Running a return system on s returnless car? come on down

[jaa55]

I'm using a 06 Crown Vic driveline in my F100 and I need a solution for my fuel system. I'm going to use the factory F100 tank so using a hat form the CV is out. I'm going to run an inline fuel pump.

For those of you that have converted to return, did you tune afterwards? I'm assuming the computer is going to throw codes without the FPDM. I'd rather wait to tune until next year when I'm more than likely going 4 valve and plus I'm on a budget to be running by spring time.

A company called fuelab makes an inline that can work with a pulse modulated returnless system.
The pump has a three post connection 12v/ground/speed control post.

The speed control post accepts 0-12v pulse modulated signal that I could use from my factory Crown Vic FPDM. Anyone ever used one?

[Rodeheaver's]

Yes, when converting to a return system you have to correct it in the tune. A dead head system uses a modulated pump and varies the pump voltage to keep the commanded pressure at the rail.

[jaa55]

Ever use a fuelab inline pulse modulated pump or similar Tim? Obviously the factory pump is two wire.... One 0-12v pulse modulated and ground. I see no difference in running this aftermarket pump with the three post connection....it's just the first I've seen it. Every other aftermarket variable speed pump I've used have just been in tank two wire style. All i should have to do it use my two factory wires from the FPDM for ground and speed control and then run a separate 12v switched off and on with the ignition

[yeahloh95]

could you remount the factory pump ? in a underhood fuel cell then feed that cell from the stock tank like the edelbrock kit does ?

[Stangman701]

I think you'll probably have troubles with that inline pump from a tuning standpoint as well. In a returnless setup the tune is much more affected by the pump than in a return style. In the return style the engine doesn't really care what the fuel pump is doing so long as it can supply enough fuel to maintain the set pressure at the regulator. On the returnless style each pump's "personality" has to be adjusted for in the tune. My tuner and I were fighting this issue when I was trying to use one of the newer 340LPH pumps in a returnless setup on my old cobra. It's not so bad when you're using a Ford pump(Cobra, SVT Focus, Ford GT, etc.) because Ford has spent a lot of time mapping out their characteristics and the tune can easily be adjusted for them.

Troy's idea with the underhood fuel cell and stock pump would probably be the easiest and most reliable way to get yourself up and running if you need to stay returnless. In the long run though I'd say it would be worth going a little over budget now to save money on the overall build to go ahead and build a good return system.

[Rodeheaver's]

Ever use a fuelab inline pulse modulated pump or similar Tim? Obviously the factory pump is two wire.... One 0-12v pulse modulated and ground. I see no difference in running this aftermarket pump with the three post connection....it's just the first I've seen it. Every other aftermarket variable speed pump I've used have just been in tank two wire style. All i should have to do it use my two factory wires from the FPDM for ground and speed control and then run a separate 12v switched off and on with the ignition
Its hard for me to say how it would work ive never done it but in theory it should work. Try it...

[jaa55]

I think you'll probably have troubles with that inline pump from a tuning standpoint as well. In a returnless setup the tune is much more affected by the pump than in a return style. In the return style the engine doesn't really care what the fuel pump is doing so long as it can supply enough fuel to maintain the set pressure at the regulator. On the returnless style each pump's "personality" has to be adjusted for in the tune. My tuner and I were fighting this issue when I was trying to use one of the newer 340LPH pumps in a returnless setup on my old cobra. It's not so bad when you're using a Ford pump(Cobra, SVT Focus, Ford GT, etc.) because Ford has spent a lot of time mapping out their characteristics and the tune can easily be adjusted for them.

Troy's idea with the underhood fuel cell and stock pump would probably be the easiest and most reliable way to get yourself up and running if you need to stay returnless. In the long run though I'd say it would be worth going a little over budget now to save money on the overall build to go ahead and build a good return system.

Tuning in the future was definitely one of my concerns running the pulse modulated inline.
This entire wiring and computer from the p71 is giving me concerns. If I go 4 valve in the near future I'm worried about what I will do with the drive by wire. I don't know if throttle body swaps on this computer will work well. The only bonus to running this system is the p71s don't have PATS.

[Rodeheaver's]

Keep in mind we can turnoff patts in any ecu.

[jaa55]

Only problem is I own this one already, changing ecu and wiring right now will incur some large costs.

Drugs are a cheaper hobby

[rob2407]

just kind of did this. Own a 96 GT. the stock 96 fuel system is a return style system. i got a 15k mile engine from a 2003 Saleen 2v with a blower on it which would have used a return less system. No ecu change, but some plumbing changing, and working out pretty good! Actually called Tim, he recommended a bigger pump, which I am working on. Gonna need a tune here soon also. Just my .2
Hope it's working out well!!

[jaa55]

I'm almost ready to start it, I ended up going aftermarket regulator and pump. Ford FPDM supply's 12v all the time and changes the pulse width of the ground to increase/decrease speed. The pump I bought did the opposite, it uses PWM on the positive side. So I bought their regulator to control the pump.