FMU Boost source question

[l6u9k6e9]

Hey, im getting ready to install my fuel pump, and fmu. Ive read the write up on how to do it but im not sure where to tap for the boost source for the fmu?.


"i used the brake booster line to feed my FMU and my boost gauge"


What line is this where is it?


also for the other lines....

"use some fuel injector hose and connect the stock fpr return line to the side nipple of the fmu."
"then connect some fuel line from the bottom nipple to the fuel pump's return line"

Do i have to tee off of these lines? or do i just hook them up directly?

 

[selmerguy]

as for the boost source you hook it up to the intake mani whever you want. the brake booster is the big hose in the mani.

and for the fuel lines the fmu acts as a tee. you hook them directly in to the return line.

 

[VelocitàPaola]

I know... I've been posting this everywhere, but a picture's worth a thousand words.

You must be logged in to view this image or video.

 

[l6u9k6e9]

sorry, i just really dont want to fak this up. So all i have to do is cut the fpr return line and hook up the side closest to the engine to the side nipple, and the line going to the tank to the bottom? correct?,,,(sorry for being slow)

Also when you say anywhere off the mani? do i have to run a hose all the way to the front or can i just tee off of a line in the back? <-- is this the brake booster line? if so should i just tee into it?

 

[VelocitàPaola]

sorry, i just really dont want to fak this up. So all i have to do is cut the fpr return line and hook up the side closest to the engine to the side nipple, and the line going to the tank to the bottom? correct?,,,(sorry for being slow)

Correct.

Also when you say anywhere off the mani? do i have to run a hose all the way to the front or can i just tee off of a line in the back? <-- is this the brake booster line? if so should i just tee into it?

You'll tee any vacuum line you want coming from the intake manifold (except the one from the throttle body). You can use the brake booster line, but it doesn't go very far back, so you will need to run a line to wherever you choose to mount the FMU.

 

[selmerguy]

yes you will have to run a line all the way to the motor. have fun

 

[l6u9k6e9]

So it would be easiest to put the fmu in the engine bay? Now i just have to find the fpr return line. Here is a picture, anyone? Which one will i be hooking up the fmu 2? From the looks of the diagram it looks like #1, is this correct?

 

[l6u9k6e9]

Sob i go to install the damn fmu, and i only have 1 line going off of the fuel rail!!!

looks like this..... wwhat do i do?

 

[selmerguy]

dude......... you have a 99 you should install the fmu by the tank. your fpr and return line are there.

 

[l6u9k6e9]

How do i know which hose to tap into back there? what would happen if i tapped into i guess its the feed line, would it have the same effect?


There are so many f****ng hoses back there and so little room! holy shit this is frusturating!

Anyone?

 

[VelocitàPaola]

How do i know which hose to tap into back there? what would happen if i tapped into i guess its the feed line, would it have the same effect?


There are so many f****ng hoses back there and so little room! holy shit this is frusturating!

Anyone?

It would not have the same effect. The FMU works by restricting fuel flow out of the rail, thereby increasing pressure within the rail, forcing more fuel out of the injectors.

If you really want reassurance, pull your back seat (comes out by pulling on two tabs), open the gas tank access cover on the passenger's side, then open the gas tank itself. You'll see two hoses coming from the tank, and once you open it, you'll notice one comes from the pump (the feed) and one just ends (the return). Trace that line to where you need to put the FMU.

You shouldn't need to do all that... but if you want the reassurance, by all means...

Check this page too. I found it a little confusing and disorganized, but it might help.

http://www.2gnt.com/nuke/modules.php?name=Sections&op=viewarticle&artid=59

 

[VelocitàPaola]

Also, don't follow that link too closely.

In fact, don't follow it at all - it's for an SFMU install, in which case you would remove your stock FPR. If you're only running an FMU, you need to keep the stock FPR. If anything, only use that link for help in locating the return line.

 

[l6u9k6e9]

got it,, thanks!!! that sfmu post really helped! once i took off the fuel pump cover and removed that hose it was cake, i just pulled it out the bottom.

one more quick question, will my fuel system function normally if i do not have the boost source hooked up yet? I just have to run to home depo and get a tee.

I plan on getting boost of the manifold from here....

 

[selmerguy]

got it,, thanks!!! that sfmu post really helped! once i took off the fuel pump cover and removed that hose it was cake, i just pulled it out the bottom.

one more quick question, will my fuel system function normally if i do not have the boost source hooked up yet? I just have to run to home depo and get a tee.

I plan on getting boost of the manifold from here....

i think so. but am not sure. you will know real fast if you have to run the boost source.(black smoke and bad idle) i don't know if the vacuum keeps the valve open and then boost shuts it or if it is open till boost beginss to shut it. i will go un hook my vac line and tell you.

 

[selmerguy]

yes it still runs fine

 

[DSMcrazy3]

You should be fine for one trip..I would assume you will be running alittle bit rich due to the bigger pump being in(granted it's installed..) but for one trip I think you're fine.