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Help!No boost and DTC on B5 1.8T

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#22 ·
littlegreek said:
Quote from Andy at Ross-tech: AEB has no air pressure sensor, so there's no way to read boost with a diagnostic tool. Aftermarket boost gauge would be the only way to check.
:frustrated:
Click to expand...
He is correct they use barometric pressure I wasn't paying attention...

Ok, so then you have you checke the vac lines to N75, N249, and N112?

Have you made sure your DV is holding vac?

Did you check your wastegate actuator rod?

There's not much to the system it's always something easy.

Any other codes? Do you have a K&N filter on your car?
 
Discussion starter · #23 ·
Ok,pressure tested from the MAF to throttle body=no boost leaks. Cant find any other evidence of leaks as blow by would seep out of any hole,dont see anything of that sort.
I also cleaned out the AIT sensor,just in case it was coated with **** but it was clean.
Also checked resistance for the N75 and measured voltage leading to it,voltage increases as i blip the throttle,so its working.
D/V is brand new 034 piece,i unplugged the reference line to see if the D/V is working,what it did was create surging,which is what should happen as the turbo not being able to spool down from the compressor side,right?Also all 3.5mm vacuum line have been replaced as they were a bit crusty.
Only thing left is the wastegate actuator and diaphragm but i would have to remove the turbo to physically see if the flapper is flapping. What i do see is the rod moving like 1/4 inch when i blip the throttle but that doesnt mean anything if the flapper or hinge is broken,right?
 
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#26 ·
Sounds like you have all your bases covered. I always do all the checks before I condem a turbo I have not done one step and it bit me in the ass hard. If everything you have done checks out electrically, vac lines are new, N75 is new, DV is new, no boost leaks, you see the actuator rod moving so you know it gets vac and the solenoid is doing it's job moving the actuator rod and N75 is doing it's job actuating the solenoid. I'd look at the turbo now. You can remove the downpipe bolts and slide the downpipe back far enough to see if the flapper is gone. You might need somebody at the muffler pulling back while you push on the downpipe but it can be done.
 
Discussion starter · #27 ·
Well,just for the archives,the last thing i did was to wire the actuator rod shut which should keep the waste gate closed=nothing...so that means the waste gate must be broken off.
Im hunting for a k04-15 in the meantime or maybe a gt28rs.
 
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Discussion starter · #29 ·
Looked at frankenturbo and pretty much what the guy did was get a k04,put a larger shaft on it and bolted RS2 wheels to it. Only problems with that are no chip tunes for that turbo that exist...yet and 1100bux is GT28 territory,which chip tunes already exist for that turbo. Still impressed though and id be more tempted if the pricing was a bit closer to a K04 as that what it is,er sort of.
 
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littlegreek
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