Fuel tanks & stalling

[ghunt]

In light of my recent posts about diesel prices jumping, I went ahead and filled both tanks last night. Now, this is the first time I've used the rear tank since I put it back into the truck.

After filling up I went down the road, and I was afraid it would probably stall when I switched to the rear tank so I tried to do it while I had some momentum. However, the actual changeover took longer than I expected and the truck stalled out once it finally did because I was coming up to a light. Also the fuel filter light came on as soon as I switched to the rear tank.

Anyway, I had to pull it off the side of the road and bleed the air out of the system. I got it started again, still on the rear tank, and it ran for a minute or two and died again. I switched it back to the front tank, again bled the air out, and finally got it restarted again, and also noticed the fuel filter light was now off.

So what's that all about...I recently replaced all the hardlines to the rear tank with rubber hose because the hardlines were rusted through. Could it be sucking those lines shut?

 

[icanfixall]

That depends on what fuel lines you installed. Check the line again and look for a pinched ot bent area.

 

[HankHill]

I saw at the auto part store, its that rubber fuel line but it has like nylon threading inbetween the sidewalls of the rubber so its more strong, did you use that type? I was going to use it for my rear tank because my hardlines rusted holes also

 

[ghunt]

I used plain old rubber fuel hose...I was told it would be fine. I hope it's not sucking the hoses shut.

 

[Tarantula]

Fuel hose

I used plain old sae30R7 fuel hose because my fuel lines were rusted out and I have had no problems at all. I am using the standard mechanical fuel pump. I did away with the electronic fuel switching and went with manually operated fuel valves.

Can you siphon fuel out from under the truck using the fuel line to the rear tank? Mine will draw fuel out easily just by unhooking the fuel line at my fuel valve.

 

[ghunt]

Well I think then that the truck may just need to be run. I had the rear tank out of the truck for awhile (had it boiled out) and so those lines have been dry since they were reinstalled. I know it's getting some air in the system there, I may have to get on the highway and switch to the rear tank while I'm going down a long hill and get the air out of the system completely or something.

 

[ghunt]

Alright, I messed with this again tonight...wanted to see what it would actually do. I got on the highway, onto a long downhill section, and switched to the rear tank. Once again the fuel filter light came on just a few seconds after I switched it, then the truck stalled (still moving). I kept it in fifth gear until I slowed clear down to 45 mph, but it still hadn't gotten fuel. I switched it back to the front tank and literally in seconds it fired back up and ran fine.

So basically...it seems that I'm not getting fuel from the rear tank, at all. Now I'm just wondering exactly WHAT the problem is...line getting sucked shut? Tank switch valve bad?

 

[dakotajeep]

I also had regular old fuel hose on mine without any issues. Is there a possibility that something got into the fuel lines that could be causing issues with the FTSV? That was what caused my fantom fuel starvation issue...might not be your problem though. Just trying to help.

The only way to know for certain would be to bypass the FTSV all together.

Good Luck,
Thad

 

[DeepRoots]

Here is what I would do:

1. Set switch to rear tank. pull loose the line from the rear tank to the FSV. Apply vacuum and see if ya get fuel. If yes, try doing it ahead of the FSV, if not, you mixed the return line and the supply line (don't feel bad, I done it before too).
2. If you do indeed get fuel through the fsv try blowing through the return line (clogged return will kill an engine instantly).
3. If things still aren't working for ya, swap the suction for the front/back tank at the fsv and see what happens.


Drew

 

[DeepRoots]

on another note....
There have been a few of these 'fuel supply' posts recently.
Everyone on this site that works on trucks with a mechanical lift pump needs one of these:
http://www.autozone.com/autozone/ca...&parentId=00-10&itemId=478-10&productId=70116

and a pair of vice grips. clamp the fuel line with vice grips and apply 22inches of vacuum. If it holds for lets say ten minutes, your wonderful. If you need to constantly pump up the vacuum or you get air bubbles, you obviously have a problem.

Drew

 

[ghunt]

I have an electric pump...sitting in the garage.

Wanting to make that a project sometime soon hopefully...

Well, I am wondering if maybe I got the line connections switched around when I hooked them back up to the selector valve...but I don't think I did, as one is bigger than the other where they connect, I thought they could only go on one way?

 

[DeepRoots]

I recently replaced all the hardlines to the rear tank with rubber hose because the hardlines were rusted through.

I assumed you used the same rubber hose for both. If so, it's easy to do.
Drew

 

[icanfixall]

I would remove the hose from the tank supply to the selecter valve. See if fuel flows out of it. It not apply some low pressure air to it. You will hear it bubbleing in the rear tank. Then remove the line off the selecter valve to the lift pump. Apply some air pressure to that line... I know that line works but just prove it works. Your issues are in the selecter valve or the line from the tank to the selecter valve.... This proves out because you can pull from the front tank just fine... Maybe you kinked the hose or pinched it somewhere. I did that once on my ski boat. I removed the seat and when I put it back I got the fuel line hose pinched between it and the seat frame... Whole lot of no go anywhere... Just returned to the seen of the crime and found my mistake.....

 

[ghunt]

I assumed you used the same rubber hose for both. If so, it's easy to do.
Drew

I kept the clip ends from the factory line though...but now I wonder if I got THEM switched around on the wrong hoses so it's hooked up wrong even though it looks right. Hmmm...

Also what's a good low pressure air source? I don't have a compressor myself. I will have to look for pinched lines somewhere.

 

[icanfixall]

Well... Without a compressor maybe if the fuel isn't flowing out the open hose you could wrap your lips around it and blow... I'm not being funny here either. You may just be able to blow back into the tank and hear the bubbleing. If you have an electric fuel pump you could reverse that and pump out of a container some fuel back into the tank to prove the line is clear... Any cheap electric pump will do fine....