Louie: PM sent from me.

If you snip the green wire on the stock OEM harness be aware that it is a shielded wire. Be certain you do not somehow short the shield to the center conductor. I had a car where someone had tried to fix this wire and they soldered the shield to the center O2 signal line. It took over 2 days to figure this out and it totally screwed up the mixture since it tricked the DME into thinking the mixture was always lean and the end result was the DME trying to richen the mixture! What a pain to figure out this over rich condition!

I don't agree with this statement? You can solder if done properly. Also consider that within the DME the O2 sensor signal travels through several (10+) soldered connections without any issue, adding just one more will not change things. A soldered connection will be better than a mechanically connected terminal.

I agree with Sal, if you look closely at the end connector it's actually soldered.

Very nice job on this part. IMHO: I would simply wire this new part by:
1- cutting the stock OEM green wire.
2- Remove and discard the old connector.
3- Cut back the shield about 1/2" and shrink tube it.
4- Solder a round spade to the center black 'O2 Signal' line within the green wire.
5- Attach to new plug.

Once again nice job.

Thank yiu Dr Sal SmileWavy, I still love my BMW/Buick metal injectors SmileWavy take care, Jim

oxygen sensor
 

louie, i need one of those, i have a current thread running 3.2 won't start. One of the issues is a broke O sensor. you can send me your info to [ i'll send paypal or check
thanks
mark

My son installed this piece on his 85 Carrera. Easy install and problems with running SOLVED.

We just got it to run by pulling an injector plug and manually grounding it. It's definaty electrical

PM him. I don't think he's on here as often as some of us are!

Thanks Louie got back to me could you remove my email as i can't edit it
Thanks
mark

Done.

installing
 

Louis, i too seem dumb as a rock. It looks like the pictures puts yours in series with the old one. My old one is severed. the car is in the upholstry shop right now so I haven't been able to compare pictures on this thread to it yet.
mark

Mark,

You just need the most inner wire, the other is just shielding. Here's some information from Sal. Hope this help.

Originally Posted by scarceller View Post
Very nice job on this part. IMHO: I would simply wire this new part by:
1- cutting the stock OEM green wire.
2- Remove and discard the old connector.
3- Cut back the shield about 1/2" and shrink tube it.
4- Solder a round spade to the center black 'O2 Signal' line within the green wire.
5- Attach to new plug.

Once again nice job.

Hi louise
Do you still have extra piece that I can buy from you? If yes then How much and How do I send you the payment?
Thanks

+1 for Don - for the first part of his statement.

To be precise, the sensor needs a reference oxygen source, and the electrode is internally open to atmosphere on one side so it can obtain it. This oxygen actually travels down the braided copper connector wire.

See p14:

http://wbo2.com/lsu/oxygen13-17.pdf

It certainly doesn't need much oxygen - but that's why anything that prevents or restricts free flow of oxygen along the wire to the sensor - like soldering and/or heatshrinking the connectors, or blobbing silicon on them for "weatherproofing" - is really not a spiffy idea.

Bosch oxygen sensor installation document specifically states (second bolded bullet point on the first page) :

http://www.boschautoparts.com/BAP_Technical_Resources%2fOxygen%20Sensors%2fO2Ins tallGDWEB09.pdf


This part has been around since Bosch invented it in 1982. Still amazed this isn't common knowledge.

I read the above documents. There are a number of reasons not to solder automotive wires in certain applications. If you look at their universal O2 sensor kit, they cut the wires and splice on the OE connector with Posi-lock connectors. These are very nice connectors.
Do you guys really think the O2 sensor sucks air in along the length of the wire for its reference material (like Fernando Valenzuela breathing through his eyes?) ? I think the air is exposed to the reference electrode at the sensor itself. I also think the solder comment is because soldering fine wires causes a fatigue issue which can lead to breakage when exposed to vibration. Posi-lock tolerate this much better. That's why they talk about early failure in the above document, not malfunction or inaccuracy.
Anyway, that's how I understood it, and I may be completely wrong.
Good luck,
Dave

Yeh, I noticed that. I found Posi-lock completely by accident at a FLAPS about 8 years ago and used them for a stereo install. They really are very good, and I've been using them ever since.

Nice to see Bosch seem to have the same opinion.

I can't speak for anyone else, but I do.

Do a search on this forum (especially the 944 side) for FR Wilks. Don't know if he's posted recently, but used to be fairly active when I ran a 944 - long time ago now.

Then read his website, and see if you think he knows what he's talking about. (guy has re-engineered and sells PROMs for the 944 Motronic, both for more power and the "shudder fix" that afflicts some ageing 944's - he owns several of these, heh).

His website probably contains the most information freely available on the web for the Bosche Motronics and associated sensors. But it's 944-centric, although much of the information is applicable to other brands/models, naturally.

Based on his instructions, I socketed a buddy's Series 1 944 (24 pin) Motoronic to 28 pin so we could use the Wilks shudder-fix PROM. Worked a treat, issue solved never to return (buddy was then sorry he'd not opted for the PowerPROM, but that's another story, heh).

In my opinion, it's pretty obvious Mr. Wilks has been involved in embedded microcontroller applications for many years and knows his way around ICE's and disassemblers, as well as early automotive engine management systems.

He says on his website, (copyright date of 1999) Oxygen Sensor - Lambda, right under the table of Bosch replacement part #'s:

Seems pretty convincing to me. :)

OK. I stand corrected. I guess I was thinking aobut the older O2 sensors before special lambda wire was used.
Thanks for the information.
Dave

Will this fit an 82 SC?

If it has the same connector as the 3.2 84-85

Louie - Sending you PM as well but I could use 2. Can pick up since I'm in the SF area as well. Thanks!

resurrecting this, just PMed Louie.

hoping he is still making these. trying to remove O2 to pull the engine tin for valve adjust.

desperate.....
http://forums.pelicanparts.com/uploa...1483025781.jpg
http://forums.pelicanparts.com/uploa...1483025824.jpg

I am sure he does.

yep, got a PM back that he is making some more. just read through this to confirm I can cut back the shielding and just crimp the connector to the internal wire.

now to be patient for Louie85 to get it to me.

My connector is also not looking good. I have a PM into Louie85 about the connector.

http://forums.pelicanparts.com/uploa...1510411931.jpg

Another pic, can’t tell if the wire is damaged or not

http://forums.pelicanparts.com/uploa...1510420747.jpg

I'm in the same boat and wondering if it works for a 1980 SC. I'll PM Louie.

This has actually been covered on this forum before...

Bosch (who actually invented the automotive oxygen sensor), needed a source of reference air for the oxygen ion pump in order that the zirconium dioxide cell had something to compare against the exhaust gas... (yeh, these things are a solid-state electrochemical fuel cell, pretty amazing for the 60's).

A Bosch sensor is 100% sealed - absolutely airtight, by design. They don't take reference air via the sensor body - because road dirt buildup on the sensor could block the air path without which the sensor can't/doesn't work.

The source for the reference air is instead down the the stranded wire in the harness. It only needs a minute amount.

If you solder the connectors, or decide the harness would look nicer with heat shrink over it, you cut off the path for the reference air.

Which is why Bosch sensors come with a pre-attached harness, and why multiple application notes over the years have explicitly stated not to solder the connectors.

If you look at the picture for the universal replacement sensor on Bosch's web site https://www.boschautoparts.com/en/auto/oxygen-sensors/premium-oxygen-sensors-with-oe-smartlink, you may note the provided Posi-Lock (crush-type solderless) connectors...

e.g. from p30 of http://aa-bosch-ecat-ap.resource.bosch.com/sao_ecat/downloads/Bosch%20Australia%20Oxygen%20Sensor%20Catalogue%20 2013.pdf:

It's probably also worth pointing out that a single-wire O2 sensor also relies on a good electrical ground via the sensor body where it screws into the bung to complete the circuit. And by extension, through the headers to the earth strap.

I'm a little bemused why the topic of extending the life of these sensors keeps coming up. They're wear items like spark plugs and filters. Many things can hurt them - like thermal or mechanical shock, leaded fuel etc.

The folks who designed/make them say They're pretty easy to check with an oscilloscope - but If you have a system that relies on an accurate lambda signal - i.e. for closed loop operation - then you need a good sensor, otherwise the motor won't run as designed.

Any more of these available?

I'd like to purchase one of these.

Thanks,

JF

PMed to order a couple.

I have same problem, anyone know if these are still available? PM'd Louie but havent heard back yet. My plug is hanging on by a bare wire.

Here is where I got mine if you need another option.


https://www.kroonwireharnesses.com/index.php?route=product/product&product_id=747&search=O2+


Sent from my iPhone using Tapatalk

Great - thankyou - I am looking into it, so far their shipping quote is for 80 Euros!

They have a cheaper option. Email them.

Looks like a common problem...guess I’ll be machining up a new one.
http://forums.pelicanparts.com/uploa...1608891689.jpg

After reading this old thread, I’m beginning to wonder whether my DIY fix of this connector last year (solder + heat shrink) is the cause of my idle problems. PMed Louie to see if he has any more connectors, but haven’t heard back yet. Has anyone come across a cost effective replacement connector? Thanks.

From what I learned back when I bought one of the replacements, that connector is common to BMW, VW, Mercedes, and of course Porsche of the same era. If you have a good parts guy from other German makers they sell the same connector to the harness. They all break after 30+ years if the car is driven much at all. They plastic yellows and get brittle.

Just like the flywheel sensors for a BMW work perfect on our 911s, that O2 sensor connector is the same part, just finding the source is the hard part.

If you fix this connector you MUST be aware that the wire is a shielded line. It has a center conductor that's the actual signal wire. But it also has a outer braided shield wire, if you accidentally happen to solder the shield to the conductor or they touch in any manner then what this does is grounds the signal line. If the signal line gets grounded it drives the signal to 0vdc this causes the DME to see and think that the mixture is lean and all hell breaks loose! The DME thinks the O2 sensor is sending a lean signal and the DME now starts to richen mixture and it will go super rich!

Be very careful fixing this O2 signal connector.