Our 03 16v 1.9JTD Multiwagon has us completely baffled. Have searched this site and think we have done all suggestions after getting power dip when driving. Looks like many people have this problem which in our case is while at 2-3000 revs when accelerating or going up an incline. The car has only dipped power it has never actually cut out and no warning lights have ever lit up.
Replaced the whole accelerator pedal when diagnostic machine said fault was on the petentiometer!!!! No joy. Cleaned the EGR of sooty build up - solonoid moved freely. Problem still there. Tried removing MAF sensor - problem still there. Blocked off EGR - still no improvement.
Has anyone any ideas please cos this is driving my husband crazy. Just thankful we dont live near Beachy Head!!!!!!
:bang:

usually the dip in power is caused by a defective EGR valve. As you have rules this out i wouldnt know what to suggest next. Is there excessive smoke under harsh acceleration? And is there a loud 'whoosing' sound besides the turbo?

Thanks Oakley
There is no excessive smoke or wooshing sound. Think we will have to send it into Fiat. It is at least drivable unlike the problems we had last year.

anbax1953 said:

Thanks Oakley
There is no excessive smoke or wooshing sound. Think we will have to send it into Fiat. It is at least drivable unlike the problems we had last year.

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There seems to be members reporting all sorts causes for this - MAP - MAF - EGR - or Split Intercooler hose.

You said you disconnected the MAF? But did you clean the contacts with a contact cleaner before putting it back on? always woth a shot. I have this issue to with my car and have cleaned EGR and MAF and checked for split pipe and havent come up with a fix yet. So if you find a fix with fiat post it up in here.

anbaz1953,
I would advise your husband or your garage to check all the pipework and connections leading to and from the overboost valve, including to the small black plastic box that is situated on the bulk head in the centre of the engine bay. It has 3 or 4 ( i think) small black pipes coming out of it with rubber connectors.
I had a similar problem for ages but had a warning light with it. Since pushing all these, it has 99% better.
Do a search for "overboost valve" and you'll find a whole host of info.

If that doesn't work, maybe consider replacing the valve completely.

Thanks to all who have tired to help us. The Fiat service manager pointed us to the small part at back middle of the inlet manifold which we think is the MAP sensor (Bosch part no 0 281 002 510)
It was well gunged up with thick black oily substance. When cleaned and replaced the car ran smoothly but that was only a 5 mile run. Car now at local garage for MOT. When we get it back and do longer runs hopefully that will be the end of the problem but I have fingers crossed and will report back soon.
Once again thanks for all the help

yeah - do post some findings when the car has had a run in

You dont have a brick wall I can bang my head against have you. We spoke too soon. Car was playing up on the way home from the MOT station. Will now check out the info on the overboost valve.
:-(

anbax1953 said:

You dont have a brick wall I can bang my head against have you. We spoke too soon. Car was playing up on the way home from the MOT station. Will now check out the info on the overboost valve.
:-(

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No way. I'm sure you will get to the bottom of it. You have had all the parts replaced which usually are the cause of this issue.

Did you say you have checked all the pipework for cracks/splits. Usually the Intercooler hose.

Maybe the clue you are in need of is in your own Post above...?

"The Fiat service manager pointed us to the small part at back middle of the inlet manifold which we think is the MAP sensor (Bosch part no 0 281 002 510)
It was well gunged up with thick black oily substance.

How is the cars oil consumption? Could your turbo be letting oil past its seals maybe?

Thanks Oakley28 and Ffoxy.
Hubby has gone away diving for the weekend (in the other car) so will get him onto it again on Monday.
Its been the most troublesome car we have ever had and he's had enough of it so it will be going up for sale as soon as it is sorted.
Have fitted so many major expensive part its almost a new car!!!!!!!
Cheers Ann

Have any of you any idea why the car runs smoothly with no power loss when at hicher speed cos that fact has us baffled.
Ann x

It does sound like an Intercooler pipe or something

every JTD (and diesel engine) seems to have the oily gunk in the inlet manifold, it naturally builds up on all of them. It builds up (i think, correct me if im wrong) due to the vapours coming from the oil breather pipe, this releases build up of oil vapour and gas from the crank house/head and pumps it into the air intake, after the air box, into the MAF sensor pipe, its meant to collect the majorty of oil but none the less some will get sucked through by the emense suction of the turbo, this vapour mixed with the soot received from the exhaust gasses recycled back into the engine from the EGR will make this slug, i beleive anyway.

with the power loss, does it only occur when you accelerate hard, if your driving gentley is it less frequent?

I had a power loss problem on my 115Bhp, although i got a warning message and mine was due to a clogged up overboost vavle. Liek the guys said above i would check for splits in the intercooler pipes and all of the pipes connected to over boost valave (if you look at your turbo you will see a thin black rubber tube comming from the underneath of it, follow it to the overboost valve). i would try the pipes and cleaning the valve or replacing it, from what you said above it sounds like the only thing you havn't tried.

good luck

Stu

Hi guys
The car is going to the Fiat dealer this afternoon to see if they can pinpoint the problem. Will report back later
Ann

anbax1953 said:

Hi guys
The car is going to the Fiat dealer this afternoon to see if they can pinpoint the problem. Will report back later
Ann

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My car is exactly the same. Pre-Turbo its faster to run the car goes nowhere foot down in second and takes a life time to get revs. When they are there though it flies. Cleaned my EGR once, didnt solve the power loss but did solve the smoking a bit. So it really must a split in a pipe somewhere.

Well the car is home, the problem seems to have been solved and we are kicking ourselves for not going straight to the dealer for a diagnosis.
Our friends examiner threw up code P1555 'accelerator brake feasibility' so his mechanic ordered us an accelerator pedal which incorporated the potentiometer at a cost of around £80. When that was fitted the problem was still there so came to this site for ideas.
Turns out according to Fiat that the problem was the brake not the accelerator. The ECU was reading that the brake was pressed when it wasnt therefore there was a fault with a switch which the mechanic at Fiat has adjusted for us. If it happens again he advises to fit a new switch which will only be about £15. It is not the first time he has found this problem.
The problem causes a loss of power as the ecu thinks the brake is beign applied and cuts the fuel.
Hope this info helps some of you who seem to be having a similar problem

Hi all.
The Stilo hasnt missed a beat since the brake pedal switch was adjusted and we have done quite a few miles now so we are keeping fingers crossed that the prob is sorted.
Thanks to all for your help and advice

anytime. Might change mine. Cant do any harm. Although i think my prob is diff to yours but with similar outcomes. Glad you got it sorted anyway