General New Croma - acceleration problem

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General New Croma - acceleration problem

Just been reading with interest the lack of acceleration thread. My last car before the Croma was a Marea Weekender JTD105. This had a problem 3 times with lack of acceleration. I took it 1st time to a locally recommended auto electrical chap who hadn`t seen under the bonnet of a diesel Marea before. When I described what the problem was he connected his diagnostic screen up to the plug on the car and it came up with a fault number which said it was the ERG valve. However he was not convinced as he had had some Vauxhalls and Renault diesels which had come up with a similar result but even changing the ERG had not cleared the original problem. He then took off the air volume sensor between the airfilter and the turbo intake it was only an electrical resistor with coloured bands on with the wires either side of it showing distinct corrosion. Changing this solved the problem. I had the problem twice more always in the spring after winter weather had done its dampest! This problem must be well known to Fiat as the part is now an exchange part.
One good hint is to change your air filter in the autumn this has meant I had the last two winters without the sensor probs and my son who now has the car has had no problems after the last winter. I hope this is of help to anyone who experiences lack of power . also you can get a lot of air filters for the price of one air volume sensor !!
PS I have been told that the ERG dumps the turbo pressure to the manifold to protect the turbo seals during decelleration , I think it would be foolish to blank it off .
 
I have had this problem myself - twice! The first time was a problem that grew incrementally over a period of time. This turned out to be the EGR valve. The second time was rather sudden - I pressed the "go faster" pedal and... it didn't. This time it was the gasket on the inlet manifold. Bother! Got both fixed under warranty at the local Fiat garage.
 
I'm joining the Croma owner's gang tomorrow (picking up my 1.9 prestigio from a dealer).

Just phoned the dealer to check that everything's ready for tomorrow, and he says they've taken it to the local Fiat dealer as a light was lit on the dashboard. It's having ... a new EGR valve. Will still be ready for tomorrow though.

So I'm glad I've got this issue dealt with before I even get it - I was a bit worried having read this thread. I'm very impressed with the dealer though - it's still under manuf warranty, but it doesn't apply as I haven't yet transferred it to my name, so they are paying the Fiat dealer to fix it (he said about £200).

So hopefully I won't have any more EGR issues if it now has the new improved version.

I wonder if this is why the previous owner got rid of it.
 
Turbo waste gate deals with overboost surely?

Check the drive for rattles and knocks over bumps, and check the lifetime on the brakes - they've expencive things to replace.

Cheers, will do, although wouldn't the odd knock or rattle be expected with the 18" wheels? The one I have already test-driven seemed a bit harsh (but acceptable).

It had new brake pads with a service, not sure about disks though. Are the brakes that expensive if you hunt out Vectra or Signum equivalents?

Sorry, gone OT for the thread. Thanks for the buyers advice though.
 
[ame]http://en.wikipedia.org/wiki/Exhaust_gas_recirculation[/ame]

Not sure if it worsens economy or improves it from that, but I think the main reason is to stop the bunnies choking on Nitrogen Oxide gas.
 
Hmmm. The part is on back-order, and can't be replaced for a week or two. Is the car OK to drive with a faulty EGR valve?
 
I dont know whether this will help, but my volvo was doing this and slowly got worse to the point where it nearly stalled if you tried to move forward on the clutch, and acceleration from 800rpm to 1800rpm was weak.

I checked the airfilter, and it was absolutely filthy with gunk so I literally took it out, wafted it around and tried to get all the bits out. Placed it back in the opposite way, and suddenly the car is very rapid and pulls low down in any gear. The car's needed a couple of days to "re-adjust", but there was almost an instant difference is performance.

People were telling me it was likely EGR or DPF related.
 
You didn't put an air filter back in with the original dirty air side to the clean side did you? You may as well have poured sand into the oil filler cap.

This is not filter related, and the EGR can be confirmed by either removing and having the part cleaned until the cylinder closes again.. or having the gasket replaced with a solid blanking gasket until a new part can be bought/original cleaned.

Doofer - the car will be fine to drive with stuck EGR valve - but of course it will be low on power in the low revs.
 
And following up on the discussions regarding disconnecting the valve or blanking it off, I think I can confirm (from the workshop manual) that blocking off will eventually lead to the engine fault light coming on. This is because the engine management monitors how much gas is recirculated. See From the Manual below.

If after fitting the new improved EGR valves that Fiat/Alfa have introduced problems still persist then maybe the next sneaky trick is to connect the EGR inlet to the air intake system (post air filter but pre MAF). This should allow the system to think it is actually acting normally and also stop all those sooty deposit being drawn back into the system.

Having seen some of the pictures of people's bunged up EGR valves I wonder what the poor intake manifold looks like. Of course there will be a 85% dilution of exhaust gas by fresh air intake.

Nick /////
From the Manual:

This system makes it possible to send some (5 - 15%) of the exhaust gases to the intake in certain operating conditions.

This lowers the peak temperature in the combustion chamber restricting the formation of nitrogen oxides (NOx).

The E.G.R. solenoid valve (1) operated by the injection control unit (2) carries out the task of reintroducing some of the exhaust gases taken from the exhaust manifold (4) back into the engine intake.

A heat exchanger (3) makes it possible to partly cool the exhaust gases increasing the volumetric output of the engine.

OPERATION
At coolant temperatures of > 20°C with the engine speed between 800 and 3000 rpm, the injection control unit operates the E.G.R. solenoid valve with a square wave signal.

The variation in this signal allows the E.G.R. coil to move a shutter, thereby regulating the flow of exhaust gases from the exhaust manifold to the intake manifold; there are two results:

less air is introduced;

the combustion temperature is reduced (on account of the presence of inert gases) resulting in a decrease in the formation of NOx (nitrogen oxides).

The injection control unit is constantly informed of the quantity of gas recirculated through the information coming from the flow meter: in effect, if there is an intake of a certain quantity of air (Qam) for a given engine speed and the value sent by the flow meter (Qar) is lower, then the difference (Qgr) is the value for the quantity of gas recirculated

Qam - Qar = Qgr

Qam - Theoretical quantity of air memorized

Qar - Actual quantity of air

Qgr - Quantity of recirculated gas

The atmospheric pressure signal is used for the operation of the E.G.R. solenoid valve to recognize the condition of driving at altitude in order to reduce the quantity of gas recirculated and to prevent engine fumes.
 
Doofer - the car will be fine to drive with stuck EGR valve - but of course it will be low on power in the low revs.

Cheers for that. Got the car now, have driven a few hundred miles and think it's great even with the duff valve. Now letting it rest until it's fixed.

What a gorgeous car. Spent today on the M1 looking at people driving base model Vectras that cost about the same. Pity those poor uneducated souls.
 
You didn't put an air filter back in with the original dirty air side to the clean side did you? You may as well have poured sand into the oil filler cap.

This is not filter related, and the EGR can be confirmed by either removing and having the part cleaned until the cylinder closes again.. or having the gasket replaced with a solid blanking gasket until a new part can be bought/original cleaned.

Doofer - the car will be fine to drive with stuck EGR valve - but of course it will be low on power in the low revs.

No, I cleaned then rotated the filter (as you'd turn a steering wheel) and put in back in the right way up, its now just sucking through a much cleaner part which corresponds to the position of the air intake pipe, this is whilst I find a new filter.

As I say, the car was hardly accelerating properly prior to that. Now it pulls very urgently through all gears. Just my two cents.
 
No, I cleaned then rotated the filter (as you'd turn a steering wheel) and put in back in the right way up, its now just sucking through a much cleaner part which corresponds to the position of the air intake pipe, this is whilst I find a new filter.

As I say, the car was hardly accelerating properly prior to that. Now it pulls very urgently through all gears. Just my two cents.

Aha - that makes more sense. I must admit, I had the same "eeek" thought when I read your original description. It's probably a good way of getting a bit more life out of a filter.

I used to have a K&N air filter on my old SEAT, so got used to regularly playing with it - these are made out of cotton instead of paper, and rely on sticky oil to catch the muck, rather than just obstruction as paper filters do. You have to wash and re-oil them every so often. They (theoretically) allow the air to flow easier than a paper one, although some understandably worry about the oil vapour possibly sticking to the MAF sensor and god knows what else on the way in. Never had any problems myself though, and it did seem to make the engine spin up quicker - more of a "vrum" than a "vroooom", i.e. it went from slow revs to high revs much quicker. Just wondering whether to give one a try on the Croma.
 
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Hi everyone.

I seem to have fallen fowl of the no accleration problem too.
Initially i thought it was down to me never having a diesel car before and i wasnt applying enough throttle to move off.

But recently its doing it more and more and a couple of scary moments getting onto roundabouts and junctions is now more than irritating.

i guessed it might have somthing to do with the EGR but then thought it was as if the throttle wasnt taking to the engine.

Other site users seem to have the same idea.

The croma ( 56 plate 150bhp 16v) is going back to the fiat dealer this friday. Will keep you posted if they find anything. (They better!!!)
 
Just a earlier tha expected update.

My engine warning light has just come on with the display saying "check engine"

Also its been stalling with the word "inefficient oil pressure"

Lets see what happens tomorrow eh?
 
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