Stranded

Went to town on sunday.

On the way home, I ran out of gas.

Or did I? Yes, I did. Or did I? Yes, I did. Or did I? Yes I did......

I hope you get the picture. I "ran out of gas", (and yes, I know it's diesel, and I had better NOT have gas in there. Bite me. ) 6 times. Fiddled with the fuel selector valve 5 times, and got it to start up and drive again for any where from a 1/4 mile to 4 or 6 miles, then 'ran out of gas' again, and went through it all over again. Final time it simply would not start again, no matter how much fiddling I did with the switch. Neither tank works.

Here's the strange stuff first. (As if it wasn't strange to 'run out of gas', and then start up again, and drive awhile then run out again, the start agai..... yeah.)

*I am pretty sure the rear tank ran completely out of fuel and that is what started this whole debacle. Howsomever, when a friend picked me up, we got some diesel, and I tried pouring it into the rear tank, it was as if the rear tank was already over full. It took about a half gallon, then overflowed. I tried again after letting it settle down. A few times, it "burperd" then took a bit more. But never took more than a quart at a time. And finally, the fuel was sitting right up at the top of the filler neck, about to spill out, and would NOT go down any further. No amount of shaking would do it. Put a stick down in there, no change in the level. Etc. So... Like the tank was over full. (But checking it again this morning, that fuel is no longer sitting up at the neck of the filler. So, go figger.)

As I said, I swear that rear tank should have been completely empty.

*When fiddling with the switch... I never could get it to start again, on the front tank. But the front tank should have been half full. Every time that it started again, it started on the rear tank. But that tank should have been empty. Yadda yadda You see where this is going.

*I am positive that the amount of fuel that could have possibly been in BOTH tanks, would not have come close to filling up one tank. So it couldn't have been that it pulled from one tank and returned to another. Etc.


I ended up having to get a tow. The tow guy wrote down the mileage on his records.... 131666. We both got a laugh out of that! (And yes, you can probably add at least 400k to that.)


Life intervened.

Today I am getting to the job of testing and seeing if I can get this thing started and working again.

Yes, I know. Bleeding and all that. I don't need the simple advice. Just kind of recording this, as a way to keep my thoughts straight, and maybe bounce things off you guys as I go along. Hear what you have to say. Etc...

Since I have had time to think about this, I have decided to start with the switch on the dash. I had the dash apart, not that long ago. It's a long shot, but it's possible I didn't get the connector back onto the switch, well enough. Either way, I will test the switch, and the connector. Then will probably jumper the connector, just to take the switch completely out of the equation.

If that doesn't get some fuel coming up to the filter, (Yeah, no fuel up at the filter right now. It's not just not at the injectors. It's not making it to the filter head.), then I'll have to crawl under and check out the selector valve.

Wish me luck.

I forgot the other 'strange thing'....

Put the switch on the rear tank, the gauge reads empty. But the gauge wasn't working on the rear tank, anyway. That's why I ran it out.

Gauge stays on empty when switched to the rear.

Put the switch on the front tank. Still empty. Unless you turn the ignition switch to the on position, and let it sit. Then it very slowly comes up to about a half a tank. Which is what the front tank should actually HAVE in it.

But if you turn the ignition switch to the start position, the gauge immediately jumps back to totally empty. Then slowly climbs again, once you let it off of start. (Note: It has never done this before. It has always been that the gauge reads what the level is, with no change with any change of the key position. Or, if you flip the switch it would quickly make its way to the correct level of the newly selected tank. Otherwise, always rock steady.)


Given all the info from both of these posts, so far, maybe you can see why I am starting at the switch, instead of elsewhere... And working to eliminate it from the loop, just to be certain of every step from that point on.

Well actually, I am going to start by replacing every blasted fuse in the fuse block. Tired of guessing about those all the time. I'm just going to put all new ones in. BTW It's not the fuse. Already checked that.

Do this...

1. pull fuel line to pump and put air in tank(even if you have to blow in the tank), no fuel go to 2
2. pull output from from tank selector valve and repeat with air in tank, no fuel go to 3
3. pull input from given tank to selector valve and repeat with air in tank, fuel go to 4 and no fuel 8
4. switch inputs on the selector valve and repeat with air in tank, fuel go to 5 and no fuel 6
5. this could be the selector valve not switching or bad wiring.
6. bad selector valve and try a bypass and recheck at the pump to confirm
8. keep working back to tank and are you sure you are putting enought ait in tank.

Thank you. Crawling under the truck and taking a mud and diesel bath is the last thing on my list of to-dos for this diagnosis.

I'd already planned, (when I reach the right point.), to actually jumper the switch connector at the dash, to more or less 'hard wire' the selector valve on the frame, to the front tank. Then blow backward, (Gently.), from the engine bay, to see if the selector valve is stuck or blocked.

Mine behaved similar when my FSV died. I don't know what actually happened, (I'm assuming it sucked up a piece of the old strainer) but it had blown the fuse and melted the switching motor.

Just FYI in case you don't already know (but I think you do?) The gauge switching is physically done inside the FSV.

You flip the switch on the dash and the guts slide over and stop, contacting the other sender wire. When you flip the switch back it reverses polarity to the motor (if I remember correctly) and then its goes the other way, contacting the other sender wire.

I know you've messed with the fuel system a few times so I'm thinking you know that, but just in case you didn't I figured it might be helpful.

Yes, I do know that. But it's good to kind of do a review. Thank you.

I am leaving crawling under, for last. Not relishing the diesel bath that I WILL take, once I lay hands on that valve...

Got all the fuses changed. Tested the old ones. All good. But at least now I am not guessing.

Checked your water filter? I had the same issues and my filter was full of water.

Never-Have-I-Ether

If you don’t have an electric lift pump, it might be worth picking up one of those cheap generic ones just for diagnostic purposes. You can know whether system is delivering fuel without having to crank the engine. You can also use it as a transfer pump to move some diesel from your overflowing rear tank to the front.

I have a feeling that the selector valve itself is the problem. Maybe some sort of obstruction in the valve mechanism. Good luck and keep us updated.

I think the FSV did it! But I know how these @Selahdoor(Columbo) mystery novels go, so I don't want to jump to conclusions. Selahdoor, I just want you to know, I really appreciate and enjoy your threads, man. (This seems facetious, but I'm really serious)

You know that long shot?.........

Yeah. Connector on the back of the dash switch was completely off.

Puzzler... If it was completely off, HOW in the actual EFF did switching that disconnected switch have any effect whatsoever on the gauge, let alone which tank was being used?

As I said... Flipping the switch made a difference in the fuel gauge reading. Flipping the switch also made a difference, in whether the truck would actually start again, or not.

Or, maybe I am full of it, and it was doing nothing at all.

I'm not stupid. And I'm not blind. I saw a difference being made in the gauge. One way it said half a tank, the other way it was empty.

Only thing I can think of is that the connector was slowly making it's way off the back of the switch, over time. That caused all the problems. And it made it's way the rest of the way off, the last time it died. Or while being towed home.

I am not going to know anything until the batteries charge up a bit. I had run them down most of the way, trying to get it to start. And just sitting there a couple of days, it seems to have run the rest of the way down. Won't turn over now. So I'll leave the charger on it for an hour, and see what happens.


If I go back over this logically, I can kind of make most of the data fit logically with one thing. I never actually reconnected the switch in the first place.

But that REALLY makes for some strange data in a couple of ways.


The ways that it does make sense...

I completely filled both tanks, after having taken the dash apart, and never reconnected the dash switch.

I THOUGHT the switch was working, so when I saw that the front tank was half full, I flipped the switch to the rear tank.

Gauge doesn't work. That's strange. It just stays at half a tank. Ok. I had fiddled with some wires in the back, so maybe I had jostled the wires for the gauge. I'll check that some day. Meanwhile, I am running the back tank. (I THOUGHT.) I'll wait until that reaches about 1/4 tank or so, then switch back to the front, and the next time I go past the station, I'll fill up.

This is my usual routine. Never let either one go below 1/4. Use one until it is half, then I can use the other with impunity, knowing I'll have enough left in the first tank, to get to town or wherever, once the second tank hits 1/4. I do this because occasionally I can't just stop at 1/4 and will run out or get close to it. And I need to know there is at least 1/3 to 1/2 a tank in reserve to get me back to town.

So.... here I am tooling along, mistakenly thinking that I am running on the back tank now, but the gauge isn't working. So I just let it run out. (since I installed the electric auxilliary pump, I can always get it started fairly quickly if it runs completely out.)

It ran out.

Flipped it to the front. (The gauge DID CHANGE. And started that dipping thing, every time I turned the key.)

Wouldn't start. Flipped it back to the rear. It started and ran.

Died. Flipped it to the rear, it started, but didn't run much.

Flipped it to the rear, it started, flipped it to the front while running, kept running a while. Then died. Did exactly the same thing, several times.

The final time that it died, it didn't matter what I did with the switch. It wouldn't start any more.


I can't be sure of anything at all until the batteries charge up and I get it started again. But, given what I know at this point... My conclusion: It LOOKS like the connector either was never on the switch, or it worked it's way off. I think it was never on. And all that flipping of the switch did absolutely nothing. Seeing the gauge move, was just a strange anomaly.

I think I was running on the front tank all along.

With the switch connector on tightly right now, I do know this. With it flipped to the front, the gauge shows empty. With it flipped to the back, it shows full. I am tending to agree with this, given the way the rear tank acted like it was full, when I tried to add fuel.

I'll come back and conclude this thread if I get it started and find that the problem is fixed. Otherwise I'll continue and I'll report whatever else I have to do.

Okay, this isn't a mystery novel, it's not even an episode of Colombo! So what is it?....... we've found ourselves drawn into........
THE TWILIGHT ZONE!!!

Ok, I got it started. I'll let it run about 20 minutes to charge the batteries up.

I knew I was making progress when, with it switched to the rear tank, I started seeing air and fuel at the clear line in front of the fuel filter.

Then I let the electric pump run for a while, while I held in the schraeder valve. When I got a steady stream out of the valve, I checked to make sure the valve on the top of the IP worked, then opened all the injector lines and turned it over until I saw a bit of fuel at each of them.

Tightened. Then still had to let the batteries charge, then turn it over and over and over.... 3 times had to let the batteries charge up again. Before it finally bled enough to start!

It died pretty quickly, but I wasn't giving up on it then! It did start up right away again, and ran very rough while the injectors all finally filled up.

Now it is just sitting there running, because I think charging the batteries that way is better than with the charger.

I don't think I am going to bruise my brain, trying to figure out how a totally disconnected dash switch could possibly have affected the gauge. We will just leave that one in the zone...

I do know I am glad that I got to do all that bleeder work in my driveway, and not out on the side of the highway!

Selahdoor said:

Now it is just sitting there running, because I think charging the batteries that way is better than with the charger.

Click to expand...

This is a theory of mine too. It really does "feel" like the batteries perform better being charged by the alternator.

My guess is that the connector on the back of the switch was barely hanging on enough to sort of work. It switched the gauges, but maybe not the tank. Another clue ,to me, is the odd way that your fuel gauge was working with the key in different positions. I think that It finally fell completely off when you were moving the dash parts around.

is this whole forum having fuel gremlins or what?

glad you got it going