Hei! I'm not sure whether this is a problem or not but at around 2000 rpm the boost pressure decreases, specially in 4th and 5th gear. The car is a JTD 8v 115hp 2003

I did some runs with the FiatEcuScan connected and this is what I got:

4th gear pull


Another 4th gear pull


And a 5th gear pull


All of this are with full throttle.

So, is this normal? Anything I need to check?

Thanks a lot!

looks like the ecu is intentialy cutting boost due to the overboost spike.
to start easiest and cheapest is to remove and clean map sensor in the inlet manifold to be sure its a true reading, theyre usually pretty cruded up if never been cleaned(I use carb cleaner sprayed into sensor basket)
then search for some threads on stuck/seized vnt vanes.
you need a few visual checks on the turbo actuator movement when switching on and turning off engine(if you watch and someone else key ign)
depending on what you see there will determine where next.
you could have normal vnt arm movement (approx. 10mm) or you could have no movement or reduced movement both may lead to overboost when accelerating.
this may lead to boost solenoid tests for pipework leaks or inability to relieve vac when requested by ecu( boost solenoid 20% is min boost position, so when it dropped to 30% on last log boost should be dropping quickly yet it was still increasing until it looks like ecu cut boost or fuel then when it dropped below requested spiked up again)
looking at those logs id guess stuck or sticky vnt vanes or boost solenoid stuck in max spool position or unable to vent vac.

this is all if its a standard car, not mapped or boxed ?
if it is especially box ,that sort of overboost is not uncommon and if so turn it down to lower setting.

That is Good info there sussexa , im off outside to see if that will sort my Little problem i have

sussexa said:

this is all if its a standard car, not mapped or boxed ?
if it is especially box ,that sort of overboost is not uncommon and if so turn it down to lower setting.

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The car is completely standard and now that I think about it, I've had an Engine fault warning light a couple of times when accelerating at full throttle in 3rd gear and it disappears as soon as I lift the throttle. After checking with FiatEcuScan I got an error stored that said something like "Supercharger signal fault".

Unfortunately I don't have the tools or the space to check the car, so I'll have to wait until next week when I go to my in-laws' place.

Thank you!

Have you got to the bottom of this problem ? as I have the same problem, mine puts engine failure on dash and error code P0235 which is boost fault

croy said:

Have you got to the bottom of this problem ? as I have the same problem, mine puts engine failure on dash and error code P0235 which is boost fault

Click to expand...

As I said before, I don't have the tools nor the space to check the car, so I'll do it in the weekend but try following the advice given in this post and maybe you can fix it before me! First thing I'll check is the MAP sensor though

Hey! I was wondering... what if I have a problem with the vnt arm mobility... then what should I do about it? WD-40? or what?

By the way, I cleaned the MAP sensor but it didn't help with this issue

Thanks!

I had the same problem .. mine was the EGR , my egr plate had failed , so made a new blank up and fitted it , and its sorted the problem