Lethal's wiring upgrade without KB BAP...

WydOpen

New Member
Established Member
Joined
Aug 26, 2004
Messages
582
Location
Boise, ID and GoM Offshore
I had my car on the dyno on Monday and we saw dangerous drops in fuel pressure above I'd say 4,000 rpm's. It was dropping as low as 22 psi. The only thing I don't have installed is the wiring upgrade. I purchased it after leaving the dyno and started installing it today. The directions off your site is for wiring up a BAP with the kit and I am not running a BAP. Just looking for a little guidance on the install.

My current fuel system consists of...

- SD 60 lb injectors
- Fore fuel hat
- Dual GT pumps
- 8an feed line (returnless)
- Aeromotive 10 micron filter
- Fore Y-block leading into the rear of each fuel rail
- Fore rails
- Single Zone 5 Performance Stage 2 FPDM

I've attached the 8 gauge RED wire (instructions say black and also references it as yellow) to the power distribution box terminal via the ring terminal. I then mounted the 40 AMP AGU fuse holder in-line about 8-10" down from the power distribution box and routed the 8 gauge wire through the interior to the trunk.

Instructions say to splice the 8 gauge wire to the yellow (in my case green) wire coming off of (87) of the relay adapter. It then says to ground the white wire from (85) of the relay adapter to ground.

It then says to take the white or black wire from (86) of the relay adapter and splice it to the green/yellow wire of the FPDM. Instead of white or black, mine is actually red. That leaves me a center blue wire off of (87a) and black wire of of (30) that are just to be blanked off, correct?

Does this sound like the correct wiring procedure for my setup? Is there any wiring upgrade needed from the actual fore hat/pumps up to the FPDM? Is the only concern the power wire from the power distribution box? I'm hoping this setup is sufficient for my expected power level (600-650 rwhp).

Here is a pic of the relay adapter and wires...

p4010125.jpg
 

03cobra545

New Member
Established Member
Joined
Sep 5, 2006
Messages
85
Location
Indiana
bump. Let me know if the wire upgrade fixes it because I am having the same problems with the same fuel system. Above 4k rpms the rail pressure starts getting all sporadic. I ordered the wire upgrade and im hoping it fixes it...
 

WydOpen

New Member
Established Member
Joined
Aug 26, 2004
Messages
582
Location
Boise, ID and GoM Offshore
bump. Let me know if the wire upgrade fixes it because I am having the same problems with the same fuel system. Above 4k rpms the rail pressure starts getting all sporadic. I ordered the wire upgrade and im hoping it fixes it...

Are your fuel rails plumbed similar to mine? Meaning they are each fed from the rear via separate lines off the Y-block? Most other setups I've seen just accept the -8an line directly into the rear of the passenger side rail and crosses over the front of the blower into the front of the driver's side rail and then uses an end plug on the rear of the driver's rail.

I'm hoping this fixes my issues as well. I haven't received a reply, so I'm calling Lethal tomorrow and talk to a tech guy. I'll post up what I find out about the correct wiring procedure without using a BAP. My wire colors are all jacked and do not match the directions whatsoever. The relay adapter only plugs into the relay one of four ways, so I know I don't have it plugged incorrectly.
 

black03

Authorized Vendor
Authorized Vendor
Joined
Jul 4, 2002
Messages
8,247
Location
paradise
I had my car on the dyno on Monday and we saw dangerous drops in fuel pressure above I'd say 4,000 rpm's. It was dropping as low as 22 psi. The only thing I don't have installed is the wiring upgrade. I purchased it after leaving the dyno and started installing it today. The directions off your site is for wiring up a BAP with the kit and I am not running a BAP. Just looking for a little guidance on the install.

My current fuel system consists of...

- SD 60 lb injectors
- Fore fuel hat
- Dual GT pumps
- 8an feed line (returnless)
- Aeromotive 10 micron filter
- Fore Y-block leading into the rear of each fuel rail
- Fore rails
- Single Zone 5 Performance Stage 2 FPDM

I've attached the 8 gauge RED wire (instructions say black and also references it as yellow) to the power distribution box terminal via the ring terminal. I then mounted the 40 AMP AGU fuse holder in-line about 8-10" down from the power distribution box and routed the 8 gauge wire through the interior to the trunk.

Instructions say to splice the 8 gauge wire to the yellow (in my case green) wire coming off of (87) of the relay adapter. It then says to ground the white wire from (85) of the relay adapter to ground.

It then says to take the white or black wire from (86) of the relay adapter and splice it to the green/yellow wire of the FPDM. Instead of white or black, mine is actually red. That leaves me a center blue wire off of (87a) and black wire of of (30) that are just to be blanked off, correct?

Does this sound like the correct wiring procedure for my setup? Is there any wiring upgrade needed from the actual fore hat/pumps up to the FPDM? Is the only concern the power wire from the power distribution box? I'm hoping this setup is sufficient for my expected power level (600-650 rwhp).

Here is a pic of the relay adapter and wires...

p4010125.jpg


Red 8ga power wire goes to the Green wire on the relay harness.
White wire on the relay harness is ground.
Black wire on the relay harness goes to the Green/Yellow wire going into the FPDM (FPDM side)
Red wire on the relay harness goes to the Green/Yellow wire going away from the FPDM (Wire Side)

That's exactly how it should be setup in order for it to function properly.

Let us know if you have any other questions.

Thanks, Jared
 

03cobra545

New Member
Established Member
Joined
Sep 5, 2006
Messages
85
Location
Indiana
My fuel rail just accepts it on the passenger side with no y block, the wire upgrade from lethal should arrive today so I can install it and see if it helps
 
Last edited:

WydOpen

New Member
Established Member
Joined
Aug 26, 2004
Messages
582
Location
Boise, ID and GoM Offshore
Jared, thanks for the clarification! I'll get to that right after I swap out my low profile IRS bolts and tighten up the fuel line fittings. Also just swapped out the generic center caps with SVT caps.

I really hope this solves my fuel issues. I'm starting to get frustrated and I just want this car running correctly so I can start enjoying it.
 

WydOpen

New Member
Established Member
Joined
Aug 26, 2004
Messages
582
Location
Boise, ID and GoM Offshore
My fuel rail just accepts it on the passenger side with no y block, the wire upgrade from lethal should arrive today so I can install it and see if it helps

I'm sorry you're having the same problems as I'm facing, but glad to see I'm not alone on this. Also glad to see with a different fuel line arrangement we're seeing the same problem.

Let me know how you fare and I'll do the same.
 

03cobra545

New Member
Established Member
Joined
Sep 5, 2006
Messages
85
Location
Indiana
I'm sorry you're having the same problems as I'm facing, but glad to see I'm not alone on this. Also glad to see with a different fuel line arrangement we're seeing the same problem.

Let me know how you fare and I'll do the same.

Its frustrating isnt it?? If it is just a little power wire to the fpdm ill be annoyed that thats all it was but relieved at the same time lol. Mine just started doing it after I put my crusher on, had no problems before that. Must have been just enough to set it over the edge. Did u just start having this problem too?
 

WydOpen

New Member
Established Member
Joined
Aug 26, 2004
Messages
582
Location
Boise, ID and GoM Offshore
Its frustrating isnt it?? If it is just a little power wire to the fpdm ill be annoyed that thats all it was but relieved at the same time lol. Mine just started doing it after I put my crusher on, had no problems before that. Must have been just enough to set it over the edge. Did u just start having this problem too?

Yes it is. Just when I think I've got the solution to all my problems, something else comes up. I just want the motor running right so I can move on to the suspension.

Exactly, I'll be relieved if this is the solution to my problems. Yes, just started having this problem. I've been running around with a generic tune so I could break in my clutch. Went to get a solid dyno tune and found out about the fuel issue.

Good luck! :beer:
 

Gossioii6

New Member
Established Member
Joined
Mar 6, 2009
Messages
6
Location
1
this is very useful

Wow, this is very useful.. Thanks for sharing this and hoping I could implement it too.
 

sonicmach1

Active Member
Established Member
Joined
Jul 30, 2008
Messages
858
Location
IL
Dual FPDMs

Can anyone (or Lethal) send me the dual FPDM kit installation instructions to:
sonicmach1@gmail dot com (just replace the dot with a .)

If there are Fore hat instructions as well, I would also appreciate them.

I am ordering a similar fuel system and would like to read them beforehand.

Thank you!
 

sonicmach1

Active Member
Established Member
Joined
Jul 30, 2008
Messages
858
Location
IL
Does anyone have these instructions available? I would appreciate it. Thank you.
 

black03

Authorized Vendor
Authorized Vendor
Joined
Jul 4, 2002
Messages
8,247
Location
paradise
Does anyone have these instructions available? I would appreciate it. Thank you.

Here's the link to our technical documents section which contains the wiring instructions if you're using a BAP. If you're not using a BAP the instructions are basically the same but you'll take the BAP out of the mix.
http://www.lethalperformance.com/technical-documents-page-2.html

So with no BAP in place you'll be running the fused 8ga power wire from the battery to the trunk. Using the relay socket that we supply you' attach the 8ga wire to the green wire on the relay. The white wire on the relay is ground so you'll ground that to the chassis where the FPDM is ground. The center blue wire on the socket isn't used. The you'll want to find the green/yellow wire coming off the FPDM. You're going to cut that wire about 4" from the FPDM. Now connect the black wire on the relay socket to the green/yellow wire FPDM side and then the red wire on the relay socket to the green/yellow wire wireside.

That's it.

Let me know if you have any other questions.

11:31PM EST and still rockin!!! WOOT!!:rockon::rockon:
 

sonicmach1

Active Member
Established Member
Joined
Jul 30, 2008
Messages
858
Location
IL
Thank you for the help.

Here's the link to our technical documents section which contains the wiring instructions if you're using a BAP. If you're not using a BAP the instructions are basically the same but you'll take the BAP out of the mix.
Technical Documents : Lethal Performance, Performance parts for Ford Mustangs

So with no BAP in place you'll be running the fused 8ga power wire from the battery to the trunk. Using the relay socket that we supply you' attach the 8ga wire to the green wire on the relay. The white wire on the relay is ground so you'll ground that to the chassis where the FPDM is ground. The center blue wire on the socket isn't used. The you'll want to find the green/yellow wire coming off the FPDM. You're going to cut that wire about 4" from the FPDM. Now connect the black wire on the relay socket to the green/yellow wire FPDM side and then the red wire on the relay socket to the green/yellow wire wireside.

That's it.

Let me know if you have any other questions.

11:31PM EST and still rockin!!! WOOT!!:rockon::rockon:
 

Users who are viewing this thread



Top