Vehicle Speed Sensors

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SteveP
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Re: Vehicle Speed Sensors

Post by SteveP » 29 Mar 2016 12:30 pm

You'd NEVER get 40mpg out of a 360 injection. Scraping 30mpg is hard enough and the three that I've owned have all been the same :lol: LH2.4 is far better than the crappy LE Jet fitted to 360 injections. Carbed 360's are a lot better on fuel, under most situations (eg. except from cold start with choke, probably).

Back on topic, these 3d printed holders are really cool :D
1989 - Volvo 360 GLT
1985 - Volvo 360 GLS
2008 - Volvo S60 SE Lux

Ride_on
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Re: Vehicle Speed Sensors

Post by Ride_on » 29 Mar 2016 06:47 pm

I think you're right, the difference in LH2.4 is mainly the idle mode which is very lean (or close to), thats what allows me to get 40mpg using pulse and glide in idle. Probably not much benefit for normal driving though. Might work on B200F.
1980 345 DL_______1987 360 GLE (project car restored to GLT spec and B230FT'd)
1984 360 GLT______1987 360 GLT
1983 360 GLS______1989 360 GLE
1985 340 GL_______1986 340 1.4
1985 360 GLS______1995 940 SE 2.3 Turbo Estate (daily)
1987 340 GL 1.7

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Chris_C
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Re: Vehicle Speed Sensors

Post by Chris_C » 05 Jul 2016 09:44 pm

So, firstly an apology to Ride_On. It's taken me a ChrisStandardTimePeriod to get to this.

There are only a few pictures as I didn't have my camera nearby and had to use my phone.

First job was to take the 400 series dash and work out what the power supply section was doing to the standard sensor.

Image

Voltage is supplied via the on dash voltage reg (10 V, datasheet and measured, less than 10 mV ripple measured) and supplied to the Vehicle Speed Sensor (VSS) with a Zener (unidentified, mine is crimped in a way I can't see the last letter(s)). Measured voltage at the Zener is again 10 V, with less than 10 mV ripple.

First test was on the original 400 series sensor. 3 - 4 mA current draw measured, Vout at the sig line of the sensor was clean 0 - 10 V square wave with 4 periods over a 360 deg rotation of the speedo head. These periods as far as could be measured were of equal mark space ratio.

Scope was set to storage mode, an arbitrary time window chosen and the speedo head spun at a representative speed as would be seen during normal use. Output waveform was crisp with negligible rise and fall times.

Image

Second test was on Ride_On's sensor. Firstly, the 3D print is of good quality and the fit to the 400 dash was very good. No modification in any respect and screw holes aligned perfectly.

Image

As scope was set to storage mode and so tests would be equivalent, the representative RPM test was conducted. A snag was noted at this point, the rise time of the sensor was significantly different to that of the 400 series original.

Image

I have used the family of sensors that Ride_On is using before and hadn't seen this behavior previously. As can be seen in the photo above, the VSS was supplied with an LED attached to ease testing. It is an ultrabright white LED, total system draw was 19 mA with this attached so on a hunch I removed the LED and repeated the test.

Image

Rise time issue solved. Mark space difference to the original sensor is down to the consistency in the operator spinning the speedo head, not the sensor itself.

All other tests conducted showed clean 0 - 10 V output square wave, 4 periods over 360 degree rotation of speedo head, these periods as far as could be measured were of equal mark space ratio. Current draw of sensor again read 4 mA.

Conclusion:
If Fake was running, I'd have no hesitation of running one of these sensors for a full road test. As far as I can test, they are identical in performance to the original unit.

Ride_On, well done chap. Just sorry again that it's taken me so long!
'89(F) 340 GL F7R (ex B172k) - Fake -> SBKV 300 Runner Up 08, 12 - NASLR Time 15.7secs
'03 S60 D5 SE, '91 (J) MX5
Ex:
'91(H) 340 GL B14.4E - Kar; '88(F) 360 GLT B200E - Jet -> BKV 300 Runner Up 09; '89(G) 360 GLT B200E - Beast

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bogbasic
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Re: Vehicle Speed Sensors

Post by bogbasic » 06 Jul 2016 11:36 am

Well done, sir.
1988 340 1.4 GL, 218k, 5 door (Grey Bess). Gone to CBA.
1991 340 1.7 GL, 64k, 5 door, petrol blue (Deep Blue).
1988 360 2.0 GLE, 140k, 5 door, ocean blue metallic (Blue Bess).
1989 340 1.7 GL, 108k, 3 door (Red Ness).
More info here!

Ride_on
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Re: Vehicle Speed Sensors

Post by Ride_on » 06 Jul 2016 09:28 pm

Nice equipment and good testing! The 4 mA choice was a bit of a guess to get a decent signal to noise without drawing alot of current. I'm pleased the original designer chose the same. I presume this is unloaded without the computer connected. LED was just what was lying around and mainly so basic function can be checked while confirming mechanical accuracy. The 20mA was within the ability of the sensor, the rise time maybe a function of the resistor in the 440 circuit, but as you say the LED is just temporary.

I didn't realise the 440 would be working on 10V, I think the 940 is working on a 12v signal, I must recheck that, but it should not be critical if the computer input is designed sensibly, and it should be happy with either supply voltage.

Did you confirm the needle is still moving ok?
1980 345 DL_______1987 360 GLE (project car restored to GLT spec and B230FT'd)
1984 360 GLT______1987 360 GLT
1983 360 GLS______1989 360 GLE
1985 340 GL_______1986 340 1.4
1985 360 GLS______1995 940 SE 2.3 Turbo Estate (daily)
1987 340 GL 1.7

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Chris_C
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Re: Vehicle Speed Sensors

Post by Chris_C » 07 Jul 2016 02:51 pm

Ride_on wrote:I presume this is unloaded without the computer connected.
Indeed, just the scope probe. I would imagine the ECU itself was a high impedance input so should be relatively similar?
Ride_on wrote:I didn't realise the 440 would be working on 10V, I think the 940 is working on a 12v signal, I must recheck that, but it should not be critical if the computer input is designed sensibly, and it should be happy with either supply voltage.
Fake is working on 12V un reg'd, which likely explains some of the issues I've previously seen with my speed sensor. The fact I've got unsheilded cables near the HT side doesn't help either, it's on the list of things to fix.
Ride_on wrote:Did you confirm the needle is still moving ok?
Yup, it's all still working fine :)

I don't know how many prototypes you went through, but the one you sent me just felt like a clean well engineered solution. I was sad (in an engineering "awwww bugger" way) when I saw the rise time issue because it had all seen so good up until then, but then happy again as soon as I realised it was a red herring and wouldn't occur in the real world and likely that the original would have done the same thing.

I really hope all the car enthusiasts that have cars using this sensor (and there really are lots, VDO put it in a lot of things at the time) find the work you have put in and benefit from it. The only thing different to the original is the fact you have to solder the wires from this sensor to the flexi PCB somehow, but it has the ability of keeping cars running and being electrical is one of the parts that car people seem to be naturally dubious of.
'89(F) 340 GL F7R (ex B172k) - Fake -> SBKV 300 Runner Up 08, 12 - NASLR Time 15.7secs
'03 S60 D5 SE, '91 (J) MX5
Ex:
'91(H) 340 GL B14.4E - Kar; '88(F) 360 GLT B200E - Jet -> BKV 300 Runner Up 09; '89(G) 360 GLT B200E - Beast

Ride_on
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Joined: 26 May 2009 05:34 pm
Location: Belfast, N. Ireland

Re: Vehicle Speed Sensors

Post by Ride_on » 07 Jul 2016 09:20 pm

I think it was the 2nd 3D print, just to correct some mistakes. The original sensor position was in the wrong place. Electronics was designed and unchanged but I was not sure how the LH2.4 is designed. There maybe a pot divider at the ECU which will draw some current, but doesn't need much. I check it out soon.

I made a 3rd after that to adjust the height, yours was cut down a little for clearance. Incidently how does the magnetic sensor height compare with the original? ie the top interface surface when the screw holes are to the magnetic sensor surface.

I only got the car back a few weeks ago and killed myself last week doing the clutch in a 12hr marathon. Got hols comming up so will install mine soon.

At the end of the day the main benefit is to have a proven holder, I plan on sharing it on TinkerCAD so anyone can load it up, copy+modify, print to your local print guy etc.
1980 345 DL_______1987 360 GLE (project car restored to GLT spec and B230FT'd)
1984 360 GLT______1987 360 GLT
1983 360 GLS______1989 360 GLE
1985 340 GL_______1986 340 1.4
1985 360 GLS______1995 940 SE 2.3 Turbo Estate (daily)
1987 340 GL 1.7

Ride_on
Posts: 2233
Joined: 26 May 2009 05:34 pm
Location: Belfast, N. Ireland

Re: Vehicle Speed Sensors

Post by Ride_on » 22 Jul 2017 12:43 pm

Just to update this, have installed and used mine, but not sure it is making any difference. I still have some minor issues with high idle when cold, maybe to do with the throttle body adjustment.

Anyway holder is public on Tinkercad, select, print and pay if you want one. I don't know if solid printing is necessary, probably work fine with their normal percentage, as there is not much intermediate volume.

https://www.tinkercad.com/things/d7KWyZdxanN
Last edited by Ride_on on 18 May 2019 04:08 pm, edited 1 time in total.
1980 345 DL_______1987 360 GLE (project car restored to GLT spec and B230FT'd)
1984 360 GLT______1987 360 GLT
1983 360 GLS______1989 360 GLE
1985 340 GL_______1986 340 1.4
1985 360 GLS______1995 940 SE 2.3 Turbo Estate (daily)
1987 340 GL 1.7

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bogbasic
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Re: Vehicle Speed Sensors

Post by bogbasic » 22 Jul 2017 02:49 pm

Epic work.
1988 340 1.4 GL, 218k, 5 door (Grey Bess). Gone to CBA.
1991 340 1.7 GL, 64k, 5 door, petrol blue (Deep Blue).
1988 360 2.0 GLE, 140k, 5 door, ocean blue metallic (Blue Bess).
1989 340 1.7 GL, 108k, 3 door (Red Ness).
More info here!

Ride_on
Posts: 2233
Joined: 26 May 2009 05:34 pm
Location: Belfast, N. Ireland

Re: Vehicle Speed Sensors

Post by Ride_on » 14 Mar 2019 11:25 am

So another update.

Car has been working well enough with the speed sensor, but through a minor error I drove the car without the speedo working (cable not engaged properly).

On applying full power the ECU decided to set the idle to about 1800rpm, and nothing would change it other than switching off/on.
I though this might be an corruption issue due to low voltage or EMC interference from the ignition or something but on research it seems this is a symptom of having no speed detected when full power is detected. Noone seems to understand why this is, possibly limp home thing, and there maybe an error code. But reinstating the speedo drive cable fixed it anyway.

So this at least is a reason to have the VSS installed.
1980 345 DL_______1987 360 GLE (project car restored to GLT spec and B230FT'd)
1984 360 GLT______1987 360 GLT
1983 360 GLS______1989 360 GLE
1985 340 GL_______1986 340 1.4
1985 360 GLS______1995 940 SE 2.3 Turbo Estate (daily)
1987 340 GL 1.7

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