Something strange with my duratec (megasquirt 2, stock injectors).

It was working perfectly fine. Stopped to adjust shocks and after that engine won't start. Fuel level was OK. After three tries, it catches but it was only firing 2 cylinders. As I was 3 block away, I return home and after inspection it looks like one injector is not working (I used an engine stethoscope).

I used a LED with the engine running to check power to the injector and it looks fine. Fuel filter was replaced 1000 miles ago.

Can this be a clogged injector? I'm going to check coil resistance today on that injector.

Any opinions much appreciated!

Thanks!

I would check for poor continuity first off, poor joint on the battery side of the injectors maybe, there should not be any voltage drop so check with a multimeter when it running.

If you think you have a faulty injector then swop it over for a cylinder that is firing if the fault moves to that one then its the injector. You wont be able to read the voltage pulse to the injector as its so short

[Edited on 3/11/14 by Dick]

If the injector is not working the exhaust manifold will start to heat up pretty quickly on that cylinder.
Sometimes they 'go to sleep' and can respond to a very light tap with a piece of wooden dowel or similar.
As you say though check the resistance in the injectors coil with a multimeter first and check the supply voltage. If you've used a noid light that is a good start.
The other thing might be to check the filter basket in the injector to see if that's ok.
I've used a stethoscope to check their working in the past as you can hear them operating.

Thanks for your replies!

I checked resistance, OK at 12 ohms. I swap the power to that injector for another and it's getting power.

So, I removed the fuel rail, put 12v in that injector and there is a very small spray of fuel coming out of it. Tested other injector and the spray is 10 times more

Althought the fault is identified now, I am a little concerned about the situation If this happend at 6000 rpm I could have broken a piston!

Thanks again!