Technical JTD110 poor performance

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Technical JTD110 poor performance

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Jul 25, 2009
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My 110jtd Marea has struggled with poor performance, poor economy and intermittent black smoke under acceleration ever since I bought it 18m ago. It has only done 70k miles and I have replaced the MAF, cleaned out + checked the EGR, changed air filter, checked piping to turbo actuator and performed an ECU reset. I have even had the clutch and flywheel changed at a cost of £700 :eek: because it was starting to slip and thought this might be contributing.

I average about 42-43mpg in mixed driving and the performance up hills etc is such that my girlfriend's 1.2 Bravo leaves me for dust!! It is particularly 'flat' below 2500 revs, after this there is often a surge in performance as if the turbo has kicked in or fuelling has increased but not always.

When the engine is cold it performs much better. I also tried a tuning box which improved performance but worsened smoke.

Any ideas?

Cheers, Andy
 
Cheers mate, didnt realise ECU reading was within the realms of the DIYer; are any special cables/connectors needed and where is the connection point on the marea? Impressive marea you've got there, where did you get the remap done or can you do it yourself with generic data?
 
All the info you need about cables and such is on the FiatecuScan site. Cant remember what year the 16pin socket started think it might be 2000 but you will need to follow the plastic down from the steering wheel and feel if the socket is there otherwise you will have to lie on your back and look back up if it hasnt been disturbed it will have a cover on it. Once you see where it is you wont need to be a contortionist. Oh nearly forgot to mention my remap was done at Red dot at Watford with a rolling road but theres loads of places doing them now, the tuning boxes you can get now are very good, theres a trader on the forum called TMC I think his name is are suppose to be good.
 
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Must admit it 'feels' like a MAF problem as if the car doesnt know how much air and fuel to mix together at any given moment. However performance isnt any better with the MAF disconnected. I have bought a non-genuine MAF from ebay though...

I dont know anyone with a JTD110 but I have got a friend with a 115 stilo and I have a feeling they share the same MAF?

Anyhow, am awaiting arrival of the VAGCOM cable and will run the FiatECUScan software to see what that throws up.

Thanks again for everyone's assistance.

Andy
 
complete maf failure can give the same performance as disconnecting it.
Be wary of cheap ebay maf too, I bought one and it just didn't work ended up having to bite the bullet and goto the dealer for one. :(
 
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Try cleaning it with electronic contact cleaner?

I'm going to be doing this on my 1.6 sx soon! (Before i start juggling with the injectors anyway!)
 
Best use a cotton bud and make sure you squeeze most of the cleaner out of the bud . The MAF wont like being soaked.


Eeek, from what i've been told the MAF wires are extremely thin, cotton bud pressure could cause irepairable damage from what i understand, the suggested spray you can also get as a specific MAF cleaner, but what the spray does is i think dry out all dirt etc etc, and then completely evaporate it if you get me, leaving no residue on the electronic contacts.

You spray aload on, and then let it air dry and that should solve the problem.

I think what tends to happen is the wires in the maf are heated, and the air cools the wires changing the resistance levels and then feeds the input to the EC? but when it gets dirty, your essentially blocking the air from performing its task of changing the MAF resistance.

But if you've used buds before then a light hand should do the trick!
 
Ok, have performed an ECU Scan and their are no fault codes.

The only real finding is that the boost pressure is consistently lower than the 'desired boost pressure' except over 3000rpm which is where the power kicks in and the car emits a huge plume of black smoke. I have cleaned out and tested the EGR and even tried blanking it but this doesnt change matters. I cant see any vacuum leaks. Are there any other sensors etc which control booster pressure?
 
if disconnecting the MAF sensor makes no difference then this is most likely the fault; won't show up on diagnostics unless completely stuffed....
had to buy a couple on ebay before I got one that worked and that was the multipoint one that seems to be the same, dunno abot the 115 but could try it.....
 
if disconnecting the MAF sensor makes no difference then this is most likely the fault; won't show up on diagnostics unless completely stuffed....
had to buy a couple on ebay before I got one that worked and that was the multipoint one that seems to be the same, dunno abot the 115 but could try it.....

I think you have that wrong, if disconnecting tha MAF does make a difference (it runs better) then the MAF is faulty.
 
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