On a 3.3ltr VK EFI motor after running it and then turning the engine off should the fuel rail remain pressurised or can the fuel run back thru the EFI fuel pump?
Mine has no pressure (checking the schrader valve at the front of the rail), once engine is switched off.
Don't know whether this is normal, or if the fuel regulator is U/S (trying to get my hands on a fuel pressure gauge).
The car runs fine.
According to the VK book I have, it should remain under pressure, cause they stress the fact that you MUST depressurise the fuel system before working on it.
Is this correct?
Cheers
EFI fuel pressure regulator
Started by
_whiteLC_
, Sep 19 2006 09:29 PM
5 replies to this topic
#2
_Herne_
_Herne_
-
- Guests
Posted 19 September 2006 - 09:42 PM
Not sure about 3.3 EFI but with the V8's the unspent fuel is returned to the tank via a return line so I am gussing once the engine is off there would be no pressure in the return line/rail? But am new to EFI technology and I could be wrong.
Herne
Herne
#3
TerrA LX
-
- Members
-
- 14,241 posts
Fulcrum Fixture
- Location:Sid 'n' knee
- Joined: 31-May 06
Posted 19 September 2006 - 10:32 PM
fuel pressure can bleed off due to a worn pump or defective reg.
try clamping the line just before the pump to determine which one is at fault.
you should not loose pressure.
try clamping the line just before the pump to determine which one is at fault.
you should not loose pressure.
#4
_whiteLC_
_whiteLC_
-
- Guests
Posted 20 September 2006 - 08:39 PM
OK, I've done some testing.
If I clamp off the return line hose at the same time as the engine is being switched off, there IS pressure remaining in the rail (still haven't got a gauge, but there is far amount of pressure).
If I don't clamp anything, when I switch the engine off the pressure drops off straight away to nothing.
Fuel pump is NEW and injectors were cleaned, flushed and a kitted before installed.
The fuel regulator was the one that came with the EFI setup when I bought it secondhand (condition used and unknown).
So I reckon its the fuel regulator......
Does that sound right before I fork out for a new one??
p.s. I have plans for a small supercharger in the future so would I be better to get some sort of EFI rising rate regulator?
Can I just use any sort of EFI fuel regulator thats the same rating?
If I clamp off the return line hose at the same time as the engine is being switched off, there IS pressure remaining in the rail (still haven't got a gauge, but there is far amount of pressure).
If I don't clamp anything, when I switch the engine off the pressure drops off straight away to nothing.
Fuel pump is NEW and injectors were cleaned, flushed and a kitted before installed.
The fuel regulator was the one that came with the EFI setup when I bought it secondhand (condition used and unknown).
So I reckon its the fuel regulator......
Does that sound right before I fork out for a new one??
p.s. I have plans for a small supercharger in the future so would I be better to get some sort of EFI rising rate regulator?
Can I just use any sort of EFI fuel regulator thats the same rating?
#5
TerrA LX
-
- Members
-
- 14,241 posts
Fulcrum Fixture
- Location:Sid 'n' knee
- Joined: 31-May 06
Posted 20 September 2006 - 09:35 PM
not sure about your supercharged application but if you arnt loosing fuel thru the pump then i say the reg is stuffed.
a new reg may improve idle and even performance if this is the case.
a new reg may improve idle and even performance if this is the case.
#6
_jap-xu1_
_jap-xu1_
-
- Guests
Posted 02 October 2006 - 10:00 PM
if it will not hold pressure you eithe have a fuel leak(unlikely)
have a regulator that is allowing fuel to seep past it(also unlikely)
or you do not have a 1 way valve after the high pressure pump.
us efi guys always use a speedflow check valve to overcome the cold start problems associated with lack of pressure on startup
have a regulator that is allowing fuel to seep past it(also unlikely)
or you do not have a 1 way valve after the high pressure pump.
us efi guys always use a speedflow check valve to overcome the cold start problems associated with lack of pressure on startup
1 user(s) are reading this topic
0 members, 1 guests, 0 anonymous users
