1998 Expy Will Not Start

[PVExpedition]

Hi,
I have a 1998 Expy with 275,000 miles, 4x4, 4.6l, W engine.

I have had this Expy for 7 years since it had about 150k on it. It is serviced by a professional mechanic whenever needed and it is in great shape, and runs like new.
2 weeks ago it would not start. It cranked and cranked but would not start. It had a full tank although 3 days earlier I had let the low fuel light come on. It finally started after about 30 minutes when I just barely depressed the gas pedal, as per a friend suggested. I don't think the gas pedal had anything to do with it as it is fuel injected and not carbuerated but...whatever, it started.
This Expy starts the moment you trun the key..it never cranks over & over, put the key in, turn it, and vroom..fires ASAP. It has done this since the day we bought it, except when the fuel pump went out driving down the freeway 4 years ago.
So, I am away on business and do not have access to my regular mechanic. The new mechanic I am going to is good, and suggested we try small and change the fuel filter since I had let it go to a low fuel level. We did that, and it has been working ok since. Occasionally it cranks 2 - 3 times but then it starts. More often than not turn the key and it starts ASAP like normal. Until this morning. Crank & crank & crank..no start

This new mechanic is not available so I am stuck.

Any thoughts?
It runs fine when it does start.

Fuel filter replaced 1 week ago
Fuel pump replaced 4 years ago, about 35,000 miles ago
Battery is 1 year old
serviced regularly
EGR sensor replaced 1 month ago
check engine light is not on...it was, but it goes out, not on now, check engine light is often on on this Expy

Can a crank sensor be intermittent when it is going out? I think this may be the issue.

Does this 98 Expy have a crank sensor AND a cam sensor, or just the crank sensor?
Where is the crank sensor located on this 1998 4.6 Expy? Easy to change? Do I need to worry about TDC? If so, how do I get it to TDC without a timing light, etc? Disconnect the battery when changing the crank sensor?

Thanks for the help.

 

[toms89]

The crank sensor is located near the crank pulley (harmonic dampener) on the passenger side.

Any electrical issues can be intermittent in nature.

It has both a crank and cam sensor but it has been determined via another post it can run with the cam sensor not working?! The crank sensor tells the pcm the relative position of the crankshaft obviously but you need a cam sensor to tell the pcm if its power stroke vs exhaust. Crankshaft spins twice for every revolution of the cams.

No start can be caused by many things. Need to read the stored DTC's. This may lead you in the right direction.


If you replace the crank sensor there is no concern on engine relative position. It can only go in one way. The reluctor wheel is inside the timing cover and cannot go bad short of physical damage.

 

[PVExpedition]

1st,
how much does it cost to get to this site without the stupid ads? Those ads tie this laptop up like you would not believe.

Ok, I had the mechanic change the crank sensor even though it tested fine at the day time temp, whatever it was today. But, when he put it in the freezer it failed. It also failed after he boiled it.

He also found a third wire (bare) in the wiring harness that he believes Ford put there to make the harness stiffer. He found that wire had rubbed the two electrical wires raw and they were shorting out with each other.

I am hoping this is the issue and next week I am doing new plugs and wires on it. It should last another 25k or so.