded still no start. In the process of removing the spare tire, the black plastic head of my key broke off exposing all metal. The spare tire lock was seized even with wd/40 i wasn't able to remove it without the help of pliers. Now after changing the FPDM its not even cranking anymore just clicking at fuse kick panel. I did notice that when I turn the key (now broken) to start the anti-theft light flashes rapidly. Any Help would be appreciated. I will continue to troubleshoot.

 

The anti theft chip that's in the key is housed in the plastic part, so it's not going to start as you describe with the PATS light going bonkers.

You'll need to resolve that hopefully you have a spare key, or if you have the plastic pieces that broke off you can probably take the old key and the plastic to a locksmith where they can make a copy of the key and clone the old chip. Or glue your old key back together for now, etc.

Once you resolve the key situation if it's still not starting then you'll have to troubleshoot more. You can try to spray stating fluid into the air filter housing and see if it briefly starts that will tell you if you have spark or not.

Seems like there have been a rash of folks lately reporting stalling with no other symptoms or codes that was due to the crank position sensor or it's wiring being the culprit, as the engine just cuts off if it doesn't have that signal to know when to fire injectors or ignition.

 

^^^ this

- when trying the starting fluid, remove your intake tubing so you can spray straight into TB

- as stated, if it pops, you’ve confirmed sparky, but also a fuel delivery issue if it does t pop

- note: a failing crank sensor can be intermittent (sometime only failing after use, and sometime only under certain other conditions, such as rapid decrease in rpms. Often all without codes)

 

Okay the spare key is lost, but I was able to glue the plastic piece back on. I added a few wraps of duct tape also to reinforce the key.

Truck started right away, no rapidly flashing theft light. gluing the plastic piece back on the key was the solution to that problem along with getting another set cut and reprogrammed by a locksmith.

There still is an issue with the truck stalling and the miles to empty gauge. I haven't drove it yet because my son isn't home to follow me, and I don't want to get it stranded.

After the truck had warmed about 5minutes into idle it had only one noticeable stall almost like it was about to die but it didn't, and it was running normally since.

The miles to empty gauge were going bonkers the entire time. It was almost giving me a 30+- mile difference the entire time. The gauge went from 171mi to 160mi within one minute. When I shut the truck off the gauge was at 180miles to empty. Everything else run normally. No codes or lights just the gauge and the stalling.

Thanks for the help.

 

wouod be great if you could monitor fuel pressure when stalls. Assuming that isn’t possible, have your starting fluid (and tool to air tubing) ready, then try to drive it to get it to stall. Then while it still won’t start, try the starting fluid test. That should give you good info.

 

I have a 7 inch touchscreen full Android radio running Torque Pro. Fuel pressure is one of the PIDs I monitor. It's pretty neat to be able to do that or I am easily amused.

 

See below

 

Update:
After replacing the fuel pump driver module and cleaning the ground connections. The truck ran well for a few weeks but then started stalling at red lights and not cranking again.

Another issue discovered was the water pump was leaking. Replaced the water pump and started troubleshooting the no start crank/stalling problem.

Used forscan and laptop to check fuel pressure whenever the truck wouldn’t start. Fuel pressure reading was 39psi to injectors IIrc. Used starting fluid sprayed into intake, truck started right up and continued to run with no problem. This ruled out the fuel delivery issue verified several times with forscan.

Pivoted to replacing the crank sensor between A/C compressor the truck hasn’t stalled or had no start condition since. It runs even quieter now probably due to water pump replacement but it was the crank sensor that fixed the issue. Son is happy to be back driving it to school!

Thanks for all the help and great suggestions which led to the fix! Wanted to update.

ETA: Forgot to mention the TB and MAF was cleaned using tb and Maf cleaner but the truck still stalled or wouldn’t start.[/QUOTE]

 

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really glad you sorted it out and thanks for posting the resolution(s). Perhaps you could clarify one thing, that doesn’t seem to make sense to me (as written at least). The part I highlighted. The fuel pressure during no start does appear to point away from a fuel problem. But then you said that (also during a no start) spraying starter fluid did make it start right up… this would appear to verify a fuel problem, NOT rule it out. Can you clarify this part?

 

Yes the starter fluid did get the truck back running again whenever it would stall. For example I would drive it to store and whenever I finished shopping the truck would not start just crank. I sprayed starting fluid into the intake and it would start and stay running until I made home.

Another time I dove to my mom’s house which takes about 30mins and the truck ran excellent, after visiting for a few hours I got into the truck tried to start it and nothing just cranking. So I sprayed the starter fluid inside the intake and it started and I made it halfway home when the truck stalled at a red light. I popped the hood sprayed the starter fluid inside the intake and It started right up. I was able to get home.

While home I tested this method. Before installing the crank sensor. I used forscan to help monitor the fuel pump faults, pressure, and voltage.

After warming truck at idle possibly about 20mins I shut it off and let it cool. I waited about an hour before trying to start the truck to simulate the conditions and time intervals. It didn’t start only cranked.

Plugged in forscan to check fuel pressure, pump voltage and fault codes and the levels were the same as when the truck started still no start. I would toggle the key from koeo to run and forscan would give the reading in realtime. I did this both when the truck would start and when it just cranked and got the same readings with no faults.

After using forscan and getting those readings I concluded the crank sensor was suspect thanks to this forum. Yes I sprayed starter fluid into the intake even when there was fuel at the rail. It didn’t take much to get it started at all maybe 1/2 second burst and the truck would start.

Sorry it’s been over a month for the reply. Truck is still running strong and smoothly. Son really appreciates it, he would get worried about getting stranded at school. No more big thanks for helping us out. Hopefully it answers your questions.