1999 Expedition EB 5.4L Stalls / No Starts SOLVED

[juan214]

So yesterday backing up very slowly and truck stalled with no warning. Started right up. Got to my destination parked and idled stalled out again did start this time. Waited a few minutes it started and ran fine. Got to my next destination same thing. No problem on third destination. Fourth ae idle rumble / vibration left there. proceeded home truck stalled while driving coasted down the street turned a corner coasted down that one. Restarted in neutral start made it home. Pulled in driveway starts fine. I did notice a couple of weeks back while highway speeds between 60 - 70 like there was surge / miss. Other than that it runs fine. No CEL, put my scanner on it no codes or stored codes. Everything looked fine on it. Anyone got any ideas what to look for?

 

[stamp11127]

Check fuel pressure with a fuel pressure gauge the next time it stalls.

 

[docraymund]

Replace fuel filter.

 

[Big Brian]

I had an Explorer that acted that acted similar. It ended up being the fuel pump relay was getting weak. I swapped it with the high beam relay (which was the exact same relay) and the problem was solved.

Not saying the other suggestions aren't good, but something else to check and its very simple

 

[juan214]

Thanks Rich got a tester will do that later today
Thanks Ray change about two years less than 20K ago
Thanks Bri was going to look and test the relay as well

Thanks all, Its starting now lets see what happens will get back on here later today

 

[stamp11127]

Fuel pressure needs to be around 40- 45 psi for normal . Test with keof and while running. With key off pressure should not bleed off. It will run with lower pressures but not as well as it should, usually they die @24 psi.
If it is determined to be a fuel problem, jump the fuel pump relay and repeat the same pressure tests.

 

[juan214]

Key on cycle 38 psi drops 35 psi
Engine Running / idle 30 psi
Engine rev 2k +/- 2-5 psi
Engine off 38 psi

Test Drive:
At 20 mph 32 psi / 30 psi stopped (idle)

9/24/15 11K ago
Fuel Filter K&N PF-2000
8 Super Ignition Coils High Energy Coils
8 MOTORCRAFT SP479 SPARK PLUG (AGSF22WM)
8 Bosch Flow Matched 4 Hole Injectors

4/15/12
Fuel Pump replaced

 

[stamp11127]

Pressure is within spec but right on the lower limit. Next time it acts up read the pressure again without cycling the ignition key.

 

[juan214]

Had to restart test forgot to read it.

Bleed Off Test:
Start 2.50pm 38PSI
3:00pm 25PSI
End 3:10pm 10psi

 

[juan214]

No Start Condition (while parked / not stalled during driving):
Theft light goes out with every start attempt.

Beginning PSI 10 psi

3:10pm :
Key on 38 psi drops to 35 psi
Crank 35 psi (constant)
Restart 35 psi - fail start
Restart 35 psi - fail start

3:15pm
Key on 38 psi drops to 35 psi
Crank 35 psi (constant)
Restart 35 psi - fail start
Restart 35 psi - fail start

3:20pm
Key on 38 psi drops to 35 psi
Crank 35 psi (constant)
Restart 35 psi - fail start
Restart 35 psi - fail start

3:25pm
New dealer cut and married key (purchased and programed 11/18/15)
Key on 38 psi drops to 35 psi
Crank 35 psi (constant)
Restart 35 psi - fail start
Restart 35 psi - fail start

Usually after 20 minutes it restarts. Banging on tank does nothing and I'm sure it shows pressure it may not be the pump.

 

[juan214]

As usual it started after 20 minutes (for 3 days now)
Daily key and New dealer cut and married key (purchased and programed 11/18/15)
Key on cycle 38 psi drops 35 psi
Engine Running / idle 30 psi
Engine off 38 psi

runs now................................

 

[Big Brian]

did you try swapping relays like I suggested?

 

[stamp11127]

I like the way you organized post #10 although did each restart pass or fail? Please update accordingly.
You have almost eliminated a fuel issue.

When the fuel pump was replaced - who did it? If it was you, did you use a new hose between the pump and line out, clamps also - new / good and tight? Or did you grab an assembly from a wreck?

Big Brian - his pressure readings indicate the relay is working by powering the fuel pump. He should see how warm the relay is when it doesn't start to eliminate low voltage to the pump (resistance causes heat).

Juan, do you have any of the old ignition coils and a spark plug? If you do then the next time it doesn't start swap it in for one cylinders with the plug threads laying on the block. Have someone watch the plug for spark while cranking. This is basically a redneck timing light. I would recommend not holding the plug while cranking.

 

[Big Brian]

I understand that

if it an intermittent problem like it sounds to me like it is, he may not be seeing it with the fuel pressure if the relay is behaving itself when he is checking fuel pressure. The relay problem I had acted exactly like this. It would just act up then act normally. Swapping it with another relay is very simple and swapping it would rule it out if it didnt fix it.

 

[juan214]

Relay swapped out original was DEI. Put in a Ford relay no start, swapped that one for another ford relay no start Then finally swapped it with one from the Junction box no start. After 20 minutes truck starts

 

[juan214]

Post #10 all failed starts

 

[Big Brian]

Relay swapped out original was DEI. Put in a Ford relay no start, swapped that one for another ford relay no start Then finally swapped it with one from the Junction box no start. After 20 minutes truck starts

ok I saw no mention of this

I will go away now

 

[stamp11127]

Now we start looking at pcm electrical - specifically heat soak.
Easiest is to swap the pcm relay with another of the same or higher rating. When you pull the relay check for discoloration at the base where the pins come out.

 

[stamp11127]

Big Brian stay and add additional thoughts.... this is just a big puzzle

 

[Big Brian]

I know I said I was going away but if it was in my shop I would be checking for spark.