Problem list B5 S4!!!

[andybnwc]

Hi peeps if anyone can help on these problems i will be very grateful

1. Limp mode everyso often then goes away again after letting off for a while? all pipes n75 egts replaced and only one fault code upper boost limit exeeded.

2. Cruise control sets but as soon as you try to accelerate using the stalk the cruise control cuts out

3. At maximum warp sometimes feels like its getting boost but just wont go like it should , almost like fuel starvasion ie let off throttle and actually feels faster.

4. Airbag light on but cant read controler with vag com?

5. abs light on vag com says rear near side but the sensor is stuck solid lol



Just fancy working through the problems one by one

Any help will be very gratefully recieved
Thanks

 

[Blue_Thunder]

1. Would have expected the Upper Boost Limit exceeded to have been due to a faulty N75. The only other thing I can think of is a problem with a wastgate on one of the turbos. Have you run Vagcom logs to see Specified against Actual boost?

2. My cruise control has always been ********, although I get vagcom errors on it.

3. Sounds like the engine pulling the timing back. Could be due to poor fuelling as this would make EGT's too high. Are you using 98 RON? If not, **** petrol is probably causing knocking.

4. Have you checked both of the sensors under the front seats? They are very prone to coming lose. Disconnect them, reconnect them, then try clearing your fault code.

5. You need a new rear ABS sensor!

Is the car standard?

 

[andybnwc]

Hi the car is not standard and has the following engine mods
Chip -unsure what make as it was custom to run with BMC induction and decat downpipes with full stainless system, full samco hose kit,boost guage

also does the rear abs sensor just pull out?

 

[shineydave]

the upper boost limit exceeded fault can be caused by a boost leak, had this on a pre facelift S4 with a torn throttle body boot. this might account for the feeling that it's holding back.

if you can't connect to the airbag controller then it sounds like either the version of vag-com you have isn't capable of connecting or the airbag controller is toast. you should always be able to connect to a controller unless it's died.

think early S4's the abs sensor just pulls out, later ones have a small screw to hold them in place

 

[andybnwc]

the upper boost limit exceeded fault can be caused by a boost leak, had this on a pre facelift S4 with a torn throttle body boot. this might account for the feeling that it's holding back.

if you can't connect to the airbag controller then it sounds like either the version of vag-com you have isn't capable of connecting or the airbag controller is toast. you should always be able to connect to a controller unless it's died.

think early S4's the abs sensor just pulls out, later ones have a small screw to hold them in place

Hi i changed the throttle body boot for samco after a torn one was found ,that goes for all the boost pipes too.

The abs sensor feels completly stuck unless there is a small screw somewhere in it , Where abouts is the screw ie is it visible?


I got a ****** ebay usb odbII lead and have to use shareware vag com 409 and force dumb mode
my sony vio dont have a serial port will a usb to serial adaptor work?
I also have some chip tuning software and other programs all look for com port 1 i presume this is serial ? im not very good with computers lol
thanks

 

[shineydave]

have you checked the F pipe as well, i was just being generic when i mentioned the TBB, there's plenty of other places boost can leak

 

[andybnwc]

Yeh i replaced it with samco too, i also did a presurre test but could not hear anything either

 

[Blue_Thunder]

I got a ****** ebay usb odbII lead and have to use shareware vag com 409 and force dumb mode
my sony vio dont have a serial port will a usb to serial adaptor work?

You need to download some USB/Serial drivers. Usually you'll get a CD and instructions with the cables. I got mine off eBay and it works fine.

 

[andybnwc]

You need to download some USB/Serial drivers. Usually you'll get a CD and instructions with the cables. I got mine off eBay and it works fine.

I can get it to work with all the usual fuctions of the shareware but just wont comunicate with airbag controller -what shareware version are you using etc

 

[andybnwc]

bump please

 

[andybnwc]

bump again on this please getting sick of dropping boost