2004 5.4l 3v Failsafe (again) won't start...
 

I have a 2004 Screw Lariat with 82k miles. New cam phasers at 75k, new fuel filter at 70k, Mobil 1 oil/filter changed every 5k.

The Short Story:

- Working on the interior (new carpet, re-dye leather, detailing) this weekend and the battery went dead.

- I also inadvertantly popped the cig lighter fuse when the center control panel (detached) fell off the top of the dash while I was cleaning the areas behind. It fell on a screwdriver in the cup holder and popped the fuse. I have come to learn this also powers the OBD port (changed it and port worked fine)

- Charged it up and started fine as usual. Turned off and restarted again two more times with no issue.

- Ran the engine for about 30 min while I was setting in the back bench seats and then turned it off and went inside.

- Two hours later went to go for a drive and it barely started, rough idled and ultimately stalled. Did that five more times and then the failsafe message appeared. Now it won't start at all and will only crank.

- Let it sit overnight with the battery disconnected and the PCM backup fuse removed to reset computer. No change this AM.

- Read TSB 08-12-2 regarding the re-flash and restored my Ford tune from my Diablo Predator. This updated OEM tune was done about 10 months ago when I had the cam phasers replaced so I assume/hope it was a recent version. The TSB is dated August 21, 2008 so I would think my dealer had it right.

Any suggestions? I haven't had this problem before other than the cam phasers, but I had pinging and knocking back then - this time nothing.

Reading all the threads and I could do one of a dozen things from cleaning the Throttle Body, change the TSP, clean MAF, change Fuel Pump, etc...

Any suggestion from a mechanic out there?

Check the fuel pump driver module above the spare tire for corrosion. This is becoming a high failure item.

Just dropped the tire and it looks pretty darn good. No signs of corrosion on what I'm guessing is the aluminum core and the plastic isn't cracked. Is that corrosion a result of road salts? Down here (Atlanta) we don't have exposure to that problem as much.

Is there a way to put a meter on it to test?

Hey.

Couple things I ain't clear on here. Can you check/confirm:

- It's cranking only even with the stock tune?
- battery voltage Load / No-load?

If yer batt is marginal it *may* cause all sorts of related symptoms.

Flashing a PCM with a marginal battery is playing roulette - just fyi

Perhaps get the battery load tested?

Here's a reference:

http://onsolar.co.uk/blog/wp-content...-condition.jpg

Also - idling is not gonna guarantee charging - the alt may not be outputting sufficiently to ensure a full recharge. A charger / tender is the best way.

No easy way to test the FPDM with a meter - (and they usually throw codes when they fail). Yours is probably okay.

Fuel filter should be changed every 15k / once per year.

I would, as simple PM measures, clean the MAF, TB, etc as a matter of course.

And, it's possible you have a malfunctioning TPS, or Throttle Body - more than a few posts related to failsafe codes and TB faults - it's a more complex system than it appears: http://articles.d-tips.com/art8.html


Good luck!
MGD

I'm unable to view the pictures in the TPS link.

The engine cranks with either the Diabo or the Ford tune. Just doesn't fire.

The battery went dead as a result of having the interior lights on for a full day without starting. It charged and is holding a charge well.

I also keep the charger on while flashing the PCM and set it to "Start Mode" as a precaution.

Changed fuel filter (Motorcraft) - no change.

Cleaned MAF with CRC MAF Cleaner - no change.

Cleaned Throttle Body with Valvoline Throttle Body & Carb Cleaner and it started for a brief second, rough idled and stalled. Back to only turning over with no firing.

Does it sound like the TPS now?

Perhaps.

Just a thought - check the fuel rail pressure? There is a recent thread on this around here somewhere ...

MGD

Shot some starter fluid in the tube - it turns over and starts (sounded like normal) than ran out of fuel I guess. Not sure if the TPS is ruled out, being that the starter fluid is a bit more volatile.

Going to hook up the Diablosport Predator and monitor the fuel pressure tables, if I can figure it out. Any other method to check fuel rail pressure?

Yep. A gauge on the fuel rail Schrader valve.

MGD

On the Diablosport Live Diagnostics I saw that the FPF (Fuel Pump Out Fault Detected) variable would toggle from NO to YES (and ultimately remain at YES). Is there a sensor that is triggering this and where?

I'll have to go to my shop for the pressure guage. The Diablosport has pressure marked as a percentage and not sure if it's correct.

I got some codes after the starting fluid test:

P2100, P2104, P2107, P2110, P2111

Would the security system turn off the fuel pump? I was fiddling with the rear bench and I believe the security control module is behind the bench....

OK - pencils down. Problem solved.

Well after talking with my local Ford parts counter (about to order a fpdm and tps) I was told about the inertia switch. Since I had been detailing the entire interior I must have slapped the passenger side kick panel too hard and triggered the inertia switch, which turns off fuel delivery in the event of a hard impact (accident).

At least I got some PM issues taken care of - I'm sure I'll be back when I do the plugs in a week or so...

Thanks for all the input.