I`m test if fuel pump is dirty and I wired it riverse for 10 sec.
After that I have huge missfire!!

I replace filter, think it was dirty, but still have missfire.

whats happend ... some ideas?

maby injector ...

 

You have probably broken the pump check fuel pressure

 

It won't damage the pump as the polarity has been reversed so it simply just runs in reverse, however when you done this with the filter connected it may have sucked the muck from it, thus the filter will now be empty as well, have you gone for a drive as sometimes it can take a while for the filter and things to prime so to speak as there will be no fuel in the system with the pump run in reverse!

Martin

 

I reconnected vacum several times to fuel regulator and hit injectors and missfire is gone!

I tried with reverse pump wiring becouse i think that fuel pump is weakened.
Car do not accelerate like it once, earlier...

 

Spinning the pump the wrong way, is very effective at blowing any crap out the pump, but back into the tank, as I needed to do this a few times for various reasons before replacing my tank, it does no damage, the anti drain back valves are not 100% effective, it wouldn't need a prime if they were.
tabetha

 

Is this right way to measure fuel pressure??

I have 30 psi measured on this way, i think that is like 2 bar...

Does someone know right way for this measuremant?





This guage is for wather pressure

Thanks

 

Your reg is upside down to normal!!
But yes so long as that is showing rail pressure, as it appears to be looking like a 8 injector fuel reg, that's correct, and low fuel pressure, so long as the gauge is not broken!!
tabetha

 

upside down? vacuum comes down and fuel return is up.

pressure regulator is Bosch 0280160202 (3 bar fuel pressure regulator with vacuum connection. 2 pcs pressure connection and one connection for return. Fuel connections 8 mm)


But If Im understand well I must connect guage between pressure regulator and fuel rail.

am I wrong?

PS. sapphire cosworth 4x4 green head

 

Nope the supply hose is on the bottom and the vaccum pipe at the top where it has the scribings/adjuster, thats how it should be at least on 2WD!

Martin

 

Your fuel reg is upside down, the actual weight of the fuel inside will be acting on the 2 diaphragms inside that seperate the fuel air(vac side), and pushing against the vac side.
It needs to be vac pipe at the top, along with adjuster screw, fuel feed in the side(as it is) and fuel return on the underside.
As your gauge is not going to have two fuel returns from it, the pipe where you connected the gauge must be another rail feed, it's not a 2wd(cossie) pressure reg and doesn't look to be a 4wd one either, the 2wd reg has two threaded holes on the underside either side of the return pipe that the bracket bolts to, and the other end of the bracket secures on the top corner rear bolt sticking through the plenum, with a 10mm nut.
That being the case and the location of the extra pipe it is in the fuel side so will exhibit precisely the same pressure as the rail before it, you can show this by squeazing the return hose briefly whereupon the gauge reading will go up, due to the "blockage" of returning fuel, it doesn't matter which side you measure it with this type of fuel reg, you could simply unplug and turn around so it is reversed if you wished, makes no difference, the pintle(valve) inside which controls the pressure is in the area immediately above the return pipe(inside), connected to the two thin diaphragms inside, so that the pressure changes with vac or boost as needed.
tabetha

 

Thanks

Does the standard fuel pressure regulator is 3 or 3.5 bar for 4x4 cossy?

 

The std pressure is 3 bar vac on, around 3.5-3.6 vac off and plugged.
tabetha

 

what you think, can the pump be the cause for low pressure?

 

have you checked your voltage at the pump too see if your getting full power at the pump ,its a good idea to rewire your pump

 

james I rewire my pump, 13,7v

hm maybe cossy need 3,5 bar fuel pressure regulator, not 3 bar like is mine...

 

I would certainly start by using the correct fuel regulator, even a well knackered pump would produce more than this at idle if it is driving ok, as there's next to no demand idling.
You are playing with fire using a pressure reg that almost certainly has different characteristics than those of the expected(by the chip writer) std fuel pressure reg, unless you've had it mapped on these, just get the correct pressure reg, it is also adjustable so can be set to the correct pressure.
tabetha

 

tabetha I buy car with this fuel pressure regulator, so I expected that is std

Do you know does std is 3 or 3.5 bar?

Thanks