• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

METRUM ROD FSU Accuracy ?

WarWagon

WarWagon

Well it hits on 7 of 8...
Messages
10,694
Reaction score
8,475
Location
AZ
I have a 34 gal tank on the 1993 that appears to only have a working capacity of 24 gal. It never reads over the full mark and in fact sometimes never reaches the full mark by 1 notch. I have filled the tank till I see fuel in the fill neck. I am sure the float can't go all the way to the top due to the vent tube interference.

I have an aftermarket replacement tank and pickup assembly.

Is the MSU leaving 10 gal in the bottom of the tank while reading empty? Is it supposed to read below the empty line? Is the aftermarket vent tube extension on the tank too far down? IE calibrated length of vent tube for 24 gal instead of 34?

My memory is faded but I recall being near empty and taking a couple 5 gal water jugs of bad fuel out of the tank before dropping it with the MSU in place couple years ago or so.

Is this the amount of fuel that needs to be left in the tank to prevent stalling?
 
If the vent tube wont let float all the way up it will only read as full as it can, until it hits the vent tube.

I have also been sending new units out uncut, so the user can meassure exactly what length they'll need.
It amazes me how much difference there is from tank to tank. Originally I thought I would only have to make 3 MRFSUs
24,34,43 gal tanks but the depth of tank, baffles....ect seem to be different on every tank. Why I send them uncut now.
 
So I have a early production unit then.
I also have an aftermarket replacement tank that also makes a difference.
 
I know on mine I made it about 3/8" to short for my 42 gallon tank. I still have about 5-6 gallons left on E, but it sits on full for almost 125 miles now and if I had made it any longer it would have stayed on F even longer. I did have to cut about 3/4" out of the vent tube to get it to let the float go all the way up. My only real complaint is that from 1/8 to almost 1/2 it drops pretty quickly and bounces a lot. Above or below that area it works great.
 
You must log in or register to reply here.
Back
Top