2002 XLS 4.0 4x4 Cranks but not start...

[jcsaathoff]

Hello I have a 2002 Ford Explorer XLS 4 door model with a 4.0 L V6. Since November I have had problems starting the truck. It takes several cranks to start the truck, some times 5-10 mins worth. It has always acted like it does not get fuel. Once it was started it drove fine, and if the engine was still warm it would start right up. It takes a couple hours sitting to "recreate this condition". I took it into the shop to have it fixed and they installed 2 new pumps within 2 weeks, obviously this did not solve the problem. They claim they have no idea whats wrong with it, and they say it started up fine all day today and they have done nothing since installing the second fuel pump. I'm not aware of it throwing any codes.. the check engine light has never come on.. I did the other day watch them try and fix it up when I went to pick it up... key would turn on and it would be 0 psi... 2nd time 30 psi.. no start... 3 time 10 psi no start...
They made mention that there was a TSB out concerning re-flashing the computer for a cold start issue... but they said this would not cause the fluctuation/lack of pressure in the fuel system. They say they tested the Fuel pump relay's and the inertia switch and they were fine?? It seems almost like a thermal problem sometimes (hot engine/cold enigne) but I've parked it in a heated garage and had the problem recreated and its been outside in 40 degree weather and started right up... Also I've had this for 2 previous winters and ALWAYS started up.. until this one...

 

[Vargas]

Bad fuel pressure regulator?

 

[jcsaathoff]

dunno.... but I would think if it was the regulator wouldn't it cause a problem when it was running? I dunno just asking.... lol

sorry for showing my ignorance here.. but I'm used to mechanical F/P that you could change for $15 bucks an 20 min worth of time....

I dont know how this 2 speed electric pump works... is it in a different speed during start up? if so what triggers the 2nd speed? is there a sensor? separate circuit/relay?

 

[Vargas]

Really only a few things that cause widely fluctuating fuel pressure

1. Bad pump, unlikely since it has been changed
2. Bad regulator
3. Unreliable flow from tank pickup - either low fuel level, tank damage, or debris in tank blocking pickup.

 

[Swoll]

Did you ever fix this problem? I have the same symptoms. For the 2002 Sport Trac 4.0, the fuel pressure regulator is built into the fuel pump correct? I dont want to replace the fuel pump if it is not the problem.

 

[jcsaathoff]

Yes.. er I think... lol
At the end of last winter I replaced the fuel pump relay, but after that it never really got cold enough to reproduce the problem. Over the summer I used a bottle or two of Lucas fuel treatment and replaced the Ignition switch (the actual electrical part of the switch), thinking the contacts might have bad/wore out inside of the switch.

Now I know there are probably people out there that wont agree with it and it sounds really silly.. but the new switch was a lot more "positive" with its clicks than the old switch.. metal shrinks when cooled expands when hot and copper is pretty sensitive to temp change, so the worn mechanics of the switch plus the cold shrinking of the contacts, gave it enough to have issues when it was cold?? All I know is it works now and I didn't spend another $800 replacing the fuel regulator and I would have thought they have checked the cleanliness of the tank after the put in the first fuel pump, if not, when the put in the second. It cost around $60 and took about 10 minutes to replace.

I don't think it was the relay.. they said the tested it and it was "fine", but me being me I got a new one for my own warm and fuzzy feeling and opened up the old one... the contact inside did look ok.. but it does have a lot of copper in it also. Like I said sounds dumb but my experience is its the dumb things that get over looked.

Let me know what ya find I would be interested in hearing what was the cause.. Good Luck!