Connecting egr vac controller backwards

[Upex]

Folks,

Anyone know what the effects would be of connecting the egr vacuume controller backwards, ie vac pipe to egr spout and egr pipe to the vac spout?

[graemeX5]

Hi

I am not really sure, but I would think that the controller wouldn't work correctly, poss even in reverse.

I will leave it to one of the others such as X5Sport or Horizon to confirm this for you
Graeme

[Horizon]

[quote="Upex"]
Folks,

Anyone know what the effects would be of connecting the egr vacuume controller backwards, ie vac pipe to egr spout and egr pipe to the vac spout?
[/quote]
It all depends on the valve configuration. If the valve is just a two port/ in out. Normally closed or normally open valve ( normally closed means it's closed until power/12v is applied. Normally open is when the valve is open until the power/12v is applied which then will close the valve.)
The trouble with the two port valves is that if it is opening an actuator/ diaphragm just cutting the vacuum supply to the actuator/ diaphragm, it will not allow the actuator/ diaphragm to return to its other position as the air/ vacuum is still in the pipework, so still pulling on the diaphragm.
So a 3 way valve is needed, which when the power is taken of the  valve it switches to position 3 ( exhaust )which allows the air/ vacuum to be return to atmospheric pressure allowing the diaphragm to return to its original position.
So under power port1 general vacuum supply will be open to port 2 allowing the diaphragm to operate and overcome the spring in the device.
Take the power off and port 1 ( vacuum supply ) is isolated and the valve switches over joining port two ( diaphragm) to port 3 ( exhaust ) allowing the vacuum in the diaphragm to return to atmospheric pressure, so the spring then returns the device to the closed position
Port 3 won't have a pipe attached and may just be a drilling in the valve block, sometimes with a filer on it to stop crap getting in.
So to get to the point

[Upex]

Lol, thanks for the info.

Makes sense, and I assume we have 3 ways, otherwise as you say, the egr wouldn't shut again. Plus they have a filter on, which I did wonder what that was for lol.

So, a good one, should hold vac (applied at the vac line) until it's driven with power, or not ifs it's a normally open one?

Which do we have on the x5 e53?

The one I put back on only held vac with the out (egr) port blocked, if I left that open, it drew air right through and could create a vac. If it's a normally closed, it's therefore toast? As isn't closed as vac is going from vac inlet to out port without power?

The new one held vac at the vac port without being covered so sounds like it was working as a normally closed one would, but this threw an error code, which the old suspect one didn't....

Guess I need to know if it's a closed or open one first then can delve further.

Also, found a pier burg test pdf that said the ele plug should have battery voltage when running, mine had 9v, so not sure if it's low or it runs at 9v to keep it closed and when needed drops the voltage to allow it to open and create vacuume at the egr?

Guess I need to figure this out, as have one of these new units in the turbo to (so if the egr one threw an error immediately, perhaps the turbo one not working as it should either?

[Horizon]

Normally open you will be able to blow through the valve when it's not connected to the power from the car . ( port 1 to 2 )
Normally closed you won't be able to blow through port 1, but if you blow into port 2 the air should come out of the exhaust filter.

[Upex]

Cheers horizon, will give it a go on the old one and new one that are off the car to see what's what. Wish I understood how these things are supposed to work, as life diagnosing would be much easier lol.

Any ideas if the voltage is ok at 9v odd versus pier burg saying they should be 'batter voltage' at ele connector?

[Horizon]

9 volts seems odd. I remember when the old type ignition coils used to run at 9 volts via a ballast resister , I think that was to cope with starting voltage dropping whilst the starter was engaged.
I've come across voltage drops due to burnt relays on circuit boards that supply other external components.
The board that supplies the vacuum or a bad connection may be to blame.
Are you thinking the EGR / vacuum problem could be related to your original loss of power problems ?
If you have stripped and cleaned the EGR valve and made sure it's sealing you could blank the vacuum pipe to the EGR controller valve to eliminate this by technically bypassing the EGR system.

[Upex]

Well, kind of yes.

Turbo didn't solve it at all (despite being duff), it's only after I've changed the vac controllers that things got better and error cleared.

Given that the new egr vac controller threw an error, the old controller has allowed much more power, but I do not know which old controller was which.

So either I've added back in the old turbo controller, or the old egr controller which has made a lot of difference.

If the former, then the egr controller was at fault and I'm just moved the turbo to egr, and replaced turbo controller.
If the latter, then the turbo unit was duff and has been replaced, with egr being as it was.

Given the utter crap response when egr pipes were back to front (plus think that new controller is duff was pinging vac pressure at idle between .5 bar and zero) it clearly (in my mind) plays a part in the power issue (either directly or via codes) so can only assume power loss was releated to egr controller in some way.

Wish id been more sytematic, but having removed and replaced everything from manifold, to controllers, even turbo several times over, I was sick of it lol.

Might bite the bullet and buy 2 new vac controller from bmw and fit them (bought cheaper aftermarkets) to see if makes any further difference.

Wish I'd left the vac controller off now, as could swap out and test without removing the bloody manifold again! What a stupid place to put it!

Regards the voltage, any ideas how I can find out what it should be, incase it's not the controller at all, rather it's electrical supply?

Cheers for the help horizon, much appreciated.

[Horizon]

Regarding the vacuum pressure, if you had piped a 3 way valve the Wong way around it would drop the vacuum to zero when the valve wasn't energised as it will be pulling air in through the valves exhaust port, then when the valve operated and ports 1 &2 were joined together, the EGR would open up, but then once the power was removed the EGR wouldn't close as the pipe to the diaphragm could not return to atmospheric pressure because the exhaust was on the vacuum feed pipe.
Not surprised it wouldn't run properly.

[Upex]

Confused, lol.

There only 2 ports (for vac lines) vac in, and out. For the egr/agr I believe that the exhaust (return to atmospheric) is provided via hole in back of the egr, as it the egr will stay open if that hole is covered whilst vac is applied.

Not sure why there a filter on the vac controller then, unless that vents to atmosphere as well?

Will try and blank off the vac pope though, see what happens lol.

[Upex]

This was the new vac controller cycling vacuum

https://youtu.be/EcUC4GEPn_E

Pretty sure that isn't right lol

[Horizon]

[quote="Upex"]
This was the new vac controller cycling vacuum

https://youtu.be/EcUC4GEPn_E

Pretty sure that isn't right lol
[/quote]

Looks like that was piped back to front

[Upex]

I think it was when it was on normally... but perhaps recalling incorrectly