Spinning on the starter - wont kick over

[bentombed]

Hello - after about 3 years of trouble free riding I started my 2002 Scura up a week or so back to head out,for the day and it stalled.  its not started again - whenever i try the bike will just spin on the starter. fuel pump works, all the other electrics work but there is no spark.  I have checked the plugs, coils, HT leads, relays and fuses - all were good.  I then checked the crankshaft sensor, the resistance between the poles was in spec, but despite a few efforts i could not get a reading from the sensor itself.  the TPS tested in spec - i havent checked the voltage though. 

My guess is that the crankshaft sensor is cooked and that i need to order a replacement,  if its not that what else should i be checking? the bike has a few mods to the wiring, the fuel pump is on its own fuse and i have added a few additional earth wires that keep it going and charging well. 

any help or suggestions greatly appreciated. 

 

 

Edited October 26 by bentombed

[pete roper]

Buy a phase sensor. They’re cheap.

[Pressureangle]

3 hours ago, pete roper said:

Buy a phase sensor. They’re cheap.

Not so cheap in the U.S.

I have purchased mine from Romania on eBay. It seems they're a common part on many Fiat/Lada but nothing that was ever sold in the Western hemisphere. 

[audiomick]

1 hour ago, Pressureangle said:

--- It seems they're a common part on many Fiat/Lada but nothing that was ever sold in the Western hemisphere. 

Maybe not in the U.S.A. I have the impression that the thing is a fairly common part in Europe.

This was linked by Beard (author of Guzzidiag) in the German forum:

https://www.ebay.de/p/1705283308

Searching the part,

Facet Sensor 9.0032

produced this list of hits

https://www.startpage.com/do/dsearch?q=Facet+Sensor+90032&cat=web&language=deutsch

 

About $20.- . One could consider that "not cheap", as opposed to 5 bucks or so, but compared to €326,- for the Guzzi part, I'm not complaining... 

https://wendelmotorraeder.de/phasen-und-umdrehungsfuhler_gu01721600-p-1024014.html?ref=expl

Edited October 26 by audiomick

[gstallons]

Uhhhh. 326.50 Euro ? $378.96 ! That's pretty steep. 

 Do you know how to test this ? 

[audiomick]

20 minutes ago, gstallons said:

 Do you know how to test this ? 

The sensor? No, not really. 

I've often read of a "visual inspection", i.e. take it out an see if it has developed a bulge in the middle. Apparently that is the way they die, and is inevitable.

Also, I gather Guzzidiag can test it, but I haven't tried that.

And someone wrote here recently about testing it with a heat gun, but I don't remember the details, or in which topic that was.

[gstallons]

Can you use a DVOM ?

[audiomick]

36 minutes ago, gstallons said:

Can you use a DVOM ?

I can't say for sure.

The post about testing with a heat gun that I referred to was this one, from @Pressureangle

I understand that to mean: The thing is a magnetic sensor. It should never go open circuit, I believe. If it is going open when it gets warm, it is broken, even if it looks good when cold. But I am making assumptions there, and would welcome someone else's confirmation of the logic. 

[pete roper]

http://meat and doria 87074

[pete roper]

Whoops. That didn’t seem to work but it’s the part number. I buy them from Europe for not a lot.

[audiomick]

2 minutes ago, pete roper said:

http://meat and doria 87074

Was that supposed to lead here, or somewhere similar?

https://www.meat-doria.com/product_meat/87074

[Pressureangle]

2 hours ago, audiomick said:

The sensor? No, not really. 

I've often read of a "visual inspection", i.e. take it out an see if it has developed a bulge in the middle. Apparently that is the way they die, and is inevitable.

Also, I gather Guzzidiag can test it, but I haven't tried that.

And someone wrote here recently about testing it with a heat gun, but I don't remember the details, or in which topic that was.

All inductive sensors operate on the same principle- they're just tiny generators. They are a tight coil, just like the primary side of an ignition coil. When the reluctor tooth passes the tip, it generates a voltage; when the tip passes, it generates an opposite voltage. So the two tests for any inductive sensor are Ohms and AC voltage. Ohms differ between sensors; you have to know the nominal value to test. AC voltage is simple, just connect a DMM (preferably RMS) and read the AC voltage. At very low RPM they output low voltage, which rises with speed. Where the problem with this specific sensor comes, is they break down over time with heat cycles, and the common experience is intermittent poor running/stalling which worsens over time. Works when cold, quits when warm, worsening with cycles. The coil inside open circuits as it swells from heat, so testing ohms while heating is the answer. Testing my failed sensor proved exactly what I saw in the symptoms; failure right as the motor warmed up. I measured consistent open failure at about 150* (edit, 170,) warm enough to be uncomfortable to a hand. 
And yes, it was swelled in the middle enough to make it worrisome to pull out. 

Edited October 26 by Pressureangle

[bentombed]

37 minutes ago, pete roper said:

http://meat and doria 87074

I found and ordered a couple of those 13 euro each. about 30 euro postage. ( 90 australian delivered) 

[docc]

12 minutes ago, Pressureangle said:

All inductive sensors operate on the same principle- they're just tiny generators. They are a tight coil, just like the primary side of an ignition coil. When the reluctor tooth passes the tip, it generates a voltage; when the tip passes, it generates an opposite voltage. So the two tests for any inductive sensor are Ohms and AC voltage. Ohms differ between sensors; you have to know the nominal value to test. AC voltage is simple, just connect a DMM (preferably RMS) and read the AC voltage. At very low RPM they output low voltage, which rises with speed. Where the problem with this specific sensor comes, is they break down over time with heat cycles, and the common experience is intermittent poor running/stalling which worsens over time. Works when cold, quits when warm, worsening with cycles. The coil inside open circuits as it swells from heat, so testing ohms while heating is the answer. Testing my failed sensor proved exactly what I saw in the symptoms; failure right as the motor warmed up. I measured consistent open failure at about 150* (edit, 170,) warm enough to be uncomfortable to a hand. 
And yes, it was swelled in the middle enough to make it worrisome to pull out. 

Are those degrees Fahrenheit?

[bentombed]

8 minutes ago, Pressureangle said:

All inductive sensors operate on the same principle- they're just tiny generators. They are a tight coil, just like the primary side of an ignition coil. When the reluctor tooth passes the tip, it generates a voltage; when the tip passes, it generates an opposite voltage. So the two tests for any inductive sensor are Ohms and AC voltage. Ohms differ between sensors; you have to know the nominal value to test. AC voltage is simple, just connect a DMM (preferably RMS) and read the AC voltage. At very low RPM they output low voltage, which rises with speed. Where the problem with this specific sensor comes, is they break down over time with heat cycles, and the common experience is intermittent poor running/stalling which worsens over time. Works when cold, quits when warm, worsening with cycles. The coil inside open circuits as it swells from heat, so testing ohms while heating is the answer. Testing my failed sensor proved exactly what I saw in the symptoms; failure right as the motor warmed up. I measured consistent open failure at about 150*, just warm enough to be uncomfortable to a hand. 
And yes, it was swelled in the middle enough to make it worrisome to pull out. 

that description fits perfectly -  bike would run worse as i approached work or home, (about 25ks each way) but would start fine.  The idle had started to wander - it sounded like it was searching for fuel, and would stall at the lights every now and then.   when i last had the bike running it was to warm it up to balance the throttle bodys and tune it. was treating the wrong symptom.  

Now that you mention it, the sensor was really hard to get out, i had to get some fuel hose pliers to get enough force on it.  I didnt know to check for swelling, i'll take a look at that when the new one arrives. need to find the right sized o-ring for it too.