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-   -   Secondary Air Injection removal (http://forum.e46fanatics.com/showthread.php?t=599080)

F1004fun 08-10-2008 08:01 PM

Secondary Air Injection removal
 
I know it seems kinda meaningless but how simple would it be to remove the secondary air injection pump and valve, make a block-off plate and wire up a simple circuit that produces .100V for the pre-cat 02 sensors upon pump activation to make it look like thing is working. I already have the plate on and I have a DPDT relay all wired up but I dont know how to make a ciruit that uses a good regulated 5volts and steps it down to .100v, got any ideas?

PEI330Ci 08-10-2008 10:10 PM

Quote:

Originally Posted by F1004fun (Post 8360601)
I know it seems kinda meaningless but how simple would it be to remove the secondary air injection pump and valve, make a block-off plate and wire up a simple circuit that produces .100V for the pre-cat 02 sensors upon pump activation to make it look like thing is working. I already have the plate on and I have a DPDT relay all wired up but I dont know how to make a ciruit that uses a good regulated 5volts and steps it down to .100v, got any ideas?

Why would you take it off in the first place?

F1004fun 08-10-2008 11:26 PM

I don't know, I'm wierd like that. It's heavy, useless, and I can see me headers better with it out of the way. But it's really easy to bypass with a $7 dollar relay, just cant figure out how to make a steady .100V out of a 5V reference voltage supply. Know any smart electrical engineers?

PEI330Ci 08-11-2008 08:42 AM

Quote:

Originally Posted by F1004fun (Post 8361498)
I don't know, I'm wierd like that. It's heavy, useless, and I can see me headers better with it out of the way. But it's really easy to bypass with a $7 dollar relay, just cant figure out how to make a steady .100V out of a 5V reference voltage supply. Know any smart electrical engineers?

- It's actually pretty light
- You will fail your smog test without it
- A relay has nothing to do with removing this piece

If you are dead set on removing this piece, just remove it. There's nothing more to it than unplugging the connector and unbolting the mounting bracket from the strut tower. When you go to get your yearly smog test done, re-install it before hand and have your error codes read and cleared on the DME.

F1004fun 08-11-2008 02:21 PM

7lbs is 7lbs less that I gotta haul around no matter how you look at it, and its nose weight if you really want to split hairs.
I wont fail smog if I can generate the voltage I need. The smog guys don't know what the heck isn't there any more.
And the relay is the key, when the secondary air ground signal is sent from the DME it triggers the relay for the pump. Well I used that ground to energize a DPDT relay that interupts the front 02 sensor signal line with a voltage signal of my own, the DME doesn't look for a voltage swing that early on startup just a solid lean signal to show enough airflow from the pump. I have it close but just not there yet.
Not a big debater, just wanted some help with generating the voltage signal I need.

TxZHP04 08-11-2008 10:07 PM

Quote:

Originally Posted by F1004fun (Post 8364002)
7lbs is 7lbs less that I gotta haul around no matter how you look at it, and its nose weight if you really want to split hairs.

You picked an interesting member to debate weight removal with.... :rofl:

PEI330Ci 08-12-2008 06:31 AM

Quote:

Originally Posted by F1004fun (Post 8364002)
when the secondary air ground signal is sent from the DME it triggers the relay for the pump. Well I used that ground to energize a DPDT relay that interupts the front 02 sensor signal line with a voltage signal of my own

I'll explain what I'm getting at in greater detail:

On cold startup, the engine needs more fuel to run smoothly. The air injection pump adds air after the combustion process to an exhaust mixure that is still fuel rich. This allows the cats to more effectively burn off excess fuel. The volume of air added is actualy in excess of what is required for a stoich burn, the result is a higher burn tempurature in the cats. The purpose of this is to bring the cats up to proper operating temperature sooner.

The DME looks at the post cat sensors at a certain point in the warmup sequence, and if the signal doesn't match what it's expecting, it will trigger a code. The front, or pre-cat sensors have nothing to do with this. They are expected to be "off" until the warmup sequence is complete. Using a dual pole/dual throw relay is a bad idea.

Quote:

Originally Posted by TxZHP04 (Post 8366448)
You picked an interesting member to debate weight removal with.... :rofl:

What the heck do I know? :craig:

paraklas 08-12-2008 07:19 AM

Euro spec cars don't have the secondary air injection thing. So isn't possible to have it removed and reprogram the ECU with software from Europe? You will not need relays or whatever you think you need and no error codes as well.

PEI330Ci 08-12-2008 07:58 AM

Quote:

Originally Posted by paraklas (Post 8367669)
Euro spec cars don't have the secondary air injection thing. So isn't possible to have it removed and reprogram the ECU with software from Europe? You will not need relays or whatever you think you need and no error codes as well.

http://www.realoem.com/bmw/showparts...88&hg=11&fg=50

Yes they do.

paraklas 08-12-2008 08:38 AM

Not all of them then. ;)
http://www.argyrides.eu/bmw/performa...e/DSCF2227.JPG

F1004fun 08-12-2008 02:26 PM

I like the Euro software idea but I haven't found anybody that can flash the DME for just secondary air removal. This would work at least in CA, because you only need like 5 outta 7 or monitors to be concluded to pass, so if all the others were good it should fly.
And to pie33oci, I hate to be an rude but you might want to check on that statement. The DME looks at pre-cat sensors for the lean signal upon secondary air injection, I know this because I have had my rear 02's disconnected for months and only throws no-signal faults, the day I took the secondary air off I got insuficient airflow faults, put the pump back on and no more faults, I think it even says in the GT1 that the DME looks at pre-cat sensors to test the flow out of the pump. Both front and rear sensors are the same with the same heater circuit, they both get up to temp and swinging voltage in about 15-20 seconds upon startup, even a cold start, the front 02's just a little faster. You sound like a smart guy and I'm not trying to knock it, I can hold my own to though.
Back to my original question, anybody know any electrical engineers that can make a little circuit? I'll pay em, give em beer, whatever.

TxZHP04 08-12-2008 02:57 PM

Secondary air operation described starting around p37:

http://www.bmwmotorsports.org/BMW_docs/m54x5.pdf

The context is X5 but the motor is still M54.

PEI330Ci 08-12-2008 05:36 PM

Quote:

Originally Posted by F1004fun (Post 8369317)
I like the Euro software idea but I haven't found anybody that can flash the DME for just secondary air removal. This would work at least in CA, because you only need like 5 outta 7 or monitors to be concluded to pass, so if all the others were good it should fly.
And to pie33oci, I hate to be an rude but you might want to check on that statement. The DME looks at pre-cat sensors for the lean signal upon secondary air injection, I know this because I have had my rear 02's disconnected for months and only throws no-signal faults, the day I took the secondary air off I got insuficient airflow faults, put the pump back on and no more faults, I think it even says in the GT1 that the DME looks at pre-cat sensors to test the flow out of the pump. Both front and rear sensors are the same with the same heater circuit, they both get up to temp and swinging voltage in about 15-20 seconds upon startup, even a cold start, the front 02's just a little faster. You sound like a smart guy and I'm not trying to knock it, I can hold my own to though.
Back to my original question, anybody know any electrical engineers that can make a little circuit? I'll pay em, give em beer, whatever.

I play with this stuff pretty extensively, however I'm sometimes mistaken on some details. This is one of them. A while ago I had to monitor the O2 sensor signals to trouble shoot some fault codes....the air injection pump was connected so I didn't have any issues with it. I understand what you are trying to do, but unfortunately I haven't heard of anyone succesfully simulating an O2 sensor output that the DME will accept. It seems to want to see the voltage fluctuations...

One option would be to try installing a pair of Innovate LC-1s as the pre-cat source, then program the voltage output thresholds to what the DME is looking for.

Another option is to wait for Shark Edit to arrive...

Quote:

Originally Posted by TxZHP04 (Post 8369498)
Secondary air operation described starting around p37:

http://www.bmwmotorsports.org/BMW_docs/m54x5.pdf

The context is X5 but the motor is still M54.

I've had that for a few years, good reference. There's also a Z4 based M54 doc, and M54 introduction doc floating around.

kpeng 08-15-2008 10:13 PM

It's completely pointless to remove it. It weighs nothing, and will throw a CEL. Need any more reason to not waste your time?

F1004fun 08-16-2008 10:34 AM

Hey, thanx for the advice on the Innovate LC-1, I didn't know about this cool little gizmo. I dont know if it will work for this, but I ordered one to try and turn off the CEL for not have cats at this moment, plus it gives me a wideband output I can use to plug into when I tune my car. One of our customers is electronics guru and helped me out with a circuit, he called it a volage comparater something. It basicaly uses one of the 5v sensor supply voltage wires and steps it down with a couple of resistors, it actually doesn't look all that bad. I'll let you know if it works.

paraklas 08-17-2008 04:02 AM

Voltage regulator you mean? Whatever input it will provide a steady output

gutguy1 08-17-2008 07:57 AM

secondary air pump
 
Is it difficult to replace the secondary air pump valve that is on the exhaust manifold?

gutguy1 08-17-2008 08:01 AM

I have been told that my secondary air pump system has caused the cel light to be on. I disconnected the outlet air hose from the secondary air pump and it blows adequate amounts of air when it is running (cold start). Does this mean that the problem is likely the secondary air pump valve is not functioning and needs to be replaced? The dealer wants to replace the whole system and charge large alot. Is replacement of the valve very difficult?

F1004fun 08-27-2008 07:01 PM

Hey dude, well it's good that your pump works. Most of the time I see the vacuum hose that comes of the back side of the valve is all rotted and leaking vacuum, if you have a vacuum gauge then put that on when you start your car up cold in the morning. I really hope that is just a broken hose, if you have vacuum signal and your pump is working then you might have clogged secondary air ports in the head, that would suck.
And to answer your question, the valve is easy to replace, two 10mm nuts and thats it. If you happen to have a vacuum pump then you could also pull vacuum on the valve to check for a blown diaphram.

F1004fun 09-12-2008 02:18 PM

Well it worked, Using the Innovate LC-1 and a DPDT relay I have no secondary air injection and no CEL, monitors have checked out and passed the sencondary air system. I still have the light coming on for not having catalytic convertors but I am close to keeping that off as well using the other channel on the LC-1. Thanks to pei330ci for the input, and kpeng I guess it's not a total waste of time huh?


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