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.

Dave

I think this is a common problem with these I had it and know 3/4 other people with the same. My solution was to take the injectors off, take the rubbers off (learnt this after the first go when they disintegrated) and soak the injectors in injector cleaner/carb cleaner or similar product I did it over night but other have done it for an hour and had the desired result

Are your fuel feed and returns on the correct ends of the fuel rail? Return from the end with the regulator?

You wouldn't be the first.

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 regulator.

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 regulator.

Dave

It could be the pump not making presure (it might still have flow). Usually it'd fire and stop if that was the case though. If you switch on and wait for the pump to build presure and stop, switch off, wait 20/30 seconds and then pull the feed pipe off the rail, does it have residual presure? You should get a bit of a spurt - BE CAREFULL !

You are using a high presure Fi pump aren't you? Again you wouldn't be the first.

I had this exact problem with my 5pw r1 a few years ago. Turned out to be the fuel pump. Although it could be heard pumping it wasn't putting anywhere near enough pressure out of the pump. Quite a common problem it turns out. If I was you the first thing I would do is just put a pressure gauge on the fuel line and see what your getting. Blocked injectors are possible but the possibility of all 4 at the same time is very slim.

Just spent all morning on fuel side of problem 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.

Sounds like something is not right to me comments please.

Dave

What i have done since above post.

Just fitted an inline pressure gauge to check if fuel pump is pressurising system and as soon as pump starts pressure goes up to 3 bar as soon as i turn off the ignition goes down to 1.2 bar.


Dave

In that case the fault must lay with the fuel pressure regulator on the end of the fuel rail. It's the only thing left that would stop the injectors spraying. The tip over switch stops voltage to the fuel rail but sure you said you have voltage there???

Thanks for help guys.

Found problem it was the tip over sensor my fault stuck it down in wrong position, will try tonight to fire up the engine.

Thanks again will post tomorrow if engine starts.

Dave