Help please

2003 Yamaha 5PW engine turns over but the injectors do not let any petrol out had them off and cleaned them checked injectors are pulsing also got a spark from plugs, the fuel pump is pumping fuel in and out of fuel rail.

I have had the injectors out twice now and am sure they are clean cleaned them in injector cleaner soaked them for a few hours, blew them through with air line at the nozzle end and on all four injectors saw injector fluid blow out the other end.

The fuel inlet hose is on the fuel rail above the cold start assembly (if that's what it's called) and the return is from the pressure regulator on the right above oil filler cap.

Iv'e had the inlet hose off and the fuel pump running there is fuel flowing, iv'e had the inlet hose on and the return hose off and fuel exits the pressure regulator.

I know injectors are clean set up a test rig to pump injector fluid through whilst pulsing injectors.
Fuel pump is a fuel injection Bosch pump no 0580464070 spec Ltr min @ 3 BAR 2.25, lockout (bar) 7.2, when ignition is on can here pump working but it does not shut off also when i disconnect the inlet on the fuel rail there is no pressure, according to the haynes manual for my engine the fuel injector operating pressure is 41 PSI (2.84) BAR.

Just fitted an inline pressure gauge to check if fuel pump is pressurising system and as soon as ignition is on pump starts pressure goes up to 3 bar as soon as i turn off the ignition pressure drops to 1.2 bar in about 2 minutes and down to zero in four minutes.

If the tip over sensor was thinking the engine is on it's side would this cause the problem no fuel out of injectors, i have glued magnet inside into the position were it should think bike is upright ????.

Dave.

I had this exact problem myself, are the injector solenoids actually actuating? I had this with my r1, because it had been sat for a while the solenoids inside the injectors had partially seized / sticking & the pulsing from the ecu was not powerful enough to get them to fire, I removed & made up some fly leads to give them a direct feed from a battery which I pulsed & they freed off, I heard the solenoids start clicking, I did this to each 1 & then refitted them & my engine fired up as soon as I hit button, just a thought mate

Tip over sensor will cause this, maybe see if you can borrow another to try? i stuck mine up and it didn't work on the first attemp i think i must have stuck it slightly out of place

+1 on confirming the injectors are actually opening...any chance you can unbolt the fuel rail and leave the injecotrs on...then crank (I don't know your engine); that'll confirm 100% if fuel is getting into the cylinders.

Any other changes to the engine? Anything that could throw off the timing?? (Spark, fuel, timing...not much else to check).

good luck!

Hi Dave, do you have the original clocks? if so there is a really good diagnostics feature where you can run the injectors to see if they are clicking along with checking all the other major components with the use of a haynes. Will also be able to tell you the tip over reading i believe to which you can adjust it if it is a problem. I originally only had one clicking loud. like you had done i soaked mine in petrol and injector cleaner and they slowly came back to life.

[Edited on 13/6/11 by bassett]

Tip over sensor i stuck it down in wrong position even though reading of multimeter said that engine was in the upright position.

So tonights the night will see if i can get her started.

Thanks for your help guys.

Dave