Injector Waveform: Ford Mondeo MK3 1.8 Duratec HE 2006

Ben0815 · Post by **Ben0815** » Wed Feb 09, 2022 3:49 pm

Hello everybody,

I bought a PicoScope 2204A in order to find the cause for a rough idling engine with slightly pulsating rpm on a Ford Mondeo MK3 1.8 Duratec HE 2006. No DTCs, no misfire counter.

When I came across to measure the injectors 1-4 with the PicoScope, I came across these waveforms (s. attachments, 2 CHs = 2 Cyls), which show single and suddenly appearing double injector signals. These inconsistent signals appear to be in sync with the audible and perceptible misfires.

Can somebody evaluate these waveforms/signals?

Thank you,
Ben

liviu2004 · Post by **liviu2004** » Thu Feb 10, 2022 9:19 pm

I would scope cam and crank at this point, as something makes the ecu believe it has to fire those injectors again.

Ben0815 · Post by **Ben0815** » Fri Feb 11, 2022 6:49 am

Thanks for the reply. Here are the crank-/camshaft waveforms + crankshaft and injector 1:

liviu2004 · Post by **liviu2004** » Mon Feb 14, 2022 7:29 pm

I don’t really see something wrong in the waveforms, so it must be ecu strategy for post injection triggering, why, I’m not sure, maybe dpf cleaning or raising its temperature faster?

muttnjeff · Post by **muttnjeff** » Tue Feb 15, 2022 12:47 am

cant say I know anything about the particular model in question I can tell you that in heavy trucks there is a strategy called low NOx idle, in the past it caused many issues with techs trying to diagnose an issue that was not an issue but rather a strategy by the OE for NOx reduction during low coolant temps & low idle speeds.

It would give the idea of a no fault misfire/rough idle...

Dcunning35 · Post by **Dcunning35** » Fri Mar 11, 2022 6:45 am

The egr valve on these causes a symptom like you describe ,it's a small water cooled item bolted directly to the cylinder head above the transmission. I would suggest blanking it just to see if it's having any influence.
Danny

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