THIS is getting old!

[mexicanjoe]

Ok here's the skinny on Ol' LuLuBelle when I changed out her fuel selector valve.
When pulling out of the rear tank: NO PROBLEM! When pulling out of the front tank it surges like its starved for fuel!!I filled up both tanks. I
tried to run the truck on the front tank: No dice!
I think I may have an obstruction in the line or the pick up tube has fallen off in the tank. However: if left idling the engine runs fine, its when I need the added fuel for acceleration that this problem pops up. Your thoughts on this problem , brethren. I await your answered with anticipation.

 

[ihc1470]

Drop the tank and discover your answer.

 

[Clb]

Back blow the lines, ( start at sub 20 psi)remove the fuel caps FIRST, not real easy to obstruct the flow doing that ( but Murphy) so look for kinks in them dumb plastic lines.
Any chance of it being coincidence?
Check fuel delivery pressure at 2000 + rpm and then Momentarily floor it and observe the pressure.
Good luck

 

[MadMac]

I think I may have an obstruction in the line or the pick up tube has fallen off in the tank. However: if left idling the engine runs fine, its when I need the added fuel for acceleration that this problem pops up.

In short - @ihc1470 - is likely right. B/C things run fine on the rear tank, the only things which could be wrong are between the tanks switch valve and the tank, inclusive. The valve - highly unlikely - I'd guess you would see other problems with the rear tank... Highly unlikely, but possible, there is a clog in the line to the valve. More likely - the pickup is bad. Most likely - the filter screen on the pickup is clogged - particularly if you live in a place with inclement weather and/or it has been outside most winters (condensation and resuting rust in the tanks). Since all three really require dropping the tank...

On my '85 I've replaced both front and rear tanks. The rear tank - which was an absolute PITA to mount - still has problems with drawing fuel below about 1/3rd. Both have venting problems when fueling up - despite replacing the vent tubes and rollover valves. Both despite valliant efforts for both not to occur. The fuel system is... picky.

 

[asmith]

mine had this problem on the back tank for awhile then it started happening on the front tank. it would idle fine, but anything above 1800rpms it would fall on its face and starve for fuel. Dropped both tanks and both showerheads were gone and the pickups were completely obstructed with the pieces. I am not sure how any fuel got through. Went to a big single rear tank after that. Works great.

 

[Jesus Freak]

I tell ya, if you can ever get fuel to these engines they'll just run and run......the trick is consistently getting fuel to them....

 

[Clb]

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[Clb]

 

[KansasIDI]

Ahem… (cough cough)

https://www.zoro.com/groco-6-port-fuel-valve-12-in-supply-fv-65038/i/G505728413/

(A) Problem solved!

But yeah, definitely check out what’s going on inside your tanks.

 

[mexicanjoe]

CIB I took your advice!! IT WORKED!!! I'm repairing/replacing things on LuLuBelle one paycheck at a time, the showerheads are getting replaced. Since we are in the middle of the oilfields- hot vatting the tanks is no big problem. Eventually, Ill have new glow plugs, a new rear window etc. etc. While I could care less about the appearance of my pick up, I want it reliable. I live 2 miles from town, but the ranch is 36 miles away and I don't want to be stuck on a lonely road at night.


Guys , I cant thank you enough. I promise I will either dance at your next wedding or play my accordion there. ( I'm currently taking lessons from a homeless man that lives out in the desert- resembles Yoda he does!)

 

[Jesus Freak]

CIB I took your advice!! IT WORKED!!! I'm repairing/replacing things on LuLuBelle one paycheck at a time, the showerheads are getting replaced. Since we are in the middle of the oilfields- hot vatting the tanks is no big problem. Eventually, Ill have new glow plugs, a new rear window etc. etc. While I could care less about the appearance of my pick up, I want it reliable. I live 2 miles from town, but the ranch is 36 miles away and I don't want to be stuck on a lonely road at night.


Guys , I cant thank you enough. I promise I will either dance at your next wedding or play my accordion there. ( I'm currently taking lessons from a homeless man that lives out in the desert- resembles Yoda he does!)

Good job, id prefer you just turn the new stereo in your truck up....

 

[IDIBRONCO]

I live 2 miles from town, but the ranch is 36 miles away

Sounds like a great place to live and work!