02 passat tdi 100 avb lack of power

[cmcb1981]

Hi newbie here so be nice, I have recently got a passat tdi and has been dead no power at all , changed air flow meter and was marginally better but just seemed to be a lot more smokey than before read fault codes coolant sensor which I replaced seems ok now and fault no longer coming up on the computer ( im using the snap on solus fault scanner )and a maf sensor fault code from disconnecting it to see if it drove any better and it did'nt ,now I replaced the maf and was from eurocar parts( I know the cheaper one which is probably cheap rubbish )so I checked the wiring to maf it seems to be getting all the voltages and earth ok but the out put signal seems to be not changing when she's revved up so I think I still might have a maf problem, so need a vw one this time lol as well, but checked the 12 v feed to the n75 and it seems ok getting 12v to it, but missing its earth so i gave it an earth feed and definantly feels better, you can feel the turbo trying to work where it normally doesn't work at all so im trying to get a wiring diagram to so I can do a continuity check of the wiring to the injection computer and check where the earth goes to ,Im sorry it such a big long rant but any help would be much appreciated or im going to torch it lol only kidding

[passat 130 tdi]

you've pretty much covered all of my suggestions

[scotty33]

A common cause of low power/boost, is a vacuum leak. disconnect the small bore line from the feed into the servo. suck on the small line to check the system holds vacuum. If not check the small bore piping over the airbox, down to the N75. There could also be a problem with small bore vac piping across the back of the engine bay to the egr solenoid valve.

I don't know which earth point is used, but there are a few behind/below the fuse box, could be one of those?

[caldirun]

Change the head wiring loom.

[cmcb1981]

been busy trying to sort my garden the bosses orders (ie wife lol). So still haven't had time to look at her, trying to locate a wiring diagram for it and I have started to replace the vacuum lines replaced prob about 80% of them so i will Idefinantly try Scotty 33 tip on checking the vacuum lines, back to work tomorrow so will try maybe tomorrow night after work and have another look at her and I think Calderon might have a point ,the reason why I am not getting the earth down to the n75 so will try to get wiring diagram for her and go from there still having to drive her like this, a few hairy moments pulling of junctions and stuff ,thanks for the help guys and will keep you posted on any progress great forum by the way cheers

[cmcb1981]

Got the evening off so managed to get a used good n75 and had already replace most of. Hoses so go stuck on and happy days she is a lot better I am able get up to over 70 in a reasonable amount of time my old 110 afn a4 would still have run rings round her but the happy enough for now ,still couldnt find a wiring diagram but it seems to be ok now at least she is drivable now and my heart is not in my mouth everything I pull onto roundabouts and junctions. I think she may be still a bit Smokey bit I will keep and eye on it over the next few days and get her plugged n to my mates fault scanner to check for any fault codes / block readings read so fingers crossed she will be ok so thanks for all the help folks great forum:-D

[cmcb1981]

Sorry for the bad grammar , letters and words missing bloudy smart phones lol thanks for all the help folks.