M30 FPR pipe connection

Post Fri May 30, 2008 1:00 am

Where does the pipe from the FPR on an M30 go to? I'm guessing it's to one of the connections on the bottom of the inlet manifold, but mine came connected to nothing...

So just to be sure - there are 2 connections on the bottom of the inlet mani - where should the other one go?

Ta

Post Fri May 30, 2008 2:13 pm

front hose on the manifold, to the FPR
rear hose on the manifold to a stub that comes off the rocker cover to inlet breather pipe (between TB and AFM)

Post Fri May 30, 2008 2:26 pm

That sounds about what I was expecting, thanks

Excuse my ignorance, but what does it actually do?

Post Fri May 30, 2008 2:29 pm

now you mention it... it's a bit odd! it effectively bypasses the TB. i assume it's to suck up crankcase fumes while at zero throttle?

Post Fri May 30, 2008 2:33 pm

FPR? Fuel Pressue Regulator?

Post Fri May 30, 2008 7:35 pm

Post Sun Jun 01, 2008 12:27 am

So just to make sure the front stub is for the fuel pipe, and the back one for the return?

Think i've got these the wrong way round then as i tried to start today with no joy, turns over but didn't fire up. Would this have damaged anything if i've put them wrong way round and tried to start it?

Cheers for your help,

Shaun.

Post Sun Jun 01, 2008 7:41 pm

It shouldn't harm anything, but be careful when you take the hoses back off.

One of them builds up pressure so wrap them with a rag or something while you remove them or fuel will spray out, probably in your face!

Post Mon Jun 02, 2008 7:47 pm

ahh kool, well rather that than something on the ignition going wrong,

Do you know if the one closet the bulkhead is the fuel intake? As the M30 is turning over but not firing, any suggestions? all wired up apart from the extra connectors by the ECU have no where i can find to plug them in to, have livened up the wires that should be live...

Please help, i know wrong thread but if you can help i would really appreciate it,

Cheers,
Shaun.

Post Mon Jun 02, 2008 8:45 pm

The one that doesn't go to the FPR is the intake! Easy enough to trace, but I can't remember which that is, off the top of my head.

gareth wrote:now you mention it... it's a bit odd! it effectively bypasses the TB. i assume it's to suck up crankcase fumes while at zero throttle?

Sounds plausible... So how does a Fuel Pressure Regulator work, & why does that need a vac hose connection too?!

Post Tue Jun 03, 2008 12:31 am

Ziggy wrote:So how does a Fuel Pressure Regulator work, & why does that need a vac hose connection too?!

the load on the engine results in a vacuum in the inlet manifold. this is sensed on a diaphragm within the FPR (via the hose) which raises the fuel pressure when the throttle/load is increased. it does this by restricting the outlet from the fuel rail (return to the tank)