Hey guys. I got everything hooked up (new in-tank pump and sending unit). The fuel filter canister leaks a bit cause the gasket broke when I took it out to look at the orientation of things in the canister. It is still hard to start, but I believe I set the initial timing wrong as I still am unclear as to how to drop the distributor in correctly. Anyway, my question for this problem is what would cause a brand new sending unit not to work??? Any ideas???

 

When you put the new assembly in did you take care to make sure that the float didn't hang up when it was put in the tank? Other than that it could be a wiring issue,the selector switch or gauge.
Also here is a video showing how to drop in a distributor

http://www.youtube.com/user/MSDvideosdotcom

 

I am pretty certain it wasn't going to hangup somewhere. So it could be the gauge huh? Do you recommending me take the dash apart and get a looksee to see if something not right? Isn't there a way to test the gauge by grounding one of the wires? Forgive me but the Haynes manual is becoming a piece of **** overall, but especially in this area. No mention of any of this.

 

On the older models you could short the lead to the sender at the tank to ground and the gauge would max out. I'm guessing that you could do this with this one too,also check the ground going to the sender. Was the gauge working before the swap?

 

No gauge was pegged to 0 as well, but you lost me nitehawk. Sorry. As far as grounding anything I do not know what any of the pins are (power ground, ect). There are 4 pins on the connector. Not sure which is ground or what the lead is. Any help there? Thanks.

 

On the plug at the pump If there are 4 wires there should be 2 large wire that goes to the pump and 2 smaller that goes to the sending unit.But since it wasn't working before you need to check the ground to the plug then the wires from the tank to the tank selector switch for a break or the sending wire back to the switch for grounded condition. Then from the switch to the gauge itself .

 

Here are a couple of diagrams. The first one is easier to follow but the sender/pump grounds are not shown correctly.
The diagrams show the wire colors so you can know what is what for testing.

http://i608.photobucket.com/albums/t...FIfuel-sel.gif

Ford shop manual diagram:
http://i608.photobucket.com/albums/t...0/duelfuel.jpg

 

This is for the dual tank system with fuel pressure activated tank switching valve. (NON electric).
Valve looks like this:
http://i608.photobucket.com/albums/t...ordfuelres.jpg
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Here is more info about how to test that I pulled from a past thread.

You will need a multimeter.

Sender test:
The best place to test is at the dash tank switch connector with the connector removed from the switch.

Set your meter to measure Ohms. (Probably the lowest scale)

Front tank: Put red test lead on the DB/Y wire. (Dark Blue / yellow)
Rear tank: Put the red lead on the Y/LB wire (Yellow with Light Blue stripe)
Put the black lead on a good metal chassis ground.

You should measure ~10 Ohms full tank and ~73 Ohms empty tank or somewhere between depending on the fuel level.

Gauge test:
Turn your ignition switch to on.
Set meter to read DC volts.
First measure at the tank connector. (Make sure the corresponding tank is selected on the dash switch).

Front tank: Red lead on the DB/Y wire.
or
Rear tank: Red lead on the Y/LB wire.

Black lead on Ground.
The gauge wire should pulse ~5 volts every few seconds.

These can also be measured at the tank select switch if needed.

OR

Alternate gauge test:
Momentarily ground the DB/Y (front) or Y/LB (rear) wire and the gauge should peg full. Be careful not to ground the wrong (Pump) wire or you could blow a fuse.

 

Thanks guys. Klricks you are like a wizard dude. I will give it all a try and report back. By the way, the selector valve was removed by the previous owner, but I have it as he left it in the truck. Can this also be a cause?

 

One thing I just don't get.....The selector valve on the diagram has 2 wires on one side and 4 coming in another. Now the selector valve has a 5 pin connector. Thats 5 pins going one way. How in the hell does it have 2 going one way and 4 in another???? Is that just me not reading this correctly. I have been studying these all day and at the end of the day it makes no sense to me. I've got a 5 pin selector valve and 2 4 pin tank connectors. I see on the diagram 1, 2, 3, 4, 5, 6. I count on selector 5 pins. Any help?