Still cold start probs think it coolant sensor

discussions specific to the 907IE
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hazynut
Posts: 25
Joined: Fri Jun 13, 2014 6:26 pm
model: 907 I.E.
year: 1992
Location: UK Staffs Derbyshire border near Derby

Still cold start probs think it coolant sensor

Post by hazynut »

Hi all, I have been trying to find whats causing my 907 to have to crank for ages to get it to start when cold. I first thought the regulator was at fault but on bypassing the injectors found it held 3bar for hours, so hooking the injectors back into the line I found a steady drop to 2bar, right so I changed the injectors and it held at just under 3bar great, but then went to start it and its still cranking for ages till it starts and then stalls then more cranking finaly starting and running spot on let it run for a few minutes and it starts first touch leave it over night and back to loads of cranking, so now I am looking at the water temp sensor, is it possible to remove the wires from the top to try and start the bike, would this give a signal of resistance to the Ecu as I havent got a multimeter at hand or is this bad practice, :thumbup: Thanks all Re Alistair
nickta
Posts: 295
Joined: Tue Jul 24, 2012 8:54 am
model: 907 I.E.
year: 1992
Location: Cairns, Queensland, Australia

Re: Still cold start probs think it coolant sensor

Post by nickta »

Hi Alistair.

Disconnecting the connector off the top of the sensor would give an open circuit, so the ECU would most likely go into limp home mode. The sensor itself is cheap and there are lots out there. I purchased a couple off eBay a while back for not a lot, from a crowd in the UK. You could put a Multimeter across the sensor and check its resistance. There is a table here or in the workshop manual which has the various resistances vs temperature. The normal way to test them is to drop them in a pot of water and slowly bring it to the boil, while at the same time measuring the resistance. As the water temperature goes up, so the resistance will change in line with the table.

Will post the eBay link when I get the chance for the replacement sensor.

Cheers.

Nick.
nickta
Posts: 295
Joined: Tue Jul 24, 2012 8:54 am
model: 907 I.E.
year: 1992
Location: Cairns, Queensland, Australia

Re: Still cold start probs think it coolant sensor

Post by nickta »

Hi Alistair.

The eBay link for the sensor is http://www.ebay.co.uk/itm/111241510458? ... 26_rdc%3D1

Cheers.

Nick.
Tamburinifan
paso grand pooh-bah
Posts: 1527
Joined: Thu Jun 21, 2007 12:00 am
model: 907 I.E.
year: 1991
Location: Gothenburg, SWEDEN

Re: Still cold start probs think it coolant sensor

Post by Tamburinifan »

Do you knof if TPS is set properly/recently?
How to do:
http://www.bikeboy.org/ducati2vthrottleb.html
318-320mV is normal.
Too low would give hard to start.
Gert

907 I.E. -91
M900 -97
MTS 1100s -07
hazynut
Posts: 25
Joined: Fri Jun 13, 2014 6:26 pm
model: 907 I.E.
year: 1992
Location: UK Staffs Derbyshire border near Derby

Re: Still cold start probs think it coolant sensor

Post by hazynut »

Cheers for all the help . I was working on it last night and found it kicks up pretty fast if I hold the throttle full open when cranking but stalls just after starting. repeat this and she then fires up and runs fine . I will check what's been suggested by the posts on here . Once again thanks all 're Alistair
hazynut
Posts: 25
Joined: Fri Jun 13, 2014 6:26 pm
model: 907 I.E.
year: 1992
Location: UK Staffs Derbyshire border near Derby

Re: Still cold start probs think it coolant sensor

Post by hazynut »

Got It sorted . It was the coolant sensor . Starts first touch of the button. Cheers all. Also the coolant that I lost while fixing it apheared to be a green colour. I haven't seen this before and only have red or blue can I use one of these or is it important to track down some green. Cheers again 're Alistair :)
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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: Still cold start probs think it coolant sensor

Post by paso750 »

good to hear.
One should stick to one colour. Green and blue contain silicate and theoretically can be mixed. The red, pink or purple are silicate free. Never mix green or blue with red etc. there will be chemical reactions like flaking which can i.e. clog your radiator. The manual should say what`s recommended.
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