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After Fueling (?) 2000 Ex 7.3L won't start

Low fuel light was on for about 20 miles. Yea, I know I’m an idiot, but I’m a broke idiot as well.

I made a few stops before fueling, and it started right up as usual. The first time I stopped it after fueling, was when the “fun” began.

Put in key, turn to start, all normal dash lights come on, theft light is blinking normally (slow), and nothing, not cranking… Can hear some clicking from the drivers side, engine compartment, firewall fusebox, and a brief whirring (motor sound) from in front of the drivers side battery (is that where the fuel pump is?).

Electrical is okay as far as I can tell, but fuel pump is not doing it’s normal ~30 second pre start pump.

Opened fuel filter can, and it was full. I then drained it.

1. Disconnected the negative cables (hoping for a reboot), and cleaned them up, to no avail…

2.Tried the fuel shutoff switch on passenger side, to no avail…

3.Tried two different, newer sets of ignition keys, to no avail…

What is my next plan of attack?

Thank you,

Quit playing with the keys and computer before you tear something up.

There are 3 things a diesel has to have to run: Fuel, Air, and Compression. Since you didn’t blow your engine up and I assume you didn’t throw a flat board into the intake, I’ll assume you have air and Compression. What you don’t have is fuel.

Here’s why.

Diesels are nothing like their gasoline step cousins. Gasoline fuel systems are not under near the pressure that a diesel is and while air in a gas system might cause a spit and sputter till it clears, air in a diesel fuel system will kill the engine dead.

You said you took the fuel filter cap off, then opened the water valve and drained it. Did you fill it back up before putting the cap back on?

Anytime you take that fuel filter cap off you should before reinstalling the cap turn the key on and let the electric tank pump fill up the bowl to the point that the fuel flows over the top slightly. I like to fill it real close, then put the cap on about 3 or 4 turns, then turn it on again and let it overflow just a bit, then tighten the cap on it. You don’t want air to get into that system if you can help it.

The Navistar engine in that truck uses Caterpillar’s HUII injector system. Fuel is fed through ports in the heads to the injectors and the injectors are powered by high pressure oil and solenoids that release the plunger. If you get air in the heads, you’ve got a problem.

There are 2 bleeders, one for each head. They are in the very back of the head and look like drain plugs. You loosen them by turning them with the end of a 1/4 inch ratchet. Ideally, you would back them off about 3 or 4 turns not all the way out, keep turning the key off and on to activate the electric pump. When fuel starts to flow out of the plugs you’ve got about all the air you can get out of the heads. These things are hard to reach. You can probably get to the passenger side one from the top of the engine, and you may have to crawl under and reach up for the driver’s side one. You won’t be able to see them, you’ll have to do it by feel as they are pretty much close to the firewall.

The next thing you’ll need to do is make sure your batteries are both fully charged and keep a charger ready. If you have one with a 40 amp or even better 100 amp booster mode, it would be nice because you are going to have to crank the heck out of it to get it started.

Once the batteries are ready (leave charger going if you have one with the booster mode) crank the engine. Be careful, do not crank it more than 60 seconds at a time letting the starter cool between cranks about 2 minutes. As you crank it, the engine does automatically purge air. You may have to crank on it for 15 or 20 minutes, maybe more You should hold the fuel pedal flat on the floor. That’s why you need full batteries and may even have to charge the batteries in the process and try it again. When it starts, it will sound like it’s coming apart and white smoke will pour out of it. It will be missing on some of it’s cylinders, rattling, banging, and carrying on. As soon as it starts, let off the pedal and let it set there and rattle and bang until it smooths out. As soon as it smooths out, hit the highway with it and run it at 50 or 60 mph for about 30 minutes to purge the rest of the air. Don’t be surprised if this process takes a recharge or 2 and takes all day. Some people will tell you to give it a shot of either, I’m not a big fan of that with the Navistars and neither is Ford or International, I’d try to avoid it.

You do stand a good chance of burning your starter up if you aren’t careful with it. After you go through this once, you’ll not let it run out of fuel again. If you have to have a shop do it for you, it’s obviously going to be fairly expensive.


Skipper gave you a lot of great advice. Pay attention to him and maybe you can save a few dollars, pounds or whatever. Let me stress the part about not just trying to start it. That is not so bad on a gasser, but a diesel can get a little funny about that. My guess is you have an air block in the fuel system (Never run it dry).

Is everybody on the same page? You said that you tried to start it and, “…nothing, not cranking…can hear some clicking”.
Why didn’t you get a jump start to crank the engine? Why all the other things not concerned with cranking the engine (making it “turn over”)?
“Clicking” is, usually, the starter solenoid not getting enough voltage, Low voltage can be from low battery(s) voltage, and/or a poor electrical connection somewhere in the START electrical circuit.

Man, if that’s the case, I’m sorry, my out of fuel procedure doesn’t apply.

If it is not cranking the engine: The starter is not engaging and turning the engine over:

First of all, jump starting one of these things is extremely tough. You’d have to have a set of welder cable jumper cables to be able to get enough amps from the other vehicle, and understand, your diesel uses two batteries to start itself. Each one is around 900 CCA which is a lot larger than anything in any gas vehicle. You can roll one off if it’s a standard shift, but otherwise, you are well advised to charge your batteries back up if that’s the problem.

Some things to check right off:

  1. Oil Level: Navistar engines like this require plenty of oil to run. The 7.3’s hold the better part of 4 gallons of oil. The dipstick doesn’t register to add unless it is at least 2 quarts low. If your oil gets below 1 gallon (I believe, that’s correct) a safety switch shuts off the starter and it won’t start.

  2. Crawl under it and check the cable to the starter to see if it appears tight. These trucks require a lot of amps to start them and it’s not uncommon for the power over time to become loose or burned.

  3. You could have a starter solenoid that went bad. On mine, it was on the passenger side fender. You can take a large screwdriver with a good handle on it and cross the 2 large bolts, the starter should turn over regardless of the key position. If it’s still not turning over it could be that the starter is dead. When you jump the solenoid, the starter should move or else.

If the starter is turning the engine over, judging by what you did to the fuel filter, I suspect you air locked it and that’s why it’s not starting


I’m curious if you got this truck running.

One thing that can happen if you drylocked the filter is there is a fuel bowl heater element in that could possibly short out. If it does, it has a fuse for it in the long fuse box under the hood. It’s one of the odd big fuses that costs $6 or $7 each. If it did short out, it can melt in the bowl and have to be removed and replaced. Most places would probably just replace the entire fuel bowl at about $400 because it’s a witch to get a melted heater out of the bowl, but it can be cleaned out and replaced. The element is probably $100 or so, maybe cheaper if you buy it from the Navistar place instead of Ford.

The filter bowl shouldn’t need to be completely drained ever. The drain lever is a water drain. It’s purpose is to drain off water from the water separator. You should do that ever 2nd to 3rd tank of fuel. It only takes a couple seconds, there shouldn’t be that much water in there. When you do drain it always cycle the key twice without starting to pump the fuel back up.


I can start the Ex by jumping the large terminals on the Fenderwall solenoid, so I bought a new Motorcraft solenoid, and installed it, but it still does the same " no start" thing??? I can also jump the terminals in the new one (Hecho en Mexico).

The electrical circuit is incomplete from the ignition switch to the starter solenoid. It could be any switch from the fuse, to the ignition switch, to the neutral safety switch. Why not let a mechanic, with a voltmeter, figure it out. It’d be cheaper than throwing every switch at it.

Battery to small post does start the Ex as well.

Circuit between the small post, and solenoid mounting bracket is good.

This is a 2000 model. Does it have a chip key or plain key? The reason I ask is Ford’s ignition switches aren’t the best in the world and they do go out from time to time, particularly on the diesels because there are 2 high current positions Glow plugs and starter. Have you noticed the switch acting funny or the key difficult to remove at times or lots of play in the key? Does the key seem sloppy like it can turn a little in the switch without moving the switch ring? Common problem on these trucks is the users have a big ring of keys to open everything under 4 sons. The extra weight bouncing in the ignition really wears on the switch. I’ve had 2 of these go out in Fords.

A standard key switch is pretty simple to change. You’ll need a long finish nail and your key. Turn the switch to off with the key in it. Underneath on the steering column is a hole that goes up into the middle of the key switch about 1/2" in from the keyswitch face. Shove the nail up in the hole and there’s a catch in there that it will release. Simply pull it straight out. Get a new switch from Ford, the last one I bought was around $60 and I changed it in the parking lot, it’s that easy.

As far as your key goes, the original key fits both the door and the ignition. A Ford key works with the bottom portion of the key operating the ignition and the top portion operating the door lock. The new switch will come with a new key only cut on the bottom. If you can find a local hardware store with a guy willing to tinker with keys, you can very carefully cut only the door portion into a key for the new ignition. Piece of advice, don’t try it on the original that comes with the new switch in case of screw up. If you have the original key numbers (those metal things that were on the keys when you bought it) the dealer can fix the door part to the new key as well.

If it’s a chip key, I’m not sure if that will work, ask a trusted dealer mechanic. Likely they’ll have some sort of thing to program the key. No doubt over priced and expensive, but part of it I guess. I kind of wish they’d quit putting that garbage on a vehicle.

The alternative might be to rig up a push button starter switch in the cab if that doesn’t work. I’ve heard of people having to pay a few thousand bucks for a new something or other to fix a lost key. I believe I’d find a new way to start it. It shouldn’t be much of a problem to rig it up. The concern would be glow plugs. Can you switch still activate the glow plugs? There are 2 systems that run the glow plugs, mine was ran by a solenoid exactly like the starter solenoid. It’s in the area of the fuel filter bowl. It would be pretty simple to rig a wire to it to activate them manually (I kind of wish they’d do that anyway, make it like a tractor that way you don’t have to wait on them in the middle of the summer after it’s ran half a day)

I won’t swear to it 100%, but I believe the antitheft mechanism on these rigs shuts off the injectors as opposed to blocking the starter. I can’t hardly believe a faulty key would prevent it from cranking over. If there is an ignition fuse it would be one of those large $7 fuses that’s in the box under the hood. On mine it was on the driver’s side above the fender well. These are the 40 and 50 amp fuses, the ones in the under dash box would be too small.


Bought the thing in January 2008, and the ignition keyway is a bit sloppy. Don’t know how many keys the previous owner had hangin’, but I’ve probably got more than I should.

It has a chip key, but no door cut.

The Ex has the number pad door entry.

I will check through the fuse box in the AM.

Thanks much for the guidance,

Are you sure there’s not a backup door lock that opens with a key? There should be. What happens if the battery is dead and you can’t use the push button thing? My last Ford had a key lock on the driver’s door but none on the passenger door. That key probably opens the glove box too. It’s kind of a minor inconvenience, you could always keep both keys, the original to lock the glove box and open door, but just mentioned there’s a way to fix that where you only need the 1 key. If you bought it used and didn’t get the number tags off the original keys, you’ll have to use the tinkering method most likely.

Confirming there’s slop in that key switch would make it suspect in my book having experience with those. I’ll say this, it is best to change it before it goes completely out. If you wait till it goes completely out and you can’t turn it to the right position to make it release the alternative is drilling it out. Basically it turns a 5 minute job into a 2 or 3 hour much more expensive job. With the age of that truck, it’s likely about time. On my 94 F150 I changed the switch in 2000 or 2001, then on my 96 I had to change it around 2002. Actually, I changed it the day I bought it used. The previous owner was having trouble with it and it went squirrely on me when I went to test drive the truck. It seems like It stuck in the wrong positon and like you described a bunch of lights came on in the dash.


Duh!! Yeah, (my bad) there is a door lock on both front doors.

Checked fuse #20, and assorted others that may be related to starting, and all were fine.

Tried starting it this afternoon after checking the fuses, and it started two times each in Park, and Neutral. Then went back to being “dead”.

Then I checked the transmission range sensor. Unplugged it, and all connections/pins were clean. Gave the sensor a few taps with a flashlight while under Ex, and gave it another try. It started about six consecutive times in Park, and Neutral, never once shot a blank.

I miss understood I thought you were saying the only way in was the keypad. I don’t remember if it was my 04 F250 or my wife’s Expedition, but one of them only had 1 key door. I guess Ford was saving a few cents on key locks. I was thinking that they might have saved double on yours. :slight_smile: What I was saying on the key is, if you look at the cut part that’s about an inch long on the key, the first approximately 1/2 inch from the tip up works the ignition, the second half in works the door.

The more you are describing it the more it sounds like the key switch to me. That’s the way they act when they get too worn to work right. For whatever reason, the worn switch hits on the wrong contacts in there and the right thing may happen and it may not. I’d urge changing it before it locks in one position or another and has to be drilled to remove it. I think if you take both original keys to the dealer, they can program the new key’s chips. The new keys will be the expensive part of it. Dodge charged me almost $70 for a new programable key.


Glad that you found that the neutral safety switch was, seemingly, the problem. Sometimes, these things don’t stay “fixed”. I’m sure that you’ll keep the Range Selector Switch (aka neutral safety switch) at the top of your “suspects” list should the problem recur.
It would be a good idea to keep the ignition switch on that “suspects” list, too.

I gotta start reading his posts a little better the first time.

The transmission range sensor? (I assume an Excursion is similar to a truck in that it has high and low range 4wd) What would that have to do with it starting or not? They’ll start in low range, high range or 2wd.

I’ll admit, I don’t know a whole lot about these rigs with auto trannys. All the ones I’ve ever dealt with were manual shift trucks. I did the call a friend thing. A buddy of mine used to be the head diesel mechanic at a large Ford dealership. He’s now at a Chevy dealer, but he knows 7.3’s inside out.

The Neutral safety switch is a black electrical deal near where the shift linkage (cable) comes into the tranny. That’s going to be your cheapest fix. Try a new one. If that doesn’t work, he agreed with me on the key switch.

I asked him what sort of rigamarole you have to go through on these chip keys. He said that it was a dealer only change. They have to hook it to Ford’s computer and reprogram the truck for the new key. He’s been at Chevrolet a while, and they may have added a machine since then to program the key to the truck external to programming the truck to the key. Either way, I guess they’ve basically figured out how to make a $50 problem into a $500 problem. Neutral safety switch is probably under $100, so if it was me, I would probably try that first and see if it worked. I’d ask how much they would charge to change out the key switch, if more than $500, If it were mine, I’d be putting momentary switches in the dash for the glowplugs and starter.


The Drama Continues:

So, before getting a chance to change out the transmission range sensor, I try to start the Ex the next morning. It tries to crank, but sounds like it’s low on battery power, and eventually gives up trying.

Since that fiasco, every time I turn the key forward to the start position the dash lights are dim, and flicker, and the power doors, and power windows do not work. When I turn the key backwards to the ACC position, the power windows, and power door locks work fine.

I double checked the batteries individually, and they are both 13v or more.

I have since taken apart the steering column cover, and unbolted the ignition switch from the column. When I move the ignition switch “lever” forward, I get the same reaction as when moving the key forward; Dim, flickering lights, no power, etc…

Is there a way to check the switch, or do I just replace it for $30.00?

Not that I know of.

Since that fiasco, every time I turn the key forward to the start position the dash lights are dim, and flicker, and the power doors, and power windows do not work. When I turn the key backwards to the ACC position, the power windows, and power door locks work fine.

That’s all symptoms of the switch being bad and not hitting the right contacts.

I have since taken apart the steering column cover, and unbolted the ignition switch from the column. When I move the ignition switch “lever” forward, I get the same reaction as when moving the key forward; Dim, flickering lights, no power, etc…

I’m not sure how the levers work in there. I’ve never taken the column apart to change a switch. That doesn’t sound right though.

On a diesel, if you checked the voltage individually, did you unhook the cables when you checked it? They are in parallel so they should read the same voltage regardless of if one is bad or not.

There is something a faulty switch could screw up, that is the glow plug controller. My 7.3 was the older non intercooled version that was exactly a T444 Navistar engine. Yours is likely the newer intercooled version. On it, Ford redesigned the upper end and it’s not an exact Navistar engine as far as some of the controls on the top go. The glow plug controller on mine was a simple solenoid that was connected to an atmospheric switch that regulates the length of time they are on based on temperature. Some of the newer versions have a more sophisticated (Read, more expensive) glowplug controller. There is a possibility it could be messed up, but you have to get the switch working on the right positions first.

The only 2 things that can draw enough amps to pull the power back are the glowplugs and starter. I would get the switch changed and hope nothing else is messed up.

Glowplugs on these engines aren’t easy to change. They are located under the valve covers so you have to remove both valve covers. The plugs aren’t much, about $12 each and pretty easy to install once you get the covers off. I do advise that if you go to the trouble to do it, you go ahead and replace the valve cover gaskets as they have a reputation of shorting out in the harness that passes through them. The gaskets are about $70 each for yours. The cheapest place for parts will be a Navistar Truck part place not Ford. Advance and the like, I don’t really trust their parts on these engines. For the labor involved, I’d rather have genuine Navistar parts.


Yes, I did remove the battery cables before checking for voltage. Wasn’t sure if they were connected, so I figured, better safe, than sorry.

Thank you for all the helpful advice.

Have since taken both batteries to a parts shop, and had them charged, and checked out. Also replaced the column ignition switch.
Parts shop said both batteries were good after charging. Replaced batteries in Ex, and it started fine.
And continued to do so for about two weeks, then a couple of days ago, it went back to it’s old tricks; turn the key, and nothing…
I can jump the fenderwall solenoid to start it, but that’s the only way, so far…