AEB Guru Needed...Boost Problem
Thread Starter
AudiWorld Member
Joined: May 2009
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AEB Guru Needed...Boost Problem
i have tried everything ppl have told me...im a turbo noob...so be gentle
ok guys...im pulling my hair out with this. i have been chasing this problem for about 2 months....
im having a low boost problem. i have spoke with a few of you to help and have done everything i have been told so far...
have checked n75...ok
have checked for boost leaks...none
installed new maf sensor...logged with vagcom and at max is only 106 g/s...i have been told it should be closer to 120 g/s?
NO MAP Sensor
WHAT COULD IT BE???
Something must control the n75 which controls the turbo psi...what sensor(s) control it? or how can i fix it?
please help...im ready to drive the car into a pole. i used a MBC, but it drove very bad at part throttle...it ran awesome at WOT. thanks for any and all possible assistance
ps...its an early issue 99 Audi A4 1.8T...which im finding out is different than a VW Jetta/Passat of the same year...TIA
ok guys...im pulling my hair out with this. i have been chasing this problem for about 2 months....
im having a low boost problem. i have spoke with a few of you to help and have done everything i have been told so far...
have checked n75...ok
have checked for boost leaks...none
installed new maf sensor...logged with vagcom and at max is only 106 g/s...i have been told it should be closer to 120 g/s?
NO MAP Sensor
WHAT COULD IT BE???
Something must control the n75 which controls the turbo psi...what sensor(s) control it? or how can i fix it?
please help...im ready to drive the car into a pole. i used a MBC, but it drove very bad at part throttle...it ran awesome at WOT. thanks for any and all possible assistance
ps...its an early issue 99 Audi A4 1.8T...which im finding out is different than a VW Jetta/Passat of the same year...TIA
Thread Starter
AudiWorld Member
Joined: May 2009
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i have been checking it today...i pushed up the piston and held the vac nipple and the piston went down. then i pushed it up and used a vac pump to hold it and it held. not sure if it is bad, dirty...im not familiar with the turbos yet. can i clean it...i dont have anyone i know to borrow theirs and check. would a bad dv cause a low boost problem? thanks alot...
chris
chris
Mr Mc Feely
Joined: Feb 2003
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When you said tested for vac leaks.. did you actually cap and pressurize the system?
Take the valve out completely. Pull the small vac line from the top. Use a 14mm or so large long socket (something that fits just inside the valve) push the piston in all the way.. then plug the top vac line with your finger.. with the socket removed the piston should not move until you remove your finger. If the piston creeps down. the valve is bad.
Take the valve out completely. Pull the small vac line from the top. Use a 14mm or so large long socket (something that fits just inside the valve) push the piston in all the way.. then plug the top vac line with your finger.. with the socket removed the piston should not move until you remove your finger. If the piston creeps down. the valve is bad.
Thread Starter
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yeah...i capped with pvc cap and made a coupler like the DIY lists...
i did test the DV yesterday...here is what is did...
i pushed up the piston with my finger and held my thumb on the vac nipple. the piston immediately dropped. then i pushed up the piston with my finger again and used a mity vac pump and applied vac to the vac nipple. when i did that it held. i first went with 15 vac, then down to 10, then down to 5 and it held the piston.
so...is it bad? the finger trick didnt work, but the vac did??? im not sure how this works, or for that matter the turbo...any help would be appreciated.
i did test the DV yesterday...here is what is did...
i pushed up the piston with my finger and held my thumb on the vac nipple. the piston immediately dropped. then i pushed up the piston with my finger again and used a mity vac pump and applied vac to the vac nipple. when i did that it held. i first went with 15 vac, then down to 10, then down to 5 and it held the piston.
so...is it bad? the finger trick didnt work, but the vac did??? im not sure how this works, or for that matter the turbo...any help would be appreciated.
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Thread Starter
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how can you be sure of that...with a MBC i got 10 psi, when i unhooked the wastegate pressure line, i boosted 15+psi...if there were not a flapper, i would think i would have very little boost in both those situations. i may be wrong, please let me know...