Big Blue's Transformation

[Gary Lewis]

Disconnect the return line from the regulator and plug the end for safety. Connect an extra piece of hose to the regulator output and run it around to the filler neck of the tank you are using. First if no fuel comes from the regulator you have determined you are plumbed backwards. If it does and you can now control the pressure then something is restricting the return, possibly the shuttle valve in the pump module.

Does the pump module you are using still have the recall valve on it? That will guarantee that the flow direction is out from the tank leaving the other nipple as the return. I would also try low pressure air into the tank return to make sure it isn't obstructed. For a refresher, here are the two pictures of the 1993 FDM.

Bill - Hadn't seen your response. But I wonder if I have the equivalent of that in my '95 FSM? If so, I want to document that on the site. I'm going out to the shop to look.....

Anyway, I don't want to disconnect the rubber hoses from the regulator if I don't have to do so. That is a pain - in several ways. I'm sporting a pretty good scrape from when the hose finally let go today. So I'd prefer to do my test since it is so easy to disconnect the fuel filter. Just wrap the ends with shop towels and blip the pump. One towel will get wet. Won't that work?

[ArdWrknTrk]

Are you saying to pressurize the tank via the cap or the vent and see where it comes out? Would the fuel delivery assembly work that way?

I was thinking I'd pull the fuel filter, which is easily done via the disconnects, and wrap the end of the lines in shop towels. Turn the pump on briefly and see which one gets wet. If it is what I thought was coming from the tank then I had the supply sussed correctly. If it is the one coming from the regulator then I have them backward.

Won't get to this until Sunday as we are going to a funeral tomorrow. But wouldn't that be a positive answer to the question? And not likely to get gas everywhere?

No, not pressurizing the tank.

Sending pressure through the regulator...

But the filter solution seems promising.

More I see of this the more I appreciate that I have a purely mechanical system.

(Though, I realize that won't help your future EFI plans)

 

[85lebaront2]

Are you saying to pressurize the tank via the cap or the vent and see where it comes out? Would the fuel delivery assembly work that way?

I was thinking I'd pull the fuel filter, which is easily done via the disconnects, and wrap the end of the lines in shop towels. Turn the pump on briefly and see which one gets wet. If it is what I thought was coming from the tank then I had the supply sussed correctly. If it is the one coming from the regulator then I have them backward.

Won't get to this until Sunday as we are going to a funeral tomorrow. But wouldn't that be a positive answer to the question? And not likely to get gas everywhere?

I was referring to pressurize the return line once you have verified correct flow. For the initial I said remove the "return" from the regulator and plug the end in case it is backwards. take a new piece of hose from the regulator and run it to the filler neck for the tank you are using (cap off obviously) if you have return flow, now adjust the regulator for the correct pressure. If no return flow then you must be plumbed backwards and will need to correct it, but you can break in the cam with the return secured in the filler neck and get that major item ticked off your list.

If you have correct flow, then see if you can pressurize the return line (from the way I read it the pump has to be running) and get flow back to the tank. It may be that the return valve takes 10-12 psi to open it, I don't know as I never bothered to check, I know I get 39-42 psi engine off on Darth and 55 on the Chrysler.

[Gary Lewis]

I was referring to pressurize the return line once you have verified correct flow. For the initial I said remove the "return" from the regulator and plug the end in case it is backwards. take a new piece of hose from the regulator and run it to the filler neck for the tank you are using (cap off obviously) if you have return flow, now adjust the regulator for the correct pressure. If no return flow then you must be plumbed backwards and will need to correct it, but you can break in the cam with the return secured in the filler neck and get that major item ticked off your list.If you have correct flow, then see if you can pressurize the return line (from the way I read it the pump has to be running) and get flow back to the tank. It may be that the return valve takes 10-12 psi to open it, I don't know as I never bothered to check, I know I get 39-42 psi engine off on Darth and 55 on the Chrysler.

Ok, we don't have to leave until 11:00 tomorrow so I think I'm going to pull the fuel filter and do that test. And if it is backwards then I have two choices:

 

1. Swap the hoses, turn the filter around, and filter on the return

 

Cross the lines over at the fuel filter. I think I can do that fairly easily by adding connectors there, and that would mean I won't have to pull the rubber hoses off the regulator. And it would mean I'd filter on the supply side.

 

I think I like scenario #2 better. Thoughts?

 

However, Bill's question about the TSB check valves reminds me - they were on the larger 3/8" connections. Are they on the supply side or the return?

 

And, for the record, here's the section on the 1995 FSM. Looks a lot like what you posted, Bill. Thanks.

 

[ArdWrknTrk]

Ok, we don't have to leave until 11:00 tomorrow so I think I'm going to pull the fuel filter and do that test. And if it is backwards then I have two choices:

 

1. Swap the hoses, turn the filter around, and filter on the return

 

Cross the lines over at the fuel filter. I think I can do that fairly easily by adding connectors there, and that would mean I won't have to pull the rubber hoses off the regulator. And it would mean I'd filter on the supply side.

 

I think I like scenario #2 better. Thoughts?

 

However, Bill's question about the TSB check valves reminds me - they were on the larger 3/8" connections. Are they on the supply side or the return?

 

And, for the record, here's the section on the 1995 FSM. Looks a lot like what you posted, Bill. Thanks.

 

They're on the supply.The problem is that one supply pumps into the other (if the original check valve doesn't seat)I think I'd rather make the hoses right, at the tank than switch them at the filter, but that's just me...

[Gary Lewis]

They're on the supply.

The problem is that one supply pumps into the other (if the original check valve doesn't seat)

I think I'd rather make the hoses right, at the tank than switch them at the filter, but that's just me...

They are all 3/8" hoses, so there's really nothing wrong with it. The only thing is which line the fuel filter is in and where they connect to the regulator.

And if the TSB check valves were on the supply then I have it plumbed correctly, which I hope to prove in the morning.

[Gary Lewis]

They are all 3/8" hoses, so there's really nothing wrong with it. The only thing is which line the fuel filter is in and where they connect to the regulator.

And if the TSB check valves were on the supply then I have it plumbed correctly, which I hope to prove in the morning.

I think I see the issue. In this pic the top line is the return.

And in this pic the return is therefore the one that goes up on top on the right. But, I was thinking that was the supply. So that line is going to the inlet of the regulator, but it is actually the return. I'll prove that tomorrow. But fixing it isn't as easy as removing the hoses from the regulator. If I'm right the supply has a 5/16" connector and the return has a 3/8". So when I go to EFI they'd be wrong again.

I'll need to make the change down by the fuel filter and cross over there.

 

[ArdWrknTrk]

I think I see the issue. In this pic the top line is the return.

And in this pic the return is therefore the one that goes up on top on the right. But, I was thinking that was the supply. So that line is going to the inlet of the regulator, but it is actually the return. I'll prove that tomorrow. But fixing it isn't as easy as removing the hoses from the regulator. If I'm right the supply has a 5/16" connector and the return has a 3/8". So when I go to EFI they'd be wrong again.

I'll need to make the change down by the fuel filter and cross over there.

So, you accidenty plumbed the regulator backwards?

Or you plumbed the filter backwards?

Seems like it's a lot easier to fix on the frame rail than behind the engine, but that's just me....

[Gary Lewis]

So, you accidenty plumbed the regulator backwards?

Or you plumbed the filter backwards?

Seems like it's a lot easier to fix on the frame rail than behind the engine, but that's just me....

Ok, in the almost light of day I'm pretty sure I know what the problem is. I'll go out and confirm it later, but here 'tis.

The hoses are fine up until they go onto the back of the transmission. To that point I'd used the convention of supply on the bottom and return on top. But at the stay to the frame they got reversed and I put the 3/8" connector on the return and 5/16" on the supply..

I could swap the rubber hoses at the regulator, but when I go to EFI I'd have the problem again because the 3/8" pigtail is the supply and the 5/16" is the return.

So what I need to do is, on the frame rail as you said, cross them over. I already have 5/16" connectors in the supply line for the fuel filter. So if I put connectors in the return I can swap - probably easily.

The only issue is that the filter supplies the male component of the connection, so since I'll only have one filter I need to put a 3/8" hose barb/male 5/16" fitting in the return awa a 5/16 female. I have the female connector, but I'm having a hard time finding that male connector.

 

[ArdWrknTrk]

Ok, in the almost light of day I'm pretty sure I know what the problem is. I'll go out and confirm it later, but here 'tis.

The hoses are fine up until they go onto the back of the transmission. To that point I'd used the convention of supply on the bottom and return on top. But at the stay to the frame they got reversed and I put the 3/8" connector on the return and 5/16" on the supply..

I could swap the rubber hoses at the regulator, but when I go to EFI I'd have the problem again because the 3/8" pigtail is the supply and the 5/16" is the return.

So what I need to do is, on the frame rail as you said, cross them over. I already have 5/16" connectors in the supply line for the fuel filter. So if I put connectors in the return I can swap - probably easily.

The only issue is that the filter supplies the male component of the connection, so since I'll only have one filter I need to put a 3/8" hose barb/male 5/16" fitting in the return awa a 5/16 female. I have the female connector, but I'm having a hard time finding that male connector.

3/8 barb to ?

The Ford garter type fuel connection, in 5/16?