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Discussion Starter #1
hi all
read up on what can cause sluggish performance at low revs, MAF been main suspect but on poping a new one in mine it made no difference except making it smoke more

took it to alfatech in town, nice chap there said his jtd was just like mine and it was the "EGC" valve or something similar, something to do with exhaust gas recirculation, a local diesel specialist diagnosed the fault and blanked the valve off at a cost of £90

just wondering if all that made sense and if its as easy as blanking off, it must be a job that can be done "DIY" as anyone done it and have pics etc to show ins and outs

oh the car may be fine for a couple of days......then itll start......allways seems worse if ur sat at lights for a while

look forward to any feedback

Gary
 

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Try unplugging the EGR valve but I don't think that works on Alfas.

Could be your turbo wastegate sticking open?
 

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Discussion Starter #3
contacted a diesel engine specialist today, think im going to take it over monday morning as itll be easier for them to check if it could be one of a few things,or possibly a combination of things, car as been fine yesterday and today LOL

Gary
 

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What fuel are you using, I found some fuel really bad,

Its noticably slower with standard diesel and there is a big flat spot jst 2.5-3K, with bp ultimate D its almost gone.

In france at christmas it ran really well on any fuel. They do vary the mix between summer and winter to prevent it sludging.
 

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reanimator said:
hi all
read up on what can cause sluggish performance at low revs, MAF been main suspect but on poping a new one in mine it made no difference except making it smoke more

took it to alfatech in town, nice chap there said his jtd was just like mine and it was the "EGC" valve or something similar, something to do with exhaust gas recirculation, a local diesel specialist diagnosed the fault and blanked the valve off at a cost of £90

just wondering if all that made sense and if its as easy as blanking off, it must be a job that can be done "DIY" as anyone done it and have pics etc to show ins and outs

oh the car may be fine for a couple of days......then itll start......allways seems worse if ur sat at lights for a while

look forward to any feedback

Gary
HI Gary,
I took my brera back to my dealer and asked about the bogging down that I was experiencing from time to time. I've posted a link to the Brera forum that you might be interested in. The wikipedia entry in particular is good, note the warnings about emissions testing.

http://www.alfaowner.com/Forum/alfa-brera-gtv-and-spider/65236-took-my-brera-to-the-dealer-today-for-few-problems.html#post876468

I guess I'll know in a few weeks if the problems are fixed by a new EGR.
 

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Discussion Starter #6
just an update

i have the rocket back again today ;-) took it in to diesel specialist this morning at 7am and they fixed it while i waited.
the airflow reading was wrong, way low but not faulty maf unit it was the egr valve, or should i say the egr system, they blanked something off but it still alows gas to circulate or the car would go into limp home mode he said

they had it on diagnostics and that also showed a fault with one of the injectors, so ill be looking out for one.......anyone know any cheap places ???

so to recap on my problem
the car reved slow and was poor at take off upto 2500 revs and blew smoke out when it got revs up, it was stangely intermittant and would be ok some days, a new airflow meter did nothing, good job it didnt cost a fortune £40 brand new off ebay,bloke who fixed car said they get em for £32 alfa charge over £200!!

it cost me a total of £60 + vat and i had it done at "Feathers" on the lowfield industrial estate at ellend just of m62.
hope this may help someone else and stop them throwing money at the car when its not needed

Gary
 

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Morning ,

my GT Jtd used to fly , then after having a clutch fitted by main agent the symptoms and lack of performance sound as yours did - who did the repairs and waht did they do - I presume it is now back to it's proper smoke free performance ?

cheers
 

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I had quite similar performance problem to you reanimator. I tried the maf, blanking egr, alfa delear etc etc and in the end it was only the air filter. Because its not so easy to change it was the (obviously) last thing I tried. So a £10 fix cost me about £250.
 

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Also as for dodgy airflow readings, this also brings the Lamda into contention, or even split hoses, a split hose is the most common fault on TDs and the smoke created by such a little gash is clearly visible, this also give you airflow problems and power is significantly down too.
 

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Was your check engine light on? It should be if its an EGR problem.

Mine is and when hooked up to an OBD reader its shows as EGR fault. Car (147 1.9 JTD 16 valve) is sluggish and smokey at low revs, but neither above 2500. Think I need a new valve (got over 100k on the clock). Its not good to blank it off, it might fail the MOT on emisions and it can cause carbon build up.

It wont be anything to do with the Lambda as diesels only have simple oxidation catalysts not complex 3-way ones like petrol, so theres no Lambda sensor.
 

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No egr light on , I am thinking it may be a split or misrouted hose as the car was spot on b4 clutch fitment and now this - it looks like there a plenty of hoses and pipes near the clutch/gearbox area -performance wise the car is a shadow of its former self ! :cry:
 

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When blanking off EGR you also need to disconnect and plug the vacuum to the butteerfly in the inlet manifold, or else when it closes it will try sucking air in through your valve stem oil seals as there is no where else to get it from.

BEWARE!
 

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sorry jasons but I couldn't agree with you...
I also think the same as you do...long time ago
but I tried to find out what is happening...
this is what you can see in eLearn software for Alfa 156
the same goes to 147
and we really did monitor this butterfly and it REALLY works only during switching off....

EGR does not need help (in form of closing butterfly) to pump exhaust gas in inlet manifold...
pressure in exhaust manifold IS bigger than pressure of air coming from Garrett...

ergo: there is no need to shut off butterfly in case of blanking EGR, it will remain open all the time except when switching off the engine
 

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sorry jasons but I couldn't agree with you...
Could this be confusion between the 1.9 and 2.4 GT diesels ?
I have read jasons posts on this subject many times and some of the comments dont seem relevant to my 1.9. There is no vacuum connection between my egr and the throttle butterfly. And yes my throttle butterfly only moves on key off.

I stand to be corrected here as I am no expert and jasons seems to know what he is talking about.

What are the differences between 1.9 and 2.4 diesels ?
 

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mainly turbo edition is different in 1.9 vs 2.4:

- 1.9 8v JTD --- EURO 2 -> Garrett GT15
- 1.9 8v JTD --- EURO 3 -> Garrett GT2256V

-1.9 16v JTD --- Garrett GT1749V

-2.4 10v JTD --- EURO 2 -> Garrett VNT25
-2.4 10v JTD --- EURO 3 -> Garrett GT2256V

-2.4 20v JTD --- Garrett A/R.53
 

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hi all
read up on what can cause sluggish performance at low revs, MAF been main suspect but on poping a new one in mine it made no difference except making it smoke more
This doesn't make the least bit of sense... The sole job of the MAF in a diesel is to act as a smoke inhibitor, so a new one should make it not smoke at all! did a genuine part get fitted? Next time it feels sluggish, unhook the MAF completely and see if it drives better. When the MAF is not connected the ECU will rely on it's internal tables to look up the correct amount of fuel to inject. This means it will get more fuel than with a knackered MAF, but also that the car is more likely to smoke...
 
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