We bought our Mk2.5 in 2014 with 24K on the clock and it's now just passed 55K. Ever since we've had it I've noticed a tendency for it to become a bit 'snatchy' within the first few minutes of driving from cold when on light throttle on the local roads. This disappears after a few more minutes, presumably after it's warmed up a bit more. I've never bothered about it but SWMBO has complained of it stalling when she had to stop for some oncoming traffic a few hundred yards from home. I used it today and it didn't seem any worse than usual. I have checked for codes with Forscan and, as expected, there aren't any.

I seem to recall reading another thread on here recently about swirl flaps possibly being the cause of a similar problem on a 2.0 Litre of around the same vintage so I was wondering if the 1.8 has a similar set-up and whether that could be the culprit.

I've never used Forscan to record live data but could anyone suggest what parameters I should look at if I try it?

Yes, the 1.8 & 2.0 Duratec HE use the same inlet manifold.

I have read that the swirl flaps on the latter engines, which yours is one, had been redesigned to avoid the failure.My brother did have the actuating vacuum switch fail but this threw up the engine light and dtcs.

just out of intrest, are you running on e5 or e10 fuel? Probably not your issue though.

Since the switch to E10 I've been running it on premium E5. Apart from this brief glitch it performs flawlessly. It seems to happen after a couple of minutes of running, lasts for another 2 or 3 minutes and then disappears. And it's only with the engine very lightly loaded, feathering the throttle. If I'm able to drive away at larger throttle openings it doesn't happen.

@TomsFocusany thoughts about what PIDs to monitor to get a possible handle on it?

2 hours ago, mjt said:

Since the switch to E10 I've been running it on premium E5. Apart from this brief glitch it performs flawlessly. It seems to happen after a couple of minutes of running, lasts for another 2 or 3 minutes and then disappears. And it's only with the engine very lightly loaded, feathering the throttle. If I'm able to drive away at larger throttle openings it doesn't happen.

@TomsFocusany thoughts about what PIDs to monitor to get a possible handle on it?

Not really, I'm afraid.

It may even be a mapping glitch, that only occurs within a small coolant temperature band for example.

You could watch the coolant temp to see if it happens at the same temp each time.  Could check lambda readings.  Could check EGR opening.  Could watch fuel trims, although that's more for a vac leak.  

Difficult to know where to begin with such an intermittent fault and no codes.

Ok. Thanks. I've always assumed it was a mapping glitch related to temperature, perhaps leaning off the mixture a bit early, and as I said it's never been an issue for me but I'm now trying to convince my wife that there's nothing major wrong with it . It's rather piqued my interest so I'd quite like to find a reason for it. Probably shows I've got too much time on my hands .