Return style wiring HOW TO allowing OE type fuel pump actuation

[Tims97SVT]

Way ahead of you...

No it cant, hence why I'm posting in here.



Maybe I'm not being clear enough with my intentions. I want my return fuel setup to behave like a foxbody, or other factory return style cars, not just run pumps full time with the key on like they do now with the green/yellow wire tapped for my relay signal.

I'm guessing this is what the op is trying to acomplish also?



From what I'm reading here it looks like there's no such pinout on the returnless style cars.

Got ya, got ya. Where all getting mixed up in this thread I believe lol. Being you were talking about power, I figured you where just looking for a power point, not for it to act like a fox. :beer:

It can be done, maybe not threw the PCM. Just going to take a little thinking.

 

[Tims97SVT]

Thought: I know I've see guys say when you switch to return you have to switch something in the PCM to return from returnless for the tune. What are we changing here?

 

[gt347mustang]

Thought: I know I've see guys say when you switch to return you have to switch something in the PCM to return from returnless for the tune. What are we changing here?

My tuner couldn't figure it out. He was using Diablo.

 

[Tims97SVT]

My tuner couldn't figure it out. He was using Diablo.

Who's tuning your car?

 

[black 10th vert]

Thought: I know I've see guys say when you switch to return you have to switch something in the PCM to return from returnless for the tune. What are we changing here?

From what I understand the only thing that gets changed in the tune itself is that the FPDM gets turned off, since it will throw a code otherwise.

This thread is of great interest to me since part of my winter plans include going return. I planned to just buy the correct plug to fit the FPDM harness, so that I could have a clean way to trigger the relays without cutting up the factory harness. I hadn't really considered the implication of having the pumps run full time, but why are you guys bothered by that? You need the pumps to run whenever the car is running anyway, so the only downside is that you will hear the pumps running when you key it to "on" without starting the car. Beyond that, I can't think of any reason for it to be any different. Am I missing something here?:??:

 

[Tims97SVT]

From what I understand the only thing that gets changed in the tune itself is that the FPDM gets turned off, since it will throw a code otherwise.

This thread is of great interest to me since part of my winter plans include going return. I planned to just buy the correct plug to fit the FPDM harness, so that I could have a clean way to trigger the relays without cutting up the factory harness. I hadn't really considered the implication of having the pumps run full time, but why are you guys bothered by that? You need the pumps to run whenever the car is running anyway, so the only downside is that you will hear the pumps running when you key it to "on" without starting the car. Beyond that, I can't think of any reason for it to be any different. Am I missing something here?:??:

Just for the sheer fact that whenever you turn the key on the pumps are on. Ie loading tunes and stuff. More of an annoyance then anything I guess.

 

[black 10th vert]

Just for the sheer fact that whenever you turn the key on the pumps are on. Ie loading tunes and stuff. More of an annoyance then anything I guess.

I see, that makes sense. Hopefully someone can figure out a method to correct this. I had a setup on my '65 Cobra replica where I had an electric pump that ran full time to supply the dual quads, in a returnless setup. It worked great, and was never an issue with them running all the time, because I didn't have a reason (like loading tunes) to ever have the key on for more than priming the line before pushing the start button. I forgot about having to keep the key on for loading tunes...

 

[MalcolmV8]

From what I understand the only thing that gets changed in the tune itself is that the FPDM gets turned off, since it will throw a code otherwise.

This thread is of great interest to me since part of my winter plans include going return. I planned to just buy the correct plug to fit the FPDM harness, so that I could have a clean way to trigger the relays without cutting up the factory harness. I hadn't really considered the implication of having the pumps run full time, but why are you guys bothered by that? You need the pumps to run whenever the car is running anyway, so the only downside is that you will hear the pumps running when you key it to "on" without starting the car. Beyond that, I can't think of any reason for it to be any different. Am I missing something here?:??:

yes more annoying than anything. Examples sited above such as loading tunes, or when you have the key on and maybe troubleshooting something under the hood etc. Or how about you stop at a sonic for a second and it's kinda cold out so you turn your key on so the blower motor will come on so you can blow some warm air in for a few. Just general stuff like that. It sucks having those pumps come on, they are loud enough to hear (my walbro 400s) and the power drain on the battery is pretty high.
Heck have you noticed when you go to get an alignment at a tire shop even they leave the key on all the way to make sure the steering is unlocked. Well they take so long my wideband drained the battery and they had to jump it. Second time around I had to specifically ask to keep the key back one click so the wideband was off. Same deal with the pumps.

Again not a big issue, just one of those nice touches to make the car a little more OEM and factory like while having a modded monster

 

[04sleeper]

This thread is of great interest to me since part of my winter plans include going return. I planned to just buy the correct plug to fit the FPDM harness, so that I could have a clean way to trigger the relays without cutting up the factory harness. I hadn't really considered the implication of having the pumps run full time, but why are you guys bothered by that? You need the pumps to run whenever the car is running anyway, so the only downside is that you will hear the pumps running when you key it to "on" without starting the car. Beyond that, I can't think of any reason for it to be any different. Am I missing something here?:??:

That's about it. Nothing really negative.

Just for the sheer fact that whenever you turn the key on the pumps are on. Ie loading tunes and stuff. More of an annoyance then anything I guess.

You are ALWAYS supposed to disable the pumps and fan whe loading a tune.

 

[MalcolmV8]

You are ALWAYS supposed to disable the pumps and fan whe loading a tune.

I'd never heard that before. What happens if you load a tune with the fan or pumps enabled?

 

[sn94cobra]

You could install a timer for key on position then configure a latching relay setup for the start position.
Automotive Time-Delay Relay

I have thought about doing this but after having my return setup for two years I find it not as annoying as I originally thought.

 

[Wicked46]

Malcolm - I believe SVT GI has the solution I mentioned in your build thread. If you tap into the FPDM with the hot wire on your relay to the wire he mentions, your pumps will prime like stock and shut off after a few seconds.... You need to enable the FPDM in the tune to run 100%. This is coming straight from my tuner (Justin at VMP)

 

[black 10th vert]

Malcolm - I believe SVT GI has the solution I mentioned in your build thread. If you tap into the FPDM with the hot wire on your relay to the wire he mentions, your pumps will prime like stock and shut off after a few seconds.... You need to enable the FPDM in the tune to run 100%. This is coming straight from my tuner (Justin at VMP)

Wow, this is the first time I have ever read of a return being set up this way! Can someone post a wiring diagram of what wires, and where in the harness to tap into them? This sounds like a great solution, especially since the hardware is already there instead of adding even more relays and crap that is prone to failing. Usually every thread detailing the install of return systems recommend deleting the FPDM, and turning it off in the tune.

 

[encasedmetal]

Thought: I know I've see guys say when you switch to return you have to switch something in the PCM to return from returnless for the tune. What are we changing here?

the style of pump used in the tune

 

[encasedmetal]

I'd never heard that before. What happens if you load a tune with the fan or pumps enabled?

you can potentially drain your battery while loading the tune by running the fans and pumps- if your battery dies while loading a tune- your ECU is done, and you will need a new one.

BTW_ OP- simply use a razor blade to unsheath a section of the green w/yellow stripe wire on the PATS module- and your pumps will be wired in just like stock.

 

[sn94cobra]

BTW_ OP- simply use a razor blade to unsheath a section of the green w/yellow stripe wire on the PATS module- and your pumps will be wired in just like stock.

Help me understand this more. Are your referring to the pats module or fpdm?

 

[MalcolmV8]

Malcolm - I believe SVT GI has the solution I mentioned in your build thread. If you tap into the FPDM with the hot wire on your relay to the wire he mentions, your pumps will prime like stock and shut off after a few seconds.... You need to enable the FPDM in the tune to run 100%. This is coming straight from my tuner (Justin at VMP)

BTW_ OP- simply use a razor blade to unsheath a section of the green w/yellow stripe wire on the PATS module- and your pumps will be wired in just like stock.

I assume you mean the FPDM as that's what everyone else is saying.

I don't see how this would work, I need more details. The green with yellow stripe wire at the FPDM (pin 9) is what I'm using now. It's nothing more than relay switched power for key on/start position. There's no way to make it prime from that.
Now the white wire with red stripe (pin 1) is the signal wire from the ECC to the FPDM and it appears to provide a signal at key on just to prime and then go off. However it's a very low current signal just for the FPDM to sense. It's not strong enough to drive a relay. I've tried.

Is there anyone who actually has this working and can comment?

 

[sn94cobra]

I assume you mean the FPDM as that's what everyone else is saying.

I don't see how this would work, I need more details. The green with yellow stripe wire at the FPDM (pin 9) is what I'm using now. It's nothing more than relay switched power for key on/start position. There's no way to make it prime from that.
Now the white wire with red stripe (pin 1) is the signal wire from the ECC to the FPDM and it appears to provide a signal at key on just to prime and then go off. However it's a very low current signal just for the FPDM to sense. It's not strong enough to drive a relay. I've tried.

Is there anyone who actually has this working and can comment?

Does the wire on pin 1 have the voltage go away when key is on the run position after a few sec?
If so then it possible to get this to work.

 

[MalcolmV8]

Does the wire on pin 1 have the voltage go away when key is on the run position after a few sec?
If so then it possible to get this to work.

It does if you put a digital multimeter on it. However as I said it's a very low current signal only. Not strong enough to drive a relay.

I'm thinking of a new way to wire this.... I'm thinking the brown wire with pink stripe (pin 10) that normally would go directly to your fuel pumps, or one pump in a dual FPDM setup, could be used to drive the relay. I'll go in the garage and test my theory now.

 

[sn94cobra]

So pin as small voltage initially then goes away? If so maybe the fpdm can drive the relay as you are suggesting through the other wire?