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New project 94 C3500 350

The brand new tester did leak fuel but I think I got enough of it blocked off to be kinda accurate.

I also checked voltage at the pump and got 2 grounds, one at 13.5v, and one at 6v. This sound right?
 
You have 3 wires, 1 is a tank ground, 1 is pump power, and other is sender for the gauge. A tbi needs at leadt 8 to even run decent, but 11-12 is better. I'm surprised the injectors even pop at that pressure.
 
Like I said the gauge leaked pretty bad but I got it to a slow drip. With the gauge hooked up it ran like it does on cold mornings, unhooked it and it was back to its recently normal condition.

I have 4 wires at the tank head. They are badly faded and have at least 3 ft of splices 3" from the tank plug. One was greenish, one yelowish, one black, one black with white stripe.
 
Where do you find new tanks? I didn't see the 31 gallon tank on rock auto

Also, I'd like to fix all the splices in my wiring. Do they sell that harness?
 
From what I could find of pics on rockauto, you should have a 3 wire plug and a seperate ground with a ring terminal. 2 should be direct grounds, the one in the center of the 3 wire plug should be sending unit, and pump power. The 2 grounds I would think should be solid grounds. If you're not getting a good ground, then that could easily be your problem. Remember, grounds, grounds, and grounds.
 
As to tanks, does it have a single or dual tanks? Single tank is 34 gallons in front of axle, dual tanks is 25 in front and 31 in back. Rockauto had all 3 listed when I just looked.
 
13.5v power and 6v gauge sender wire sounds logical though wouldn't you think? I was below 1/4 tank, and by below 1/4 I mean the gauge read 3/4 lol
 
The rear tank is only meant to be a transfer tank if it works like the diesels. They only came with a really low pressure pump in them iirc. The front tank was the one that had the pump to run the engine. The rear pump should be a 6-8 psi pump while the front tank was a 13 psi pump. The sender wire should have arou,d 6 volts on it backprobing with less than a 1/4 a tank in it.
 
So someone removed the main fuel tank from this truck? And perhaps are attempting to run it on a transfer pump rather than the normal engine fuel pump?
 
Just thinking out loud here.

If Someone replaced the fuel pump with a standard pump instead of the cab and chassis pump would that cause me to feel like I've got a smaller tank?

Basically, is the standard 25/36 gallon tank shallower than the 31 gallon tank?
 
They all 3 use different assemblies. The behind the axle setup is quite a bit different than the in front of the axle setups.
 
So not possible to put the wrong pump assembly in? Sounds like the pump assembly has an issue of some sort but not sure what direction to go on this.
 
Do they sell the pump, pickup attachment, and a new wiring harness as a kit?

Just used my duramax to rid the world of a deer, looks like it's in for a new hood, bumper, passenger fender, and both passenger doors... the 94 will be promoted to Daily driver and needs heat and fuel issue fixed.
 
Rock auto doesn't have an AC Delco in sending unit/pump assemblies, what is preferred between Bosch and Delphi?

Any tips on temp and blend doors that have had their cables chewed off by mice? Do I have to pull the dash to run the cables?
 
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