Just found another thread with some similar sounding issues which were again attributed to the EGR.

The "cough" they describe is particularly familiar.

https://www.fiatforum.com/croma-ii/178521-hesitation-stumble-fix-multijets.html

I think it's time to insist the dealer checks the EGR out. If there's nothing wrong with it, then I'll pay the labour charge, but if there is, then they can get it sorted.

I've just remembered something.

Years ago, I had a mondeo ST220 that had a flat spot/blip at the exact same part of the rev range every time. It was 2nd hand, so I decided to get a full service done with all filters, spark plugs, leads etc. Cost me a sizeable amount as I got all the genuine parts through ford.

When I got it back, the problem was still there. I just learned to live with it, and did so for months.

As it's a performance car, I'd been running it on 97ron from the day I got it. One day, the fuel station I always use had ran out of 97ron, so I put a tank of 95ron in. The blip instantly disappeared.

From that day on, I ran it on 95ron fuel, and the problem never reoccurred.

Maybe I'll try a few different fuels over the next few weeks. I currently run it on Esso fuel from the local Tesco station.

Just back from the 2nd local dealer now.

Basically, as it's already been looked at by another dealer and deemed to be in perfect working order, they won't spend any time on it until we try another car to see if the issues are just a characteristic of the vehicle.

My feeling is that if it was a "characteristic", then it'd happen all the time rather than intermittently. They tell me that's not the case, but surely an intermittent fault is more of an anomaly than a characteristic.

They were able to feel the hiccup at 1500rpm, but I was unable to demonstrate the morning running issue as it only lasts a few minutes on a morning.

Unfortunately, the first dealer have been trying to source another car for me to try since February, so I don't see that happening any time soon.

About 4 weeks ago, I decided to disconnect the MAF sensor on my car. I hadn't considered doing this in the past, as the dealer has already checked the MAF over, and on all the road tests, it was considered to be reading values in the correct range.

Long story short, disconnecting it transformed the car. I ran it for 3 weeks, and not once did I experience any stuttering in the mornings.

Not only that, but the car feels a whole lot different. It seems more willing to run at lower revs, and just feels a lot smoother when running around town.

The little hiccup at 1500rpm is still there, but I've found that I can reduce that to a barely noticeable level by using premium diesel.

I've also experienced what I believe to be a significant improvement in fuel economy. No matter how I've driven in the past, I have been unable to get more that 44mpg, and generally average 42.5-43. Over the last 800 miles with the MAF disconnected, I've averaged 48mpg. This is in no way connected to the premium diesel, as I've ran a few tanks through in the past and actually saw a decrease in fuel economy.

With all of this information in hand, I booked the car back into the dealers. I reconnected the MAF before I dropped it off, and as soon as it was connected again, the problems came back.

I've just spoke to the dealer, and they've fitted a new MAF. Hopefully this will fix the problem, but only time will tell. I'm picking it up tomorrow and will keep you all posted.

On a different subject, I'm happy that the dealers have also ordered me a part in to fix my noisy rear brakes under warranty. They were starting to get ridiculously loud!

Edit: My apologies......I've just re-read through this after posting and realised that it was in no way "long story short".

Fingers crossed!!!!!

Well...unfortunately, the new MAF hasn't fixed the problem. I am however still getting really good MPG, so I'm not sure what's happening there. Maybe the MAF was faulty too!

Fiat called me yesterday to see if everything was ok now. I hadn't had enough chance to test at that time, but whilst they were on the phone, they mentioned something which I find a little strange.

Apparently, the new MAF that was fitted is a Euro 5 version. I said that was a little concerning as it's a Euro 6 engine. They told me that a lot of customers have been having issues with low power from the Euro 6 engines as they're so constrained due to their focus on emissions, and that fitting a MAF from a Euro 5 engine would give it more power.

I said that I don't see how that would work, as it's only a sensor, and a properly working Euro 5 MAF should surely read the same airflow as a properly working Euro 6 MAF...and unless the ECU was remapped to interpret the airflow readings differently, I doubt it'd make any difference.

His answer was that any technical questions would need to be directed to the dealer, as he was just repeating what he'd been told.

I feel like they're just making things up now. I may be completely wrong, but I can't see how it'd make a difference. I'm also surprised that Fiat have condoned fitting a part from a different engine.