JETaah
Vendor , w/Business number
Hello, My 1999 1.9 TDI goes into limb mode when going up an incline at around 3000 RPM. I can also make it do it on the flat if I put the pedal to the floor. It will also idle rough when you are have the clutch in slowing down to stop. Once stopped, it goes back to a normal idle. I have replaced the wastegate valve, turbo boost solenoid and cleaned the mass air flow sensor. Any ideas would be appreciated.
Better to put this in the MK4 section but since you asked....
Diagnose it by reading the fault codes first. You may have replaced everything but the faulty parts.
I would look to see that the the turbo actuator moves freely. It is liable to be in a position where it is stuck or does not fully open.
The other problem is most likely related to too much fueling, A simple adjustment of the injection pump would be all it needs. (Hammer mod)
Both of these subjects will be covered in the list of How to section.
turbo repair -- if it is not the actuator alone jamming things up
http://forums.tdiclub.com/showthread.php?p=1340914
turbo actuator:
https://www.idparts.com/vane-actuator-vnt-15vnt-17-a4-alh-p-530.html
hammer mod -- you would need to have VCDS software to accurately adjust it. On older cars this might induce a fuel leak due to disturbing flattened gaskets. Have a gasket kit on hand.
http://forums.tdiclub.com/showthread.php?t=258297
gasket kit:
https://www.idparts.com/tdi-injection-pump-seal-kit-2467010003-p-1143.html