2FAST4U

I got a walbro 400 fuel pump in my 2007 nnbs ccsb 5.3 vortec. I unfortunately didn't check for the "control box"by the spare tire but I will check.

Question is can I get away with just installing the pump or do I need to add a Hotwire kit? I will add a vet filter/regulator if I must. Like o keep it somewhat simple.

Anyone have any info that can help? Any way I can add a in tank regulator??

pics are much appreciated


* Oh and it is mostly stock but will get stage 2 heads,.650 springs,pushrods,cam with the DOD delete I am putting together. Then a 76mm and tune

mdwatts11

iTrader: (4)

The box is called the FPCM. There are different schools of thought on the Hotwire kit with the FPCM. Some even say the 400 is capable of variable voltage.

Anyway, here's a bump for you.

2FAST4U

I read that it had a internal regulator as well as variable voltage. However it then says to upgrade wiring due to the amps it pulls. But i can't hotwire and still have he FPCM.

I checked and do have the FPCM. I would buy the vet regulator/filter then have custom lines and fittings but I can't find any info on this at all.

Parts are on the way but I have my other truck down with brake issues. so desperate for a answer.

GXPJAY

Where did you check to see if you have the FPCM? I was told on my 07 NNBS I don't have a FPCM so I would like to check that.

05GMC4.8

It should be near/next to the spare tire under the bed as o.p. stated

2FAST4U

Yes ran out there late last night to check and there was that module with a ton of wires above the spare tire. I am assuming I have it based of the images of the FCPM I see online.

At this point I am installing it. I have been told it will work.

I think I can install a relay and hotwire it!?! as long as the lowest voltage with activate the relay. And as long as these "Walbro internal regulator" can keep up with the system.

mdwatts11

iTrader: (4)

Supercharger manufacturers sell boost a pump kits for vehicles with the FPCM. According to other members and their contact with the manufacturers say you can. Please keep us posted. If you have time, take pics of how the Hotwire kit installs with the FPCM. Good luck.

2FAST4U

Ok after a few more calls. I am told it will work, however the life and performance of the pump installed "as is" is questionable at best. Meaning wiring and FPCM are not as good as a hotwire or better a BAP.

He said a pump can only pull as much as it's given so less than 12V is low output and less pressure. 12V is rated output and BAP is 12V-22V so MAX output. (why 22V no idea but it says that)

So a BAP is just using the *trigger wire from the FPCM to tell the controllable output to pump wires to go or even increase the voltage based on user/boost/ect...

Concussion is with out a regulator in a featureless system. DO NOT over drive the pump as the internal regulator cant keep up. But full drive(12v) at all times is fine.

So hotwire diode isolated to the pump with a boost switch on the hotwire.
Would like a inline regulator right on top of the pump.

As I said if this doesn't work I keep the hotwire. Cut the feed line at engine install a return regulator and braided line back to tank. Then I can run the pump as hard as I like.

2FAST4U

*Update*
Any and all help would be great. PLEASE
I bought the hotwire. And a regulator with boost reference. So the plan is.
-factory fuel line is new return adapter to -6 to regulator
-braided -6 from regulator to adapter to rail
-braided -6 from regulator to tank
- then -6 90* into sending unit and to pump. (new hole drilled in unit)

mdwatts11

iTrader: (4)

Well in that case, you'll be deleting the FPCM correct?