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Still cold start probs think it coolant sensor
Posted: Wed Apr 29, 2015 3:36 pm
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,

Thanks all Re Alistair
Re: Still cold start probs think it coolant sensor
Posted: Thu Apr 30, 2015 1:40 am
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.
Re: Still cold start probs think it coolant sensor
Posted: Thu Apr 30, 2015 4:37 am
by nickta
Hi Alistair.
The eBay link for the sensor is
http://www.ebay.co.uk/itm/111241510458? ... 26_rdc%3D1
Cheers.
Nick.
Re: Still cold start probs think it coolant sensor
Posted: Thu Apr 30, 2015 6:48 am
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.
Re: Still cold start probs think it coolant sensor
Posted: Thu Apr 30, 2015 9:35 am
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
Re: Still cold start probs think it coolant sensor
Posted: Thu May 07, 2015 7:48 pm
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

Re: Still cold start probs think it coolant sensor
Posted: Thu May 07, 2015 9:06 pm
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.