Low Boost Problem

[rs200]

i was looking on forum and i can't find the answer ...

what can be a problem of low boost. in 4. or 5. gear I try full throttle and they don't want to go over 0,5 bar or 1,5 on dash board .

car is stock 220hp, everything is original. but this was the problem before engine rebuild.

i was thinking before that this is because I have mtm turbo on stock ECU. but now ...?

i read that few people on forum have the same problem, did the fix that or..? somebodie know?

any advice...please...

thanks..

I'l be grateful ...

[S2central.net]

Either of the following terms should help your search.

N75 faulty or fuse blown
air leak or faulty WG
TPS not showing WOT
MFTS faulty - the R pin

[rs200]

TPS not showing WOT

I'm sorry but i don't know what that mean..WOT and faulty WG

on my car; knock sensor x 2, MFTS, distributor rotor and cap are new. the resistance on throtle sensor is fine...

car work fine but dont have the power of 220hp

[vertigone]

WOT = wide open throttle
WG = waste gate

help me now with TPS

[Jamo]

TPS = throttle pontentiometer switch aka throttle position switch


Unless the ecu see the sensor being fully open ( aka WOT ) it won't give you full boost. You need to use Vagcom to check when you fully depress the accelerator you are triggering the WOT code in the ecu.

For reference

http://www.sjmautotechnik.com/trouble_shooting/20vthrot.html

http://www.s2forum.com/forum/showthread.php?t=37937

[visintainer]

have you pressure tested the intake system?

[rs200]

aha.. ok ...

now i understand what it is..

i read all treads in those links

thanks Jamo...

[rs200]

hy, people .

today I was finally get some time to do some tests on electrical parts on my car.

well this was happend:

TPS.... 1000-2650 ohm.

I was reading on SJM page that it have to be from 1000-2800 ohm, well my is for 250 ohm less than it have to be. can that be a problem for a low boost (0.5bar)



ALTITUDE SENSOR:
1---2 - 1040 ohm
1---3 - 2540 ohm
2---3 - 2400 ohm
is that ok ? I think it is.. or?

and now ...
I try to find out how much ohm have to be if I want to mesure N75 sensor .

my measures of N75 is 27,2 ohm. is that ok ?

and yes I thy to find any leek on sistem . everything is ok .

can somebody sad is something wrong on this measures.

do you have any idea what can be a problem?

please help...

[Ruffiano]

Hmm interesting, so paul, low boost could be caused by the mfts? I currently hasve an rs2 turbo and manifold on my coupe and I'm only seeing 15 pounds of boost at wide open throttle, I'm curious if my "r" pin is wired in correctly with thle rest of my system...

[rs200]

my MTFS is brand new.

what is "r" pin?

[rs200]

do you think that the "r" pin is 4. wire on MTFS conector. I don't know why but on my MTFS have 3 pin and 4 wire on conector. is that normal or what? that question I want to asked long time ago.

[quattro20v]

Thats the new version of the MTFS. It's missing the 12v line but it doesn't need it anymore. Your sensor is OK.

Try to take a drive with the connector disconnected, did the boost come back?

[rs200]

i didn't try drive with disconnected MFTS. but i will try.. what can I expect?

[rs200]

hy people i finaly fix my problem wit low boost (0,5bar) on stock engine.

the BOV was problem. they have a little lick on rubber inside.

now is finally stock 220hp and 0,9bar of boost pressure..

if somebody will have a same problem , check your blow off..ff.f.

[rs200]

people please help... (again)

now my car have very strange BOOST PROBLEM...

in some case my car don't want to go in BOOST.. only 0,2 bar

then few mile's later they normally go to 1.5 bar (like it have to be)

and the same problem again and again....

what can be a problem ? some wire or it is mehanical error ?

I don't know where to take a look? had someone similar case?

any advice is welcome..