1.8 20v boost issues

Post Reply
vdub mk1/mk3
Cadet
Posts: 87
Registered for: 9 years 10 months
Location: johannesburg

1.8 20v boost issues

Post by vdub mk1/mk3 »

Hi Gents

i have an issue hoping someone can assist me

i have issues when i go into boost did some digging on the web (YOUTUBE) and traced the issue back to the N75 valve, got it replaced but still have the issue when going into boost the car starts jerking, so i just want to find out is there something else im missing?

im suspecting that it could be the internal wastegate not opening under boost.

any idea from the 1.8t 20v expects?????
User avatar
panic-mechanic
Panic's Place
Posts: 26715
Registered for: 21 years 7 months
Membership No: 79
Location: Benoni, putfontein.

Re: 1.8 20v boost issues

Post by panic-mechanic »

Isnthe issue actually boost ie. Do you have a boost gauge connected.? If you have a fuel pump issue ie. Pressure dropping and the car going lean it will do exactly the same thing.
Stephan van Tonder - Jhb - Putfontein Benoni
'05 Audi A6 3.0L TDI Avant
'09 Touareg 3l TDI
'13 VW CC 2l tdi (repair project)
'05 Touareg v10

Perfect Power dealer. I do dyno tuning.
User avatar
dcmk4
Lieutenant
Posts: 1741
Registered for: 9 years 11 months
Car Make: VW
Car Model: MK7 GTi
Location: Cape Town

Re: 1.8 20v boost issues

Post by dcmk4 »

Looking at old posts it seems it has a bigger turbo which I assume the ECU was not tuned to accommodate
'14 Golf Mk7 GTI
THANAS STG/// ECU&DSG
Littco L380x
All the ponies
Image
User avatar
panic-mechanic
Panic's Place
Posts: 26715
Registered for: 21 years 7 months
Membership No: 79
Location: Benoni, putfontein.

Re: 1.8 20v boost issues

Post by panic-mechanic »

Ah. Yeah it always help to post supporting info.
Stephan van Tonder - Jhb - Putfontein Benoni
'05 Audi A6 3.0L TDI Avant
'09 Touareg 3l TDI
'13 VW CC 2l tdi (repair project)
'05 Touareg v10

Perfect Power dealer. I do dyno tuning.
vdub mk1/mk3
Cadet
Posts: 87
Registered for: 9 years 10 months
Location: johannesburg

Re: 1.8 20v boost issues

Post by vdub mk1/mk3 »

if im not mistaken its a T28 didnt think it would be such a biggish turbo to cause an issue with tuning rest of the engine is stock.

i have a boost gauge and is stable when it happens. ive got a VR6 fuel pump assuming it would compensate for the fuel requirements
User avatar
Killerwatt
VWCSA Member
Posts: 4819
Registered for: 15 years 10 months
Car Make: AUDI
Car Model: S3
Membership No: missing
Location: Brakenhurst

Re: 1.8 20v boost issues

Post by Killerwatt »

What ecu? Any error codes? More details on your build would be usefull. If the ecu is a wideband then fueling shouldnt be too far off. Also if boost is stable then why do you suspect the n75?
Could be coilpacks or plugs as well.
User avatar
dcmk4
Lieutenant
Posts: 1741
Registered for: 9 years 11 months
Car Make: VW
Car Model: MK7 GTi
Location: Cape Town

Re: 1.8 20v boost issues

Post by dcmk4 »

It's an AGU
'14 Golf Mk7 GTI
THANAS STG/// ECU&DSG
Littco L380x
All the ponies
Image
vdub mk1/mk3
Cadet
Posts: 87
Registered for: 9 years 10 months
Location: johannesburg

Re: 1.8 20v boost issues

Post by vdub mk1/mk3 »

using stock management,

the N75 was faulty from the get go, and when i did have it on the diagnostic tool it confirmed it hence it being replaced.

i've recently changed plugs but havent had the chance to drive the car as yet.

will need to try get it back on the diagnostic tool again to see if any other codes come up.
vdub mk1/mk3
Cadet
Posts: 87
Registered for: 9 years 10 months
Location: johannesburg

Re: 1.8 20v boost issues

Post by vdub mk1/mk3 »

correct DCmk4
User avatar
panic-mechanic
Panic's Place
Posts: 26715
Registered for: 21 years 7 months
Membership No: 79
Location: Benoni, putfontein.

Re: 1.8 20v boost issues

Post by panic-mechanic »

Agu with an upgraded turbo and stock management. Uhm. No. You will need to do something to help that management. An upgraded pump will not make more fuel come out of the injectors. You have to change the mapping to correct that.
A T28 is HUGE by comparison to the stock one.
Stephan van Tonder - Jhb - Putfontein Benoni
'05 Audi A6 3.0L TDI Avant
'09 Touareg 3l TDI
'13 VW CC 2l tdi (repair project)
'05 Touareg v10

Perfect Power dealer. I do dyno tuning.
User avatar
ICE King
Cadet
Posts: 820
Registered for: 12 years 10 months
Car Make: VW
Car Model: Polo GTI 20V , Mazdarati
Location: Cape Town

Re: 1.8 20v boost issues

Post by ICE King »

Note to add the AGU has small injectors , and a limited ecu to tune.

how you going to tune for a T28 without supporting mods on a AGU? Power delivery is going to fun on this one.
1992 Mazda 323 B3 - Masala Mods
2008 VW POLO GTI - 76mm DP + 63mm exhaust , induction, FMIC, Thanas Tuned
Post Reply