Big Blue's Transformation

[ArdWrknTrk]

Oh, on a positive note the battery seems to be coming up nicely. It is at about 12.7 volts on the 10 amp setting so is nearing full charge.

And, there was an interesting result when I filled the charger's switch to the 50 amp mode - voltage climbed quickly to 14.5 volts. However previously when I did that the voltage only went up a few tenths of a volt. That seems to say to me that previously the battery was converting the current to stored potential via the chemical process, where now it isn't able to do that and the voltage climbs.

Does that make sense?

Yes it makes sense.

It could also mean that sulphate had bridged anode to cathode and you were charging into a dead short, but I don't have a lot of experience with these batteries.

Have you considered that you got a duff fuel regulator?

QC has been sadly lacking with Holley of late (new conglomerate structure)

[Gary Lewis]

Yes it makes sense.

It could also mean that sulphate had bridged anode to cathode and you were charging into a dead short, but I don't have a lot of experience with these batteries.

Have you considered that you got a duff fuel regulator?

QC has been sadly lacking with Holley of late (new conglomerate structure)

Yes, I’m wondering about the regulator. I have one of their lesser model return style that I might try if I find that the flow is in the right direction. If it works then that one is bad.

[Gary Lewis]

Yes, I’m wondering about the regulator. I have one of their lesser model return style that I might try if I find that the flow is in the right direction. If it works then that one is bad.

Looks like I have a duff regulator, although I do want to do some more thinking and testing before I take it out. And, I'd like your thoughts.

 

Here's the proof. I put a push button switch on a pair of alligator clips with 6' of wire. Then I put the clips across the oil pressure switch, fed it down under the truck, pulled the outlet hose on the fuel pump, and pushed the button. Looks pretty conclusive to me, but what about you'uns?

 

[Gary Lewis]

Looks like I have a duff regulator, although I do want to do some more thinking and testing before I take it out. And, I'd like your thoughts.

 

Here's the proof. I put a push button switch on a pair of alligator clips with 6' of wire. Then I put the clips across the oil pressure switch, fed it down under the truck, pulled the outlet hose on the fuel pump, and pushed the button. Looks pretty conclusive to me, but what about you'uns?

 

Ok, now I need to think through what the next steps are. And it seems to me that now that I know the fuel is being supplied through the filter that there are only three possible causes of the problem I'm seeing of high pressure to the carb:

 

1. Swapped Lines: Perhaps somehow, in spite of the visual inspection I've done, the supply and return lines got swapped between the filter and the regulator. So to prove that I guess I should pull what I think is the supply line from the regulator and turn the pump on, briefly.
2. Return Plugged: If the return is plugged then I guess the regulator can't work, so to prove it is open I need to pull that hose off the regulator and blow compressed air through it. But, does the pump have to be on to open the port to allow fuel to return? Surely it does or with the returns wyed the fuel could go into the wrong tank. Right? Maybe I should do as Bill suggesting and run the return into the neck of the tank to ensure it isn't a valve in the fuel delivery module blocking the return?
3. Bad Regulator: If #'s 1 & 2 check out ok then the regulator is probably bad. With the supply and return lines off the regulator I can remove it for testing. I was thinking of using air, and since this is a return style regulator I'll just vent the "return" and put a gauge on the outlet. Will that work? Venting the "return" is making me question this approach.

 

Help me think through this, please!

[85lebaront2]

Ok, now I need to think through what the next steps are. And it seems to me that now that I know the fuel is being supplied through the filter that there are only three possible causes of the problem I'm seeing of high pressure to the carb:

 

1. Swapped Lines: Perhaps somehow, in spite of the visual inspection I've done, the supply and return lines got swapped between the filter and the regulator. So to prove that I guess I should pull what I think is the supply line from the regulator and turn the pump on, briefly.
2. Return Plugged: If the return is plugged then I guess the regulator can't work, so to prove it is open I need to pull that hose off the regulator and blow compressed air through it. But, does the pump have to be on to open the port to allow fuel to return? Surely it does or with the returns wyed the fuel could go into the wrong tank. Right? Maybe I should do as Bill suggesting and run the return into the neck of the tank to ensure it isn't a valve in the fuel delivery module blocking the return?
3. Bad Regulator: If #'s 1 & 2 check out ok then the regulator is probably bad. With the supply and return lines off the regulator I can remove it for testing. I was thinking of using air, and since this is a return style regulator I'll just vent the "return" and put a gauge on the outlet. Will that work? Venting the "return" is making me question this approach.

 

Help me think through this, please!

Gary, I have faith you will overthink it. You should be able to test the regulator with air, mount a gauge to one port air in the other, center open and bring the pressure up until it opens the center. If it does then set it where it needs to be and put it back on. Run the hose like I suggested to validate the setting. Also try pressurizing the return line and see if (a) you can get air through it and (b) what kind of pressure it takes.This is the FDM that was in the tank when you bought BB isn't it? Could be the valve is stuck and just needs a good shot of pressure to pop it loose.

[ArdWrknTrk]

Gary, I have faith you will overthink it. You should be able to test the regulator with air, mount a gauge to one port air in the other, center open and bring the pressure up until it opens the center. If it does then set it where it needs to be and put it back on. Run the hose like I suggested to validate the setting. Also try pressurizing the return line and see if (a) you can get air through it and (b) what kind of pressure it takes.

This is the FDM that was in the tank when you bought BB isn't it? Could be the valve is stuck and just needs a good shot of pressure to pop it loose.

This is what I told him the other day, Bill

[Gary Lewis]

Gary, I have faith you will overthink it. You should be able to test the regulator with air, mount a gauge to one port air in the other, center open and bring the pressure up until it opens the center. If it does then set it where it needs to be and put it back on. Run the hose like I suggested to validate the setting. Also try pressurizing the return line and see if (a) you can get air through it and (b) what kind of pressure it takes.

This is the FDM that was in the tank when you bought BB isn't it? Could be the valve is stuck and just needs a good shot of pressure to pop it loose.

Oh, I'm sure I've already overthought it. And I'm not done!

No, this FDM is a brand new one from Spectra. It and the tank were purchased separately but are the right ones for a '95 F350. The rear tank and FDM came as a unit. So everything is new, including the lines and all of the connections.

I'm with you on testing the regulator. But I'm not on pressure on the return line. I would think that both FDM's would have their returns closed until power was on them. Else you'd return fuel to the wrong tank. Yes?

[85lebaront2]

Oh, I'm sure I've already overthought it. And I'm not done!

No, this FDM is a brand new one from Spectra. It and the tank were purchased separately but are the right ones for a '95 F350. The rear tank and FDM came as a unit. So everything is new, including the lines and all of the connections.

I'm with you on testing the regulator. But I'm not on pressure on the return line. I would think that both FDM's would have their returns closed until power was on them. Else you'd return fuel to the wrong tank. Yes?

With the pump running and the pressure regulator return run to the filler neck, that is when I would try pressure on the return line. It may be that it takes 11-12 psi to open the return check valve.

There was a returnless regulator I used to use at Preston on the AMC Pacers before AMC issued a recall for hot start problems caused by the underhood heat. The fuel line from the pump to the Carter YF would develop so much pressure it would overpower the float needle and seat and flood the intake. The regulator had a glass lower and a dial to set the pressure, I do not remember the brand but it was a cheap part that worked perfectly.

Maybe our parts research department can find one.

[Gary Lewis]

With the pump running and the pressure regulator return run to the filler neck, that is when I would try pressure on the return line. It may be that it takes 11-12 psi to open the return check valve.

There was a returnless regulator I used to use at Preston on the AMC Pacers before AMC issued a recall for hot start problems caused by the underhood heat. The fuel line from the pump to the Carter YF would develop so much pressure it would overpower the float needle and seat and flood the intake. The regulator had a glass lower and a dial to set the pressure, I do not remember the brand but it was a cheap part that worked perfectly.

Maybe our parts research department can find one.

Yes! What you said reminded me of the section of the manuals you and I posted. Mine is OCR'd so I was easily able to copy the text, which says:

The shuttle selector valve opens the return line to the tank and the return flow is directed to the appropriate tank on vehicles equipped with dual tanks.

So, the FDM could easily be the problem as if the shuttle selector valve doesn't open the regulator can't work. And running the return into the filler neck or even into the 5 gallon gas can would prove that. However, I'd have to pull the line. I wonder if I couldn't put 5 gallons of gas in the rear tank and try it? Surely I wouldn't have a problem with both FDMs?

As for the regulator you mentioned, I don't think that will work. I need to be recirculating the fuel to keep it cool, so need a return-style regulator. Besides, these pumps put out ~40 psi and Holley says that's too much for their original regulators, so might be for the one you are thinking of.

[85lebaront2]

Yes! What you said reminded me of the section of the manuals you and I posted. Mine is OCR'd so I was easily able to copy the text, which says:

The shuttle selector valve opens the return line to the tank and the return flow is directed to the appropriate tank on vehicles equipped with dual tanks.

So, the FDM could easily be the problem as if the shuttle selector valve doesn't open the regulator can't work. And running the return into the filler neck or even into the 5 gallon gas can would prove that. However, I'd have to pull the line. I wonder if I couldn't put 5 gallons of gas in the rear tank and try it? Surely I wouldn't have a problem with both FDMs?

As for the regulator you mentioned, I don't think that will work. I need to be recirculating the fuel to keep it cool, so need a return-style regulator. Besides, these pumps put out ~40 psi and Holley says that's too much for their original regulators, so might be for the one you are thinking of.

I was more thinking of it as being used beyond the present regulator to hold the pressure to the carburetor where it needs to be with the return still operational.