Switching tanks

kbenz

Full Access Member
Joined
Jul 22, 2020
Posts
161
Reaction score
60
Location
kannapolis, NC
About how long does it take after switching tanks to get new fuel through the system? 7.3 non turbo
 

Kizer

Supporting Member
Supporting Member
Joined
Mar 22, 2007
Posts
673
Reaction score
201
Location
Denton, Texas
Not long, if you’re running down the road, and you accidentally drain a tank, you have time to switch tanks before you stall the truck.
 

Cubey

Full timer RVer
Joined
Oct 18, 2017
Posts
3,604
Reaction score
1,310
Location
USA
I switch tanks when driving and the engine doesn't notice. The injection pump has some suction of it's own, so it can borrow from the fuel filter if it needs to while the tanks switch in the second or so it takes.
 

Nero

Full Access Member
Joined
Jan 3, 2022
Posts
453
Reaction score
348
Location
OR
The few times I've accidentally ran a tank dry enough to stall, I usually dow shift one gear and press the accelerator to max, usually the engine restarts itself. Also, not a good thing to do, to run it dry, it's bad for the pump.
 

Kizer

Supporting Member
Supporting Member
Joined
Mar 22, 2007
Posts
673
Reaction score
201
Location
Denton, Texas
The few times I've accidentally ran a tank dry enough to stall, I usually dow shift one gear and press the accelerator to max, usually the engine restarts itself. Also, not a good thing to do, to run it dry, it's bad for the pump.
Yep, that will sure “do the trick”.

I guess that I’ve learned: If I “suddenly” experience air intrusion symptoms, flip the switch!
 

Clb

Another old truck
Supporting Member
Joined
Mar 1, 2013
Posts
4,988
Reaction score
1,439
Location
nannyfornia
I'm always headed uphill pulling the dang 5er in the 93 now empty and flat it will just catch about the time panic sets in using Nero's method.
Op it's a crapshoot.
Even with the Holley red I aint warm and fuzzy when this happens.
My 88 would switch on the fly easily, but drain it, not so well.
 

Jesus Freak

Registered User
Joined
Apr 3, 2022
Posts
678
Reaction score
471
Location
Crestview, FL
When I'm cruzing along and I detect WMO problems (fuel filter clogging) I switch to my diesel tank and within a mile, like before half a mile, I'll start gaining momentum again. So, baced on that, if you figure it takes a moment for the diesel to kinda "scrub my filter", to switch must be pretty quick. Maybe look at the GPH rate and guesstimate.
 

Clb

Another old truck
Supporting Member
Joined
Mar 1, 2013
Posts
4,988
Reaction score
1,439
Location
nannyfornia
fwiw
crawl under the fsv have someone hit the dash switch with power ON and listen to how fast the solenoid moves the valve....
It should ppopp like half a second or less.
if it lags and or does not make a noise it may be stuck {lookup old bulls fsv 101 in tech} showerheads are notorious for this
 

IDIBRONCO

IDIBRONCO
Joined
Feb 5, 2010
Posts
9,815
Reaction score
7,944
Location
edmond, ks
The few times I've accidentally ran a tank dry enough to stall, I usually dow shift one gear and press the accelerator to max, usually the engine restarts itself
I've seen it work and I've seen it not work. There's a lot of different factors that determine whether or not it works.
 

Nero

Full Access Member
Joined
Jan 3, 2022
Posts
453
Reaction score
348
Location
OR
In my case I was on the freeway doing 60, by the time it restarted I was down to about 45ish. Only ever done it twice. I try not to do it.
 

12pilgrim

Registered User
Joined
Jan 12, 2021
Posts
31
Reaction score
29
Location
Nashville
'86 6.9. I replaced both sending units and the fuel tank selector valve and it switches beautifully, no issues so far at all. I can look up the part numbers that I used if you're thinking of replacing anything
 

kbenz

Full Access Member
Joined
Jul 22, 2020
Posts
161
Reaction score
60
Location
kannapolis, NC
'86 6.9. I replaced both sending units and the fuel tank selector valve and it switches beautifully, no issues so far at all. I can look up the part numbers that I used if you're thinking of replacing anything
I have an almost new oem one on the shelf I took off when I put the wheel lift under it.
I’m running wmo. I was just wondering if I forgot to switch tanks how long would it take to clear the oil at an idle
 
Top