Fuel Rail & Pump Question

rossnunn · Post by **rossnunn** » 09 Mar 2006, 13:38

On my old single point injection engine, the fuel return pipe was connected to the injector housing.
This Multipoint used a single entry fuel rail with no return, but in the breakers I found they did one that had a return pipe, so I pulled that & put it in mine.
Now this fuel rail has, what I believe to be, a vacuume operated valve that opens the return part of the rail.
On the car I took it off it had a valve on the side of the inlet manifold for it, but mine doesn't have this valve, (you can see the blank in this pic) from what I can see mine uses one of these;

Will it be ok to put it inline with that? If so which side of the valve/sensor shouold I put it?

This is a pic of the end of the fuel rail;

-------------------------------------------------------------------------------------

Did they use a lower pressure fuel pump on cars which did not have a return pipe for the fuel?
I ask these questions as my ZX still has this cough which I did put down to the fact the lambor wasn't connected, now it is things have not improved. My next thought wass that if they used a lower pressure fuel pump on non-return rails this could be whats causing my problems as the car is dumping too much fuel?

Cheers

Ro

wheeler · Post by **wheeler** » 09 Mar 2006, 18:43

the thing circled in green is the charcoal canister electrovalve,its only used for alowing fuel vapour back into the inlet manifold.
the thing on the end of the fuel rail is the fuel pressure regulator.

rossnunn · Post by **rossnunn** » 09 Mar 2006, 20:07

aaah good stuff, so would the FPR go inline with the elecrovalve?

wheeler · Post by **wheeler** » 09 Mar 2006, 22:44

rossnunn wrote:aaah good stuff, so would the FPR go inline with the elecrovalve?

No,they are not even part of the same system,the electrovalve alows fuel VAPOUR to be re introduced into the inlet manifold rather than venting it to the atmosphere,it is part of the emissions system.
On models without a fuel return on the rail,the FPR is usually located on the fuel pump/sender assembly.

rossnunn · Post by **rossnunn** » 09 Mar 2006, 23:05

bugger, right ok.
So I'll need either a different inlet manifold or a fuel pump assembly

rossnunn · Post by **rossnunn** » 14 Mar 2006, 23:33

right I started the car today (after the snow had finished

) and sucked on the pipe coming off the fuel pressure regulator for all my might then put my tounge over the end, the result? well not alot really, infact it seemed to be slightly worse

rossnunn · Post by **rossnunn** » 16 Mar 2006, 17:36

Ok went up the scrappie today & had a look round a saxo, sure enough I found the FPR as suggested on the tank.
I very nearly took it off but didn't because I didn't know where the other pipework went.
Does anyone know?

Here is the bit I was refering to in my ealier posts (circled in yellow)

RED ARROW: FPR Connects to the bottom
GREEN ARROW: Goes off to the charcoal canister electrovalve
BLUE ARROW: Fuel Connectors
PINK ARROW: Throttle Cable