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16v crank position sensor - how it is wired?

 
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Edward
Alfa 33


Joined: 21 Sep 2003
Posts: 368
Location: Bristol

PostPosted: Thu Aug 27, 2020 12:39 am    Post subject: 16v crank position sensor - how it is wired? Reply with quote

some help please on the 16v crank position sensor.

I am trying to connect it onto my Omex 600 for the track car. There are 3 pins in the plug, so firstly - does anyone know - is the sensor 'hall effect'? or the other?

On the 3 pins the best I can seem to glean from the web is:

positive / negative / signal ..... but is this correct?

If it is positive - it is a reference 5v or is it a general 12v supply.

The Omex only has 2 wires - so just trying to work out what you connect to what. I spoke with Omex - but clearly they are not much aware of the plug that is on the engine crank CPS (even after supplying the Bosch part number....). I really need to know how the Bosch plug works before I can speak with Omex and get them to advise how to wire it in. Thanks.
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RFlower
Gold Cloverleaf


Joined: 17 Feb 2004
Posts: 586
Location: S of France

PostPosted: Fri Aug 28, 2020 2:32 pm    Post subject: Reply with quote

Hi Edward.
I have an internal circuit diagram saved as "Motronic ML41 schematic" which I think I downloaded and saved before the links on this forum's information section stopped working.
If so, it was in "Alfa 33 Info V" under "Fuel injection", where it says "For the 16 valve models a Bosch ML4.1 system was used"
The diagram itself is entitled "OPEL OMEGA"
It shows the inputs for engine speed as inductive to terminals 23 and 25 and a switched to mass input on terminal 26.
It is in PDF form, I can send you a copy if you PM me your email.
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Last edited by RFlower on Fri Aug 28, 2020 6:54 pm; edited 1 time in total
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PostPosted: Fri Aug 28, 2020 6:06 pm    Post subject: Reply with quote

Dick,

yep, that might well be helpful.

I was doing a couple of hours research / web browsing / forum searching this morning and have managed to find a few more details - as you allude to. I have been reading through the workshop manuals and found out a fair amount - but still a bit limited.

It is as you say an inductive sensor (not hall effect as I started to think - blind alley!).

This is probably the best information I have found: https://www.alfa-restoration.co.uk/downloads/Alfa-Romeo-33-907-Series-Workshop-Manual.pdf Page 2526

What I am trying to find out (now that I know it is two signal wires to the sensor and a screen cable) is what is on those 2 wires. The overall cable is .... on the outside a mesh screen (that I am guessing goes to earth via the ECU... but not sure - but not too sure that earthing the screen is that important) and there is then a yellow and black wire. Oddly, in the Workshop Manual, it says the output is between 0.5v and 100v .... which doesn't seem plausible to me - well certainly not the 100v any way. I am trying to get my facts (as right as possible) before re-engaging with Omex again and sharing with them what I know. Can't yet see myself telling Omex that I am going to feed their ECU with something up to 100v - yikes....

My e-mail is edwardgurhy@hotmail.com

Cheers,

Edward.
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RFlower
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Joined: 17 Feb 2004
Posts: 586
Location: S of France

PostPosted: Fri Aug 28, 2020 6:54 pm    Post subject: Reply with quote

Sorry, an error there, the input to terminal 26 is for vehicle speed, not engine speed.
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Dick Flower, Nr. Carcassonne. '94 Trofeo 1.4 ie (F), '93 Imola 1.3/1.4 ie (now for parts) (F), '91 1.7 ie (GB)(spare car), '86 Sprint 1.5 QV (F). '87 VW Syncro camper (F), '96 Audi Avant 1.8T (F)
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RFlower
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Joined: 17 Feb 2004
Posts: 586
Location: S of France

PostPosted: Sun Aug 30, 2020 5:59 am    Post subject: Reply with quote

Edward.

Did you receive my email and attachment?
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Dick Flower, Nr. Carcassonne. '94 Trofeo 1.4 ie (F), '93 Imola 1.3/1.4 ie (now for parts) (F), '91 1.7 ie (GB)(spare car), '86 Sprint 1.5 QV (F). '87 VW Syncro camper (F), '96 Audi Avant 1.8T (F)
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Bobkelso
Alfa Sprint


Joined: 09 Aug 2011
Posts: 210
Location: Milan - Italy

PostPosted: Sun Aug 30, 2020 2:10 pm    Post subject: Reply with quote

Hi,
if it can help, I remembered one link at a scheme
similar to the one RFlower talked about motronic 4.1 :

http://alfaromeo33.extra.hu/pdf/16v_motronic.pdf


> at page 11 there is the global electric scheme

the timing sensor has 3 wires and a "3 in line pins" connector,
one is for shield and two are for the inductance (internal coil)

- shield is one of the lateral pin in the connector
- the central pin is ''negative' or 'zero reference' of coil
- the other opposite lateral is 'positive' of coil

- both shield and central 'negative' wires of the sensor goes
to pin 23 of the main connector of the motronic central unit,
maybe the negative wire it put to zero reference
- the 'positive' wire goes to pin 25, probably used as 'signal'
togheter with/respect the zero reference negative wire

> at page 18 there is the detail of the cable connector (S31)
that connect directly at the sensor, where you can identify
whitch wire in the 3 pin row is the screening, the negative
and the positive (but I think you can also measure the resistance
at pins to find the inductance pins and the screening pin)

Ps:
in the part of the manual for marelli ignition of alfa 33 1.3 i.e.
( that has a similar sensor and quite similar ignition functioning)
it is said that the signal from the timing sensor is
about 5 volts, probably also on alfa 33 16v
the signal of the sensor will be few volts

the 100 volts in the manual part about 16v I think is a typo,
consider that pdf images of old alfa 33 manuals we find online
initially had some texts not readable that after a while has
been corrected (rewrited) with patient job by someone I'm gratefull to,
but also introducing some typos you can recognise here and there in the pages
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Last edited by Bobkelso on Sun Sep 20, 2020 12:05 pm; edited 1 time in total
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PostPosted: Mon Aug 31, 2020 8:47 pm    Post subject: Reply with quote

Thanks to both of you .....

I am making progress on this.

Now need to speak to Omex again with what I need.

Bobkelso - all that you have said makes sense - but I couldn't find - even with a good look the bit about "in the part of the manual for marelli ignition of alfa 33 1.3 i.e.
( that has a similar sensor and quite similar ignition functioning)
it is said that the signal from the timing sensor is
about 1-5 volts"

Could you share the reference pls. I had a good read through all of the various reference manuals that are available - but couldn't see that. I am sure it is correct, but might just like to see if for myself when speaking with Omex.

Dick, thanks also for your input and the stuff you sent me. Pretty sure it is now a VR signal at 0-5v with the the pins doing earth shielding, plus and minus. I also know the order of the 3 pins across the block, so I can also share that with Omex, so that I get the best fighting chance of getting things connected up correctly the first time.

The engine when in the bay today - and the Omex only needs for signal connection (which is such a nice departure from Bosch Motronic ML 4.1

Once it can read the crank rotation and the throttle position (which is a potentiometer for the Omex as opposed to a 3 position switch on the Motronic) then the remaining two are easy. (air temp and water temp).

Should hopefully with some further discussions with Omex start to make some progress.

Thanks.
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Edward
Alfa 33


Joined: 21 Sep 2003
Posts: 368
Location: Bristol

PostPosted: Mon Aug 31, 2020 8:54 pm    Post subject: Reply with quote

Sorry there was a small typo on the 3rd from bottom line..... it should say:

The engine went in the engine bay today - and the Omex only needs four signal connection (which is such a nice departure from Bosch Motronic ML 4.1)
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BigAl
P4


Joined: 06 May 2003
Posts: 3141
Location: U.K Surrey

PostPosted: Mon Aug 31, 2020 8:56 pm    Post subject: Reply with quote

nm
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Bobkelso
Alfa Sprint


Joined: 09 Aug 2011
Posts: 210
Location: Milan - Italy

PostPosted: Tue Sep 01, 2020 11:01 am    Post subject: Reply with quote

Hi,
the page referring to the 1-5 volt
is in the large pdf workshop_manual_33_nuova
(the last 33 workshop series manual)
page 2447 of 2576,
(section 04 -22 fuel supply system, paged about T.D.C. and R.P.M sensor)

Air gap: 0,5 -1,5 mm
Internal resistance: 610-750 ohm
Starting (signal to recognise T.D.C. after the
missing teeth on the flywheel I think they mean) voltage
(voltmeter in alternating position):
from 1-5 volt depending condition of the battery,
accessorie and engine rotation

In the image on the same page they say Effective V = some V

On web:
about Voltage from a crank sensor (in general, not the alfa 33 1.3 with IAW marelli ignition)
it seams numbers you can expect could be in the range 5v-12v
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Edward
Alfa 33


Joined: 21 Sep 2003
Posts: 368
Location: Bristol

PostPosted: Tue Sep 01, 2020 10:18 pm    Post subject: Reply with quote

Right, shared that information with Omex and they have now come back with some connection tips.

Need to get the engine fully connected before I give it a go and see if it fires up.

Thanks all.....

E.
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Bobkelso
Alfa Sprint


Joined: 09 Aug 2011
Posts: 210
Location: Milan - Italy

PostPosted: Sun Sep 20, 2020 12:17 pm    Post subject: Reply with quote

Hi,
I walked in this, a detailed descrition of Motronic 4.1,
not the one on Alfa 33 16v, it is Opel(GM/vauxall)
but probably similar:

http://www.primauto.net/DOCOPEL/MOTRONIC_ML4.1_OPEL.htm

Click on each part of the scheme and more data appair


This is the flywell sensor, on Opel car it has this characteristics:

http://www.primauto.net/file%20controllo%20componenti/segnale_di_giri_e___p.htm

and can give 5-10 volts, but 15 volts at the missing tooth
and/or during low revolutions i.e. when starting if I understood the text:

http://www.primauto.net/sito/file%20controllo%20componenti/Segnale_giri_pms.gif
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