S16 Avac System

[eddie_1.9 1]

I think it called AVAC? It on a S16- it's the double inlet system controled by a vacuum. It seems it is some how controled by the ECU via a solinoid mounted on the side of the head.

From the solinoid, one pipe goes to the butterfly diaphrams, one goes to the vauuum pomp, and there is a pipe connection on the back end of the solinoid. On my car there is no pipe on here. I'm told there should be one that goes to somewhere on/through the bulk head. Does anyone know where?

[Richie-Van-GTi 71 2 Cars]

It doesnt go anywhere, the solenoid switches from ambient air to vacuum which is what opens the AVAC diagphrams.

the pipe that runs along the bulkhead on the S16 is from the charcoal canister solenoid in the RH wing and goes round to the inlet manifold.

[eddie_1.9 1]

Oh i see, thank you I guess my solinoid must be duff then as my diaphrams arent working but that end of things is fine. If i rev the engine i can feel a slight vacuum/suck from that back hole on the solinoid, do you know if that indicates anything?

Edited April 4, 2006 by eddie_1.9

[Miles 331 1 Cars]

They quite often fail, Does yours run the Vacume chamber (Under the control valve) of the Vacume Pump? (End of the inlet cam)

[eddie_1.9 1]

Yes thats it!

Also, i've just got the S16 and joined the GTi-6 and rallye forum. Last year (July 05) 'miles' on there (i think thats probably you?) posted a thread about the AVAC system pipe work: here. Did you work it all out in the end? can you confirm that my pipe work on the solinoid is correct with the rear connection open?

 

 

I just pm'd you on PSOOC about the wheels too

Edited April 5, 2006 by eddie_1.9

[pugrallye 0]

this random pipe isnt the map take off for the ECU is it?

[eddie_1.9 1]

No, that comes fron the front of the manifold to the side of the battery box then into the ECU.

My problem is a lack of pipes rather than too many. It looks like i should have one that i don't.

[Richie-Van-GTi 71 2 Cars]

eddi I'm 99% sure on an s16 conversion I done a few months back that rear connector on the solenoid is blanked off, if you suspect the thing isnt working a simple test would be put your finger on the hole at idle and there should be a slight vacuum, then rev the car and put your finger there. The solenoid should switch over and the vacuum should be redirected to the diagphrams. Or take the solenoid thats used on the charcoal canister pipe and switch them over as they are the same. It could be the pipes on the front of solenoid are the wrong way around. This would allow vaccum through the back at high revs but not at idle IIRC and would explain them not working as they should.

[eddie_1.9 1]

ok i'll go and have a play in a mo during my lunch break. I will try swapping the pipes round and see what happens.

[eddie_1.9 1]

Right, i've had a play and here's a wonderful drawing (i did it myself!) of the offending item:

Where the 2 outlets are at one end is where my pipes are connected, as labled.

I pulled off the pipe on the vacuum pump pipe at the pump end and sucked it but the diaphrams didn't move and it wasn't easy to suck so that must be good as the pipe is clearly not holed then. but there is no vacuum gettin through the solinoid. I guess the solinoid simply pushes a stopper in the end hole of the where the diaphram pipe connects when it wants stop the vauccum to them. mine must be stuck in this position.

Edited April 5, 2006 by eddie_1.9

[eddie_1.9 1]

I've found this article about it too: http://www.aussiefrogs.com/forum/showthread.php?t=7967

it all makes sense now.! I've found out the solinoid is called an 'electrovalve' by Peugeot. Part No. 0000036338. Price is £22.41 inc Vat. (thanks to the GTi6 forum)

 

Its nice to work it all out and understand why its something is not working, rather than just replace stuff all over the place and hope problems go away.

When i get it fixed/replaced i'll post back with results

Edited April 5, 2006 by eddie_1.9