For those of you with 60 lb injectors....

[juno]

..did you have to upgrade the FMU???? Can it handle the extra current draw?

[shakes_26]

no fmu upgrade required, short of the tune. Its no longer 1989!!!

[MarauderMark]

no fmu upgrade required, short of the tune. Its no longer 1989!!!
wtf is fmu?

[Rider90]

wtf is fmu?
omg wtf lmao brb...

[shakes_26]

Uh an FMU would be a Fuel Management Unit, its basically a pressure regulator, but its job is really related to boost
The stock fuel pressure regulator stops at atmospheric, therefore would stop giving additional fuel in boost conditions, thereby going lean. The FMU, in sorts piggybacks the fuel pressure regulator and is actuated by boost, to continue adding more fuel pressure as more boost is added.

This of course is applicable to return style fuel systems, as our cars use a returnless application, it is not needed, and thereby controlled fuel pressure is controlled by the PCM.







wtf is fmu?

[MarauderMark]

Uh an FMU would be a Fuel Management Unit, its basically a pressure regulator, but its job is really related to boost
The stock fuel pressure regulator stops at atmospheric, therefore would stop giving additional fuel in boost conditions, thereby going lean. The FMU, in sorts piggybacks the fuel pressure regulator and is actuated by boost, to continue adding more fuel pressure as more boost is added.

This of course is applicable to return style fuel systems, as our cars use a returnless application, it is not needed, and thereby controlled fuel pressure is controlled by the PCM.
Thank you for the info. i didnt know this.Well then what is the (Electronic fuel management system?) box thing that is connected in our trucks on the left side under the carpeting that has a plug.Cause this little square box thing i had changed to a modified one.if it is one in the same.

[shakes_26]

That would be the fuel pump driver module. Thats what takes the signal from the PCM and then drives the fuel pump.

I don't see what a modified one would buy you. Unless its basically another way to achieve the Boost a pump type function, but constantly on, unless it has extra wiring to it for a boost switch.

Ah I see you have the twin focus pumps, I remember there was something with those a vendor at the NMRA's was mentioning needed to be changed/done, maybe thats it?

[MarauderMark]

That would be the fuel pump driver module.
Thank you sir for your information it was greatly appreciated.:up:

[FordNut]

That would be the FPDM (Fuel Pump Driver Module) which has power transistors to drive the signal to the fuel pumps. The current draw from twin Cobra pumps is not enough to overload the transistors so it's not really necessary to upgrade the FPDM. Twin Focus or twin Aviator pumps draw more current and will overload the transistors, causing the FPDM to overheat and shutdown, in turn causing a lean condition and possibly blowing the motor. The upgraded FPDM has different driver transistors which can handle the extra current. It is also common to upgrade the wiring from the FPDM to the pumps by connecting a second pair of wires in parallel to the stock ones. This is what a lot of the 'stang guys do if they are running high horsepower but want to retain the returnless fuel system. The latest returnless fuel system mod is to replace the twin Cobra pumps with twin Ford GT Supercar pumps, which flow more than Cobra, Aviator, or Focus pumps but draw less current than the Aviator or Focus pumps.

[juno]

I came across a discussion somewhere involving the limit on current drawn by the injectors. I could not recall if they were 60's or bigger, but they had to ugrade the FPDM or FMU or whatever you wish to call it. I could not find that discussion again and I know some of you have 60's so I wanted to make sure before I placed my order.

And I just ordered my GT40 pump from Ray the Dealer. :cool:

Check out the chart. Someone might want to sticky this somewhere.

[shakes_26]

interesting, what do the GT pumps cost $$? Is the twin pump setup stock, or a 3rd party/ diy manufactured assembly?

Brian,

I suspected as much, anything you don't know?

[juno]

It is a ford part # pfb81 for a single pump. So far everything I hear is plug and play. And it is cheaper then a Focus SVT pump. Can I post Ray the Dealer's price?
I think the svt Focus costs more because of the internal bypass or blow-off at 85#.

[MarauderMark]

Twin Focus or twin Aviator pumps draw more current and will overload the transistors, causing the FPDM to overheat and shutdown, in turn causing a lean condition and possibly blowing the motor.
How can one tell the difference if it is modified to one that is stock? Or check for failure.

[MikesMerc]

All you need to add when you go with the 60lb injectors is the "adapter" connectors for each injector. The stock connectors will not plug directly into the 60s. You'll obviously need 8, one for each injector. They are about $10 each.

[FordNut]

All you need to add when you go with the 60lb injectors is the "adapter" connectors for each injector. The stock connectors will not plug directly into the 60s. You'll obviously need 8, one for each injector. They are about $10 each.
Yep, for the injector upgrade that's all that is needed. But if the car is setup to really push the 60's, the rest of the fuel system needs upgrades too.




Twin Focus or twin Aviator pumps draw more current and will overload the transistors, causing the FPDM to overheat and shutdown, in turn causing a lean condition and possibly blowing the motor.
How can one tell the difference if it is modified to one that is stock? Or check for failure.
Unless you sent it off to be modified, it probably hasn't been. If you sent it to Mark Chiappetta (sp?) also known as mjchip on some other forums, it's modified but otherwise it's not. As stated previously, the stock FPDM and/or BAP is fine for twin Cobra pumps. I believe a single Focus SVT pump or single Aviator pump or single GT Supercar pump will be fine with the stock FPDM and/or BAP also. I dunno how to tell if one has failed, not sure if they go into thermal overload and stop working until they cool down then start working again or what.


It is a ford part # pfb81 for a single pump. So far everything I hear is plug and play. And it is cheaper then a Focus SVT pump. Can I post Ray the Dealer's price?
I think the svt Focus costs more because of the internal bypass or blow-off at 85#.
That's not the full part number I ordered, it was 4G7Z-9A407-CA. Not exactly plug and play, the tubing is different as well as the wiring connectors. The wiring connectors are individual slip-fit connectors to go onto lugs on the pumps. The pumps come with a plastic housing which is easily broken off the pump, leaving a pump which is the same size as the standard (and Cobra) pumps. Not sure what to do about the hose connectors, I haven't put them in yet.


interesting, what do the GT pumps cost $$? Is the twin pump setup stock, or a 3rd party/ diy manufactured assembly?

Brian,

I suspected as much, anything you don't know?
I believe the pumps are around $80-$90 each. The problem is that you first need the twin Cobra pump setup which is basically made by welding the pump mounts from the Cobra onto the gas tank flange from a Marauder. Sold by DR. Then you have a place to put the GT pumps. The setup is just now being finalized for marketing to the 'stang guys, check over at modularfords.com for details on the setup and the 800+ RWHP twin turbo car running it. I doubt it will ever be offered as a kit for the MM, probably a DIY.

Still learning...

[juno]

That's not the full part number I ordered, it was 4G7Z-9A407-CA. Not exactly plug and play, the tubing is different as well as the wiring connectors. The wiring connectors are individual slip-fit connectors to go onto lugs on the pumps. The pumps come with a plastic housing which is easily broken off the pump, leaving a pump which is the same size as the standard (and Cobra) pumps. Not sure what to do about the hose connectors, I haven't put them in yet.


I believe the pumps are around $80-$90 each.

That part number worked for Ray and it worked on Rock Auto and Motorcraft.

Ray's price was $79 plus shipping til the end of April. I think there is a price hike coming.

How are the hose connectors different?

DO you have a pic? I would like to see the lugs also.

[FordNut]

That part number worked for Ray and it worked on Rock Auto and Motorcraft.

Ray's price was $79 plus shipping til the end of April. I think there is a price hike coming.

How are the hose connectors different?

DO you have a pic? I would like to see the lugs also.
I'll try to post a pic tomorrow evening.

[FordNut]

Here's the fuel pump without the plastic housing:

http://www.mercurymarauder.net/showcase/files/5/1/8/DSC01275.JPG

[FordNut]

That part number worked for Ray and it worked on Rock Auto and Motorcraft.

Ray's price was $79 plus shipping til the end of April. I think there is a price hike coming.

How are the hose connectors different?

DO you have a pic? I would like to see the lugs also.
Pic posted, check out the wiring lugs and hose connection.

As for the part numbers, both PFB-81 and 4G7Z-9A407-CA are on the box. I have experienced parts orders where the short number got me the wrong part but the long number got me the right one. That is because the short number is SOMETIMES used for two totally different parts. The long number will always get you the right part. In this particular case, either number works.