focus 2005 petrol injector wavform

hi guys
I have a ford focus 2000cc with a duratec engine which is lumpy at idle I replaced the plugs and coil packs before starting diagnostics, the car had a lpg retrofit kit fitted which during investigation was removed , the engine is showing no fault codes so out came the scope.
I have checked the crank and cam shaft sensors (trace attached below) and they seem to be fine.

But the petrol injectors are pulsing after the main pulse which is timed correctly intermittently about 30% of the time on all four cylinders and can be seen in the scope trace .


as everything else seems ok any ideas ? is this an ecu fault? would you expect a trace like this from a petrol injector?

thanks in advance

nick

Secondary ign captures with exh pulses so we can work out the misfire type/cylinders(s) at fault ?

It will be difficult to view/manipulate your captures as this is a forum related to the Picoscope.

Fuel trims ?

Looks possible the injector pulse has gone asynchronous.

Nick,
Not sure if this will help you. here is a 2003 Focus 2.0L Zetec. Hard to tell but your cam transition seems to be at 70 deg ATDC. Still in PIP high(bearly) window BUT That's probably why its not coding??? The file I have is 50 deg. ATDC. Like I said hard to tell. Hope this helps you.

Karl

I have a ford focus 2000cc with a duratec engine which is lumpy at idle

I could be wrong but that second image seems odd. To me that looks like 1400RPM ???? Have I misread that?

If that is the case you must be using the throttle. That injection may not be a fault.

Really need more captures as Robski mentioned to ID cyl.

the car had a lpg retrofit kit fitted

Depending on vehicle/engine and miles valves and seats would be at the back of my mind for a lumpy idle.


HTH
FF