S2 only boosting to 4 Psi....Not the IAT Sensor! Ideas please

[s2dude]

ok guys.
As part of my ongoing work with the S2 since fitting my new Defi rep boost gauge the other day (love it!!) Ive found out why my car seemed a bit gutless over 4 k rpm// (it takes off very well then.......just seems to go flat??!)

and I think the fact it is only boosting to 4 PSi may be a Big Factor!!!

Ok. So I Vagcommed it and the Intake Air Temp sensor was highlighted as faulty...So I tested it and it was ok resistance wise but I found one of the connectors had come unsoldered so I repaired it and NO Vagcom code now..... :mischeif:

BUT// It still only Boosts to BANG ON 4 pis. no fluctuation in that level??

Im suspicious the MFTS might be faulty as the car seems to take ages to get to temp via the gauge but Im not sure.....and it only does 4psi even when in the middle of the temp gauge.

So on to the next idea that the Wastegate Frequency solenoid might be knackered?? though I thought this would limit boost to FIVE Psi and not 4psi??

Any ideas please guys?/

TIA

[s2dude]

Anyone

[Jamo]

Change the WGFV and check the WGFV fuse hasn't blown.

The WGFV being knackered wont electronically limit the boost to 5 psi.
i.e what will be happen is that the car will run off mechanical boost limit of the Wastegate directly.

Also have you checked for boost leaks and made sure the boost pipe to the ECU hasn't popped off?

[Fat Audi 80]

My suspicions would point to the work carried out fitting the boost gauge. As Jamo rightly says, check the boost pipe to the ECU under the dash etc...

Always start with the last thing you changed / repaired / refitted on the car

Cheers,

Steve.

[s2dude]

Change the WGFV and check the WGFV fuse hasn't blown.

The WGFV being knackered wont electronically limit the boost to 5 psi.
i.e what will be happen is that the car will run off mechanical boost limit of the Wastegate directly.

Also have you checked for boost leaks and made sure the boost pipe to the ECU hasn't popped off?

Cheers guys
Ive not tested for boost leaks as yet...but am going to on Thursday after I fit the new WGFV Ive ordered.....

i just cant get my head round the fact it is BANG ON 4psi...always max. Not the 5psi that the wastegate mechanically limits it to....a boost leak would not usually give such predictability IMHO?

Although could the WG spring be "worn" and as a result not maintaining 5psi??

Fataudi80///

Thanks for the suggestion but the boost gauge is fine......it wouldnt read accurately (and correct vacuum at idle) if there was a leak I dont think? but I will double check this pipe to the ECU anyway

Any other ideas guys?

//just ordered £££ worth of various parts from vagparts so the jobslist has grown even more

TIA

[s2dude]

[Jamo]

Have the cam timing checked as if it's out you wont get boost.

Or book it in with MRC for a health check.

[s2dude]

Have the cam timing checked as if it's out you wont get boost.

Or book it in with MRC for a health check.

Cheers mate.

Checking the cam timing defo sounds worthwhile cheers!!!
Will do that tomorrow....while waiting on all the parts Ive ordered