Secondary air system question on a 3.0i

[kevinkay]

This is the the graphic/schematic on RealOEM.com for my car - 04, E53, 3.0i

I have the larger hose (hose not pictured but you see the large port) into #1 but NOT the smaller hoses or even the port for #3/4
And I don't have #5

My #7 goes into the firewall

I am working on solving a code that others have said there #3 hose was rotted/leaking and I don't even have it!
any others missing this line?
THANKS

[cn90]

- Maybe your small vacuum hose is cracked and broken off, this is why you don't see it.

- I fixed my SAS system in my 1998 528i and wrote it below. You can find some useful info in that DIY:

DIY: Troubleshooting S.A.S. and How to Replace the Famous Fuse # 107! - Page 3 - Bimmerfest - BMW Forums

[e39_touring]

The later 3.0's don't have that smaller hose - it's a different system. The valve is opened by pressure from the air pump and not a vacuum solenoid like in the earlier system.

You can test the valve by taking it off the car and blowing through the big hose port. If you can't the valve could be stuck, and you might be able to unstick it by cleaning with carb cleaner or the like.

The air pump should come on for the first 30 seconds or so after a cold start. If you disconnect that big hose and start the car from a cold start, you should feel a big rush of air come through that hose.

The only other component is the mass air sensor on the filter housing at the other end of the big hose/air pump. If the filter's clean and everything else checks out, that's likely your problem. INPA can tell you for sure - just activate the air pump test and you should observe airflow on the sensor reading. That was the problem we had on our '05 - the sensor wasn't reading any flow. Replaced it and all good on that code since then.

[kevinkay]

THANKS!
I will be blowing it tomorrow......

My error code is P1093, bank 2 - too rich

[e39_touring]

Oh, I don't think your problem will be with the air injection system then. The code I was getting had to do with a faulty secondary mass air sensor.

That air pump system described above just pumps fresh air into the exhaust for x number of seconds on startup to help light off the cats. After it shuts off, it doesn't come into play anymore until the next cold start.

Bank 2 too rich could be a lot of other things from bad o2 sensor, leaky injectors, bad plugs or coils, etc.

[kevinkay]

Thanks touring!
Working on solving this code for a year, I am getting desperate -

all new O2 sensors (rears twice)
swapped injectors/coils/plugs between banks - error didn't change bank
new fuel filter (pressure regulator)
New MAF
no intake leaks, new rubber boot into throttle body
new DISA O ring
new Idle control valve
new valve cover gasket
New gas cap
New gaskets/bolts between exhaust manifold and first section of tailpipe

[upallnight]

Hey Kevin, did you ever fix the pressure leak down of the fuel system after you shut the engine off? If not I would cycle the key on and off several times but don't start the engine, and pull the three spark plugs in bank 2 to see if any are wet.

[andrewwynn]

I see where your thought is but he said he swapped injectors and that should have moved the fault to the other bank.

You do need to make sure the pressure holds power off. I would check the plugs for weeping injectors nonetheless. Maybe multiple injectors leaking and swapping them didn't isolate to one bank. I would do as suggested to keep fuel rail pressurised for an hour or two (turn key to on to charge fuel rail) then off, do that every 30 minutes for an hour (3 times) wait another 30 minutes and at 90 minutes pull all the plugs and look for wet plugs indicating injectors not closing completely.

If so, injector cleaner may clear the problem.


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[kevinkay]

THANKS.
trying to work on one issue at a time but they all can be related.
My rail does NOT hold pressure, within 5 min its almost down to zero with eng. not running. Engine running pressure holds where it should. I changed fuel filter twice and new fuel pump to correct this. I also had the fuel rail/injectors sitting on a towel turning pump on, on/off, let sit and never saw a drop of gas. My car starts perfect on a cold start, prefect on a hot start, but stumbles to start on a warm (sitting an hour after a long run) start. I have changed the duel temp sensor and the temp sensor at the radiator with no change.
My motto - some guys play golf, I play mechanic!

THANKS for all the input.

[andrewwynn]

How long injectors sitting on the towel? You said pressure drops after 5 minutes means you would have to cycle fuel pump on at least every five minutes to keep pressure up.

Fuel rail leaks pressure after replacing FPR and fuel pump? That leads to indicate a faulty new part if injectors aren't leaking (unless you have a leak to the world: no gas smell?)


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