Vacuum/Pressure testing (?s).

[jameswkr]

Just got my Mityvac from Premier tools. I have previously pressure tested TBV and wastegate actuator. Car ABY S2 Coupe. 4 questions:-
1) How much vacuum should be applied to the (lower) split tree at the rear of the IM to test ? 2) How long should it take for the vacuum to pump down ? 3) On this tree, one branch connects to a light pink hose that appears to go to the ECU/recirc valve - the other goes to a larger diameter hose that routes round the front n/s wing - where does it go ? 4) The upper rear hose connects to a valve (?) just in front/below the throttle body - is this the fuel vapour system or something else? Still learning! Thanks, James.

[S2central.net]

Haha - that is a secret

No really I need to explain this properly for you and others and I'm just about to nip out of the office for a quick sherbert.

Basically there are two lines which come off the rear of the IM on an ABY.

One goes to a T-piece where it splits for the FPR and then via the green tube to the ECU (via a small moisture trap).

The other goes thru another T-piece (on A/C cars) where it goes thru a check valve (to block boost pressure) and into the recirc flap control on the A/C. The other side of the T picks up the pink hose to go into a vacuum reservoir which serves the rear diff controller (also with another check valve under the rear seat).

Not sure that text is 100% accurate but you'll get the idea - look for a sticker under your bonnet which shows the hose routing

On 3Bs there is an additional little hose line which runs from the rear of IM to the TBV.

Can take you thru the MityVac process in person at CastleCombe if you want.

Cheers,

Paul

[jameswkr]

Thanks Paul. All appear to check OK. The lower tree ( not the FPR) one, appears to have a vacuum regulator (?) it held steady at 20" but would not pump down any lower. All other connections would go to the limit of Mityvac ( 23-25"). Thanks for the C Combe offer, hoping to get there and meet some listers. James.

[S2central.net]

Here's a doodle I did on the train, attached...

[Peter Dyer]

try this:

http://www.sjmautotechnik.com/10vwaste.html#wgcnt

Pete

[S2central.net]

Nah - that's not relevant for the S2.

Trust me - my drawing is better

Paul