Ibiza Cupra 1.9tdi loose power after 4000rpm

Hi Guys,

Sorry for the first post asking some advice immediately a member since 2016 but never posted just following all the way from SA

Need some Advice:
Seat Ibiza Cupra 1.9tdi losing power after 4000rpm as if the fuel fades
Its holding boost though so it is for sure not boost. Its struggles to get to the 5000rpm limiter
Mods
Fmic, GT2260, full 76mm straight pipe, Firads 80%
Replaced so far
In tank pump
Fuel filter
Fuel/vacuum pump next to head
vacuum pump
cupra injectors replaced with injectors firads 80% from darkside

Tried mafless so it is not the MAF sensor

We suspecting cam as well but should that not affect the whole rpm range?
Please guys any ideas what the issue might be

Wiped out cam lobes will produce a lot of black smoke.
This is because on PD engines the affected lobes are either intake and or exhaust.

Injector lobes are usually rollers so they are no concern. So the cylinders receive fuel ok but cannot get enough air to burn it (because of reduced intake valve lift) or it cannot get the mixture out fast enough (reduced exhaust valve lift)

Carlos_TJ said:

Wiped out cam lobes will produce a lot of black smoke.
This is because on PD engines the affected lobes are either intake and or exhaust.

Injector lobes are usually rollers so they are no concern. So the cylinders receive fuel ok but cannot get enough air to burn it (because of reduced intake valve lift) or it cannot get the mixture out fast enough (reduced exhaust valve lift)

Click to expand...

There more than enough smoke till around 3800rpm then smoke get less. Even the file is set to max fuel for this issue.

So if cant be cam what else?
Fuel flow restriction?

You need a proper scan to see exactly what is going on with the injectors, etc. Were the injector harnesses in good condition?

JB05 said:

You need a proper scan to see exactly what is going on with the injectors, etc. Were the injector harnesses in good condition?

Click to expand...

Car was scanned no errors
Injectors are in spec as they are brand new and mapping has been changed
The car boost spot on. @4000rpm it is still 2bar(gt2260)
Synchro angle is set to 0. Was playing with it between -2 and +2 little difference though not much