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I posted last week asking if it was true that the Regina system used a completely different type of O2 sensor than the Bosch systems. The replies were that, yes, Regina uses a "titania" sensor and the generics will not work.
I called FCP Groton since their site lists a generic walker for ALL 740s including the Regina years. They assured me that their $49 Walker generic works with Regina.
Frankly, I don't know who to believe, so I'm hoping for some more input. If Groton is right, I want to save a lot of money. If they are wrong, then I'm sure they will change their listing if I can convince them.
Andy in St. Paul
'91 745 Regina 186K, '89 244 136K, '87 245 lost the rust battle at 225K
Regina is a nice ride, but she ain't a cheap date.
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Andy '91 745 184K, '89 244 135K, '87 245 lost the rust battle at 225K mi
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Since in essence only the electrical interface is different, but the sensor measures the same thing, it should be possible to make a cheap interface circuit to interface the voltage-output sensor to the resistance-sensing input of the ECU.
I'm in a bad shape now as I've already bought the "universal" $49 O2 sensor and it's patiently waiting on the shelf.
What I'm probably going to do is to pull it out of the car (the one that I have seems to be still working, although it's lagging), connect it to a power supply to heat it up, and measure its resistance while spraying some CO2 from a can around it. If it works the resistance should change. And there should be no voltage output from it at all -- that so far seems the case, as when I disconnected the sensor from the ECU it read a steady 0.00V. So it may be just true that it's a resistance-output sensor in Regina.
Alas, there's a rather trivial op-amp based circuit to change voltage into "virtual resistance". I will investigate and post my findings with some photo documentation. I also have (the long overdue) LED-overhaul of $7 instrument backlight bulbs docs waiting to be finished.
At last something a (sudo) electrical-engineer would be happy with :)
At least it's less messy once you get the original sensor out to play with.
Cheers, Kuba
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Kuba,
As an alternative to testing with CO2 gas, check this guy's "Workbench Test" in this web page for ease. I can vouch for the method personally, and add the response time is even better than quoted using a mapp gas flame. 'Course I was horsing around with Zirconia (Bosch) heated sensors, one three wire and one four wire. Good thing to try with that universal you've got moldering on the shelf to get a baseline for a virgin part.
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Art Benstein near Baltimore
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This discussion continued on my earlier post so look down a ways if this thread interests you.
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Andy '91 745 184K, '89 244 135K, '87 245 lost the rust battle at 225K mi
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I emailed him. Will let you know.
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Andy '91 745 184K, '89 244 135K, '87 245 lost the rust battle at 225K mi
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Contact Rusty at www.rprusa.com for advice. www.ipdusa.com is also very good.
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I got a response from Rusty at rprusa.com.
"Andy; hello. My experience has been to only use original equipment
starting in 1989 to avoid problems with the engine management.
Thank you, Rusty"
I don't think this really sheds any light on the subject.
I have done as also suggested and Googled volvo and titania, and though I find sites that talk about O2 sensors and the difference between titania and zirconia, the one's that list the makes using titania do NOT include Volvo.
While I don't want to doubt the guys that said that Regina is titania, but so far I haven't seen anything to back that up. Someone must have some documentation one way or the other. Can anyone convince me before I buy the $40 Bosch sensor for Ford and cut and splice it in to find out for myself ?
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Andy '91 745 184K, '89 244 135K, '87 245 lost the rust battle at 225K mi
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I haven't found a definitive "Regina = Titania" source either. But there was a Regina post a few months ago where the guy (whitefox?) tried a Bosch, then posted back to say it did not work.
And what titania prices I've seen are in the $200 range or more. My gut feel is that FCP just doesn't understand the difference. Based on that earlier post, I don't plan to experiment.
I just found the whitefox post (the last of 4), as follows...
>>>>>>>>>>>>>>>
02 Sensor Experiments 900 1994
posted by someone claiming to be WhiteFox on Sat Sep 6 19:28 EST 2003
Well, I hooked up an oscilloscope to the O2 sensor line today and found that at idle, the voltage stayed near 0 volts indefinitely. That accounts for the setting of the code. As soon as the engine is revved in neutral, the voltage rises to around 1 volt, but slowly drifts down to 0 again.
No quick alternating between 0 and 1 volt as the voltmeter suggested. Obviously, the Bosch universal 3 wire sensor does not work in this system. New Volvo part due to arrive soon, so will report on results after installing it.
-WF
>>>>>>>>>>>>>>>>>>>>>>
Search RWD for whitefox to see the whole thread. BY
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Bruce Young,
'93 940-NA (current) 240s (one V8) 140s 122s since '63.
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What WhiteFox saw does not convict the sensor. The whole system has to be correct to see the waveform he was expecting that indicates a closed loop.
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Art Benstein near Baltimore
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Here's another (British) seller specializing in Oxygen sensors that lists the same one for both systems.
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Andy '91 745 184K, '89 244 134K, '87 245 lost the rust battle at 225K mi
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http://www.lambdasensor.com/main/volvo.htm
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Andy '91 745 184K, '89 244 134K, '87 245 lost the rust battle at 225K mi
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Andy,
That JL site looked promising at first, but all their "Original Equip." numbers are Bosch, not Vehicle numbers as I'd hoped. FWIW, the Volvo 3-wire sensor numbers are:
Regina 3517394-7
Bosch 3501753-2
Here is what I found there:
JustLambda's Titania 3-wire universal 11014T18 (using JL x-ref, under NTK) crosses to NTKD5F, and JL's own:
11126 VW
11127 VW
11128 Citroen
And the price listed is for 11011T18 is = to $141.65 at today's rate!
Going to JL's All Parts listing, those three JL numbers above are shown as 3-wire Titanias, BUT there are No Volvos anywhere on that "All Parts" list.
I'm afraid that nothing on the JL site suggests that a true Zirc/Titania "Universal" sensor exists.
And here's another bit I pulled from an NTK tech paper:
"At this point, the person selecting the correct oxygen sensor replacement must be reminded that should a vehicle be using the circuitry in the ECU/ECM for atitania oxygen sensor, care must be taken that the ... zirconia sensor, is NOT accidentally installed in the vehicle. Obviously, these two are definitely NOT interchangeable! "
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Bruce Young,
'93 940-NA (current) 240s (one V8) 140s 122s since '63.
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Thanks Bruce,
Your analysis is useful and more than I digested from the site. It also ocurrend to me later that Regina may not have been used in Europe so ALL may mean something different there than it does here.
I'm not trying to suggest that zirconia and titania are interchangable. I'm looking for someone to point to the documentation that Regina IS titania. That statement in a Volvo tech manual would be ideal, but except for statements by people on the board, I haven't seen any authority cited at all so far.
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Andy '91 745 184K, '89 244 135K, '87 245 lost the rust battle at 225K mi
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Thanks for digging that out, Bruce. I bought my 740 in October, so that was just before I started watching the 700 board. Sounds like Whitefox did his homework and was convinced. Too bad he never followed up as promised with the results of his Volvo sensor.
I have to say I'm still not 100% convinced since I would expect that Volvo would have at least mentioned the difference in their literature and I have been impressed so far with the knowledge of they guys at FCP. But you are on your way to convincing me.
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Andy '91 745 184K, '89 244 134K, '87 245 lost the rust battle at 225K mi
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