vw caravelle 2.5 tdi 102 lack of power

[shawymoon]

hey guys
hope somebody can shed some light on this i have a vw caravelle 1998 2.5 tdi 102 bhp that has a real lack of power first off i unplued the maf to find that improved a little so bought the new maf installed to find still the same so unpluged the new maf to find that it improuved again so thought that i had bought a duff new maf so whent to vw bought an original new maf to find all still the same also pluged into vag com cleared the codes that the unpluging caoused no fault codes returned .checked all pipes changed the ones that looked to be not so good still the same .striped it down to access the turbo to see if any play in bearings and check the vains all looked good the turbo spins up and blows like normal .anyone know what this problem could be pleasealso changed the air filter.deisil filter maf egr valve wast gate actuator most pipes also timing is bang on with vag com

[bodfish]

On my 2.5 TDi (88) I found that the air inlet pipe to the turbo was loose on the inlet spigot. Seems that the plastic moulded pipe had enlarged over time (heat?) and was no longer sealing on the inlet. So the intake air was bypassing the air filter and flow sensor and generally mucking up the engine management. Replacing the pipe and O ring had it running much more smoothly, and with better mpg and performance. You say you've checked your pipework, but could be worth another look if the layout of your engine is similar.