Secondary Air Injection Veterans needed

[Vidyashankara]

Hey guys, Sorry to bring up this old post.

I have the same problem with the SAI system. Both P1410 and 1411 codes are on. The OEM check valve and change over valves are expensive.

Particlewave, I know you confirmed the Mercedes MTC3095 was a perfect fit for the check value in 986. Can you confirm if the mercedes part for the change over value is also a good fit? The part looks different. How did you make it fit? Do you have pictures you can share?
NEW MERCEDES AIR VALVE 380SLC 380SEL 380SL 380SEC 420SEL 190E OE # 000-140-77-60 | eBay


Also, any update on your little hack on fooling the DME during cold starts? do you have it up and running?

[Boxstard]

Originally Posted by Vidyashankara

Hey guys, Sorry to bring up this old post.

I have the same problem with the SAI system. Both P1410 and 1411 codes are on. The OEM check valve and change over valves are expensive.

Particlewave, I know you confirmed the Mercedes MTC3095 was a perfect fit for the check value in 986. Can you confirm if the mercedes part for the change over value is also a good fit? The part looks different. How did you make it fit? Do you have pictures you can share?
NEW MERCEDES AIR VALVE 380SLC 380SEL 380SL 380SEC 420SEL 190E OE # 000-140-77-60 | eBay


Also, any update on your little hack on fooling the DME during cold starts? do you have it up and running?

I fixed my SAI last winter, not knowning cheaper MB parts... That changeover valve should work, only the difference is the 90-deg orientation of small nipple but you will be fine with enough length silicone hose.

Did you check if the vacuum reservoir is holding vacuum and the solenoid switch is functioning to apply vacuum to the changeover valve?

This winter I noticed that my SAI motor was running erratically and got CEL... but it was just a fuse on its last leg... New fuse was all it took.

Good luck!

[Vidyashankara]

Originally Posted by Boxstard

I fixed my SAI last winter, not knowning cheaper MB parts... That changeover valve should work, only the difference is the 90-deg orientation of small nipple but you will be fine with enough length silicone hose.

Did you check if the vacuum reservoir is holding vacuum and the solenoid switch is functioning to apply vacuum to the changeover valve?

This winter I noticed that my SAI motor was running erratically and got CEL... but it was just a fuse on its last leg... New fuse was all it took.

Good luck!

Hey! I havent diagnosed any of the parts as yet. Just that I get P0410 and P1411. Once the weather gets warmer, I will start pulling things around and seeing what needs to be replaced. The pump starts up and turns off after a couple of mins, so that should be good.

[boxfix]

Originally Posted by Boxstard

I fixed my SAI last winter, not knowning cheaper MB parts... That changeover valve should work, only the difference is the 90-deg orientation of small nipple but you will be fine with enough length silicone hose.

Did you check if the vacuum reservoir is holding vacuum and the solenoid switch is functioning to apply vacuum to the changeover valve?

This winter I noticed that my SAI motor was running erratically and got CEL... but it was just a fuse on its last leg... New fuse was all it took.

Good luck!

I had a bad vacuum reservoir they are only 20.00 or so. easy to test with a hand vacuum pump. They make these in 2 pieces and glue it together. It should be roto molded. You can buy metal ones from Summit Racing.

The solenoid valves are the same in many German cars.

[Gelbster]

As Mr.Particle mentioned, a 90 degree elbow for the vacuum line would reorient the fitting.

[thom4782]

CA now requires a visual inspection along with the test machine. Last summer I couldn't find one, who wouldn't look. So if they find all the SAI junk missing, it could be a problem.

[Gelbster]

Originally Posted by thom4782

CA now requires a visual inspection along with the test machine. Last summer I couldn't find one, who wouldn't look. So if they find all the SAI junk missing, it could be a problem.

The Visual Test is one of the few advantages we have with the Boxster & Smog Tests. Access is so awful ! The Tech is very unlikely to remove the engine cover. If you think this is a risk, just leave the SAI components in place.Really , a Smog Tech is not allowed to unbolt anything on your car. The Referee is a different story.
The DAD system is so effective at finding tampering that the Techs I know don't make much effort with Visuals. The DAD is far more effective because it compares the stock ECU program to your actual. And DAD keep loading more & more data into their system.They are more focused on newer, higher volume cars and known tampering targets (Ricers !,Mustangs,big Mopars,trucks) ,so we may get away with being overlooked ?

[particlewave]

So...barely 3 months on and the CEL came back. Same P0410 and P1411.
To be fair, I only drove the car 4 or 5 times in that period. The good news is that my change over valve is still doing just fine. The bad news is that I had to dig deeper into the SAI.

I tested vacuum before and after the electronic change over valve and got 16" of water on both sides...vacuum good, electronic change over valve good.
Used the Durametric to activate the air pump and electronic change over valve at idle with the change over valve disconnected from the line that goes to the check valve. Good airflow.
Crap. I have to remove the alternator and pull the check valve.

Well, I did. It was a bit rough. The top half of the upper fitting had completely deteriorated and the bits of rust scale and left over fitting were plugging the valve.
The dents and scrapes are from me beating the crap out of it.



A new OEM valve ranges from $80-$150. Seriously?
It's a bit of stamped sheet metal and a diaphragm.

Nippondenso 99311325003 Porsche SAI check valve ~$100+:



I ran a google image search and found one that looks the same, right down to the little nubs on the side.
Guess what? It's s $20 1993 Mercedes 300e part. Same as the change over valve. Imagine that.

MTC 3095 Mercedes SAI check valve ~$20:



I ordered one and will report back next week when it arrives, but I'm 95% sure that is exactly the same as the "Porsche" part.

[Stroked & Blown]

The ROW flash is looking like a much better option. Cheaper, simpler, and adds lightness.

[Gelbster]

Originally Posted by Stroked & Blown

The ROW flash is looking like a much better option. Cheaper, simpler, and adds lightness.

There is a far more compelling case than that for some of us. We can not fix the SAI system. Some very competent Forum members have performed every imaginable test yet fail to find a fault. If you can't find the fault, you can't eliminate the SAI fault codes .If the SAI fault code is present, you can't pass the Smog test so you can't get a registration sticker. If you run out of time on your old sticker you are in real trouble.
Ultimately there is no alternative to the ROW flash until someone figures out a reliable way to fix the SAI system.
Sometimes it is easy to fix the SAI but not always !

[particlewave]

If the problem comes up again after replacing the check valve, I'm just going to remove the whole system.

I've just built a circuit that fools the DME during cold starts, so no ROW flash needed. The circuit is triggered by the air pump relay and just feeds a signal to the DME indicating that the required emission conditions have been met.
That will be the end of it and no pricey flash.

[Xpit77]

My 99 had the same problem. My indie determined it was the valve. I remember getting a deal on one online. I also remember it was a SOB to get at.Every so often it will throw those two codes. I clear them and gone.

[Gelbster]

Originally Posted by particlewave

If the problem comes up again after replacing the check valve, I'm just going to remove the whole system.

I've just built a circuit that fools the DME during cold starts, so no ROW flash needed. The circuit is triggered by the air pump relay and just feeds a signal to the DME indicating that the required emission conditions have been met.
That will be the end of it and no pricey flash.

Mr. Particleweave,
I agree about the ROW reflash cost for an SAI solution. The ROW reflash includes several other features(see ECU Doctors for details) but they are not useful to me. I just want to pass Smog so I can be 'legal' and get a sticker.
Your brilliant wiring modification seems excellent .One advantage is that since it is triggered by an existing relay ,it is easily reversible if some new Smog Law detects the hack.
If you would like a guinea pig to volunteer to use your modification and report back - please PM me .

[Stroked & Blown]

Particle wave - I am interested in buying something like this if you produce it.

[particlewave]

Originally Posted by Gelbster

Mr. Particleweave,
I agree about the ROW reflash cost for an SAI solution. The ROW reflash includes several other features(see ECU Doctors for details) but they are not useful to me. I just want to pass Smog so I can be 'legal' and get a sticker.
Your brilliant wiring modification seems excellent .One advantage is that since it is triggered by an existing relay ,it is easily reversible if some new Smog Law detects the hack.
If you would like a guinea pig to volunteer to use your modification and report back - please PM me .

Originally Posted by Stroked & Blown

Particle wave - I am interested in buying something like this if you produce it.

I'm going to go ahead and order the components to make 5-10, but I want to run this one on my car for a good 3-4 weeks to give it a good shakedown and address any bugs that might pop up. I'll try to drive everyday so it cycles the SAI as much as possible and monitor emissions components on the Durametric.

If everything looks good, we can go from there. Sound good?

I don't foresee any issues at all and I would think even California guys could get away with it as the system should show ready and the only time emissions would be high is at cold start. If you drive your car to the emissions check, it shouldn't trigger the SAI when they test it, but that depends on how long it sits before they get to it.

[mrmoto444]

@particlewave,

I'm going through the SAI torture process and would love to hear more about your kit to present the "ready" signals. If you could, please send me more information on that kit. I you don't have the kit, I'd be happy to assemble or replicate what I'm guessing is an electronic assembly to present differing signals to the ECU.

Being a total newbie on this forum, I don' think I have privileges to DM you. I hope you catch the reply to this thread. And, thanks for the work you've put into your forum contributions, and kits to date :-)

Hmm... In case you're skeptical about a guy from CA asking for a... "closed-course competition use only, not for highway use" modification, feel free to see some of my other posts from the usual 2-wheel forum I used to hang out on...

https://advrider.com/f/members/mrmoto.6725/

- Scott

Originally Posted by particlewave

I'm going to go ahead and order the components to make 5-10, but I want to run this one on my car for a good 3-4 weeks to give it a good shakedown and address any bugs that might pop up. I'll try to drive everyday so it cycles the SAI as much as possible and monitor emissions components on the Durametric.

If everything looks good, we can go from there. Sound good?

I don't foresee any issues at all and I would think even California guys could get away with it as the system should show ready and the only time emissions would be high is at cold start. If you drive your car to the emissions check, it shouldn't trigger the SAI when they test it, but that depends on how long it sits before they get to it.

[Stroked & Blown]

Sounds great!

[Gelbster]

"I would think even California guys could get away with it as the system should show ready "
To overcome the problem of the Visual Inspection done by the Test-Only Smog Stations - just leave the SAI Pump in place but non-functional.
I have a particularly rigorous Test Only appointment soon so will report back on how determined they are to actually do a Visual Inspection on a stock Boxster.

[particlewave]

Just a follow up on the MTC 3095: I received it yesterday and can confirm that it is the exact same valve as the Porsche part.

[Gelbster]

Thanks for closing that loop - great parts sleuthing - a valuable alternative to save other Forum members some $ and grief !
How goes your related SAI test project ?
I confess a personal interest because I have no DTC's but can't get the Secondary Air system to show Readiness