Just gone out and had another play around with ECUscan.

With the engine already warmed up at idle the EGR valve is 4% open. By 1000rpm it's 20% open. Between 1250 and 2250 rpm it swings between 40% and 55% open and by 2500rpm it's 4% open again.

At a junction if I rev it loads I can pull away fine.
Anything less and it can be terrifying.

This is how my blanking plate looks like:



As you can see, it was more difficult to draw then to make it (0,6 mm sheet metal)

I put it on the underside of the EGR-valve

It cured the "hesitation" but I don't know if it will help you with the DPF problems.

Thanks Crombel.

I'll take care taking off the existing gasket and make one to your drawing.

I've got an offcut from a metal exhaust bandage that is about the correct thickness and fingers crossed it'll be good enough.

At this stage all I'm trying to do is to try and eliminate the various suspects - the dealer wanted over £500 to run tests to see what needed changing and I very much doubt they'd have come up with anything useful given their previous history with the car.

The DPF regenerates OK but throws the check engine and caps revs at 3k for a day or two while it builds up to it. I think this is an issue but might be different to the severe lack of low end power hopefully caused by the EGR. Or maybe even the dpf issue is caused by an EGR, or some other, fault and when I fix it the dpf issue may go away.

So far I had the dealer force regens, driven it until it does it itself, changed the air filter and unplugged the MAF and this made no difference.

The EGR seems the next logical thing to test / check.

Once again thank you.

Sorry to bother you again Crombel but can I just ask whether the 5 circles in the middle are holes?

Yes, five 6,5 mm holes.

Well, I've made and fitted the blanking plate - thanks again Crombel for the template.

I haven't punched any holes in it yet (so it's completely blanked off) but the car runs much faster and smoother than it did before. ECUscan reported error 0401 insufficient EGR detected but given that it's blanked that wasn't a surprise.

It's still showing the particle filter problem but I've got my fingers crossed that when I get the EGR cleaned and the proper gasket refitted I'll at least have one problem less to try and solve. There's a lack of power further up the range but I don't know how much of that is due to the DPS causing limp mode or whether there's something else again wrong. At least I've got bottom end power now so 1 out of 2 is better than none.

I'll keep an eye on it as it goes through it's next regen and see what happens.

As far as the EGR blanking is concerned I'm going to take it off again and punch so holes in it as per Crombel's design and see what happens then. Having it completely blanked off can't be good for anything.

Once again thanks to all of you for your help.

This Stilo thread has information on the EGR gaskets and their positioning in the 8V engine.
https://www.fiatforum.com/stilo/163320-egr-valve-remove-clean-modify.html

Post 21: Gasket part numbers.

Post 25: Gasket Images.

Post 40: Gasket positions within the EGR pipework.

I've now driven over 200 miles with the blanking plate fitted.

The car pulls fine in 5th and 6th as well as very sharply at junctions.

My average consumption over the 200 miles, a mix of city, town, motorway and rural driving was 41.8mpg which is as good as I've had with it, certainly in recent years and much better then I've had in recent months.

I'm going to make a couple more with variations of the bullet holes (3 and 5) and see what difference they make.

All I need to do then is find a decent local garage (Glasgow if anyone has a personal recommendation) to do the clean out and refurb of the EGR valve. I've had a read at the various guides and I just don't fancy my chances of taking it apart and then putting it back together.

All I can do then is cross my fingers and hope that this solves the DPF problem.

Lastly, thanks once again to all of you for your help, support and encouragement.:worship:

After doing just under 1000 miles with the blanking plate fitted I ordered a replacement EGR from emmissionscontrols.co.uk yesterday.

I had no problems with it blanked off - no noticeable increase in smoke anyway. Also, my fuel consumption improved by over 5mpg but that might be as much to do with the fact that I can now use 5th and 6th gears which must help.

The engine also went through at least 1 DPF regen cycle without reporting a fault, the initial problem I had with the car.

Got the valve next day and fitted it tonight.

It was a bit of a fiddle but not too difficult and I've got the old one to refurb.

Everything seems OK except for the odd lurch when I'm in second gear and go from 2000rpm to 2200 rpm. There doesn't seem to be any other problems I had it flying down the bypass in 4th, 5th and 6th with it revving from 2000rpm to 3600rpm and no lurch. It only happens sometimes and only in second. It doesn't happen when I'm changing gear. My only thought is that maybe I haven't got one of the bolts quite tight enough.

I'll drive it a bit tomorrow and see what happens.

Thanks again to everyone who helped.

BrianMcL said:

Everything seems OK except for the odd lurch when I'm in second gear and go from 2000rpm to 2200 rpm. There doesn't seem to be any other problems I had it flying down the bypass in 4th, 5th and 6th with it revving from 2000rpm to 3600rpm and no lurch. It only happens sometimes and only in second. It doesn't happen when I'm changing gear. My only thought is that maybe I haven't got one of the bolts quite tight enough.

I'll drive it a bit tomorrow and see what happens.

Thanks again to everyone who helped.

Click to expand...

Hi there, just wondering if you got to the bottom of the lurch between 2000rpm to 2200rpm? I had the exact same problem, of which the EGR was replaced hoping it would resolve. Unfortunately it has not... I don't get it all the time but I'd like to get to the root cause of it. Any ideas?

allarmsandlegs said:

Hi there, just wondering if you got to the bottom of the lurch between 2000rpm to 2200rpm? I had the exact same problem, of which the EGR was replaced hoping it would resolve. Unfortunately it has not... I don't get it all the time but I'd like to get to the root cause of it. Any ideas?

Click to expand...

Hi allarmsandlegs,
Not yet, however I can say with certainty that it doesn't do it when blanked off so it's most likely something to do with the EGR system / software.

I've got to say that having driven over 1000 miles with the new EGR valve fitted I don't notice it so much so I suppose it's something I'll have to live with.

Having said that I might try mucking around with different sized "bullet hole" gaskets in case I can determine a size that minimises the problem without triggering the insufficient reflow warning.

Zimples!

New full blanking plate. Drill one hole of 3 to 5mm diameter, centred?, and drive. If light comes on drill another, reset light/error and drive again. Repeat until no further errors.

Report back with number and diameter of holes so we can all follow on behind.

The Fiat plate I have has four holes of 8mm diameter, placed near the corners of the plate.

mine also lurches in 2nd only @ 2000-2200rpm yet i don't have a blanking plate, egr was cleaned by mechanic about 4000mls ago. I think it's just something that the car does, it doesn't mean that there is anything wrong with it

Thanks for the replies. I would agree that there is nothing seriously wrong with the car - certainly when mine was hooked up to the diagnostic checks there were no fault codes logged. It is just an unusual thing for a car to do... I guess it gives it character!

Yes, she is saying "don't tinker with the throttle BOOT ME HARD"

If the lurch is still there then she is lieing to you and you need to devise an alternative driving strategy

Update;
As I mentioned earlier I have put a bullet hole blanking plate on my 1.9 JTD 8V Croma.
The hesitation is almost completely gone, very rarely a hint of hesitation.
Fuel consumption has not risen but regenerations seem to take place at a much longer distance, from each 1000 km to each 1400 km.
I must admit that the few months in use are to short to make real conclusions but there is no negative effect until now.

The bullet plate has five 6,5 mm holes.

Sorry for my broken english.

Crombel said:

Update;
As I mentioned earlier I have put a bullet hole blanking plate on my 1.9 JTD 8V Croma.
The hesitation is almost completely gone, very rarely a hint of hesitation.
Fuel consumption has not risen but regenerations seem to take place at a much longer distance, from each 1000 km to each 1400 km.
I must admit that the few months in use are to short to make real conclusions but there is no negative effect until now.

The bullet plate has five 6,5 mm holes.

Sorry for my broken english.

Click to expand...

Do you have information on your bullet plate?

Part Number?

Number of holes at x mm diameter?

Part Number?

Number of holes at x mm diameter?

Click to expand...

Made it myself, drawing on previous page.
5 holes of 6,5 mm diameter

It is for an 8V engine.

Thanks guys for this thread, lots of information I will be able to refer to in the future if required.