850 1997 No spark from coil

Athenasinsanedad · Post by **Athenasinsanedad** » 16 Jan 2010, 14:19

Hello
I been having an issue starting the car for the past week. It wouldnt start then it would for a couple days. The last day it ran it started fine no problem turned it off and 5 mins later it wouldnt start and still wont 2 days later. I replaced the coil and still the car will not start. I have no spark from the coil. I am trying to figure out the problem and seen some posts about it could be the crank sensor. I do not know where that is located. Any help would be greatly appreciated.

Post by **jblackburn** » 16 Jan 2010, 14:23

Sounds like the crankshaft position sensor has failed.

https://www.matthewsvolvosite.com/forums ... 2&p=106848

Take a look about halfway down that page at Rob's 2nd post of pictures. That is the sensor you're looking at.

Athenasinsanedad · Post by **Athenasinsanedad** » 16 Jan 2010, 14:29

Thanks for the reply. We took the cam shaft sensor out and it looks brand new. Is there a way to test to see if that is the issue? I found another place saying maybe the crank sensor but I am not sure where it is.

Post by **jblackburn** » 16 Jan 2010, 14:40

Yes. You'll need a voltmeter.

This section is for the older 700/900 series cars, but the same basic concept of testing applies to yours:
http://www.volvoclub.org.uk/faq/EngineS ... ion_Sensor

Take a look at the 'testing' section there.

Post by **tjts1** » 16 Jan 2010, 15:15

Mine did this when the cam sensor failed. You'll have the same symptoms if the cam sensor or crank sensor fail. You can't tell if the sensor is good or bad by simply looking at it.

Athenasinsanedad · Post by **Athenasinsanedad** » 16 Jan 2010, 15:48

ok tested the crank sensor which has only two terminals and it read 390. Does that mean its good?

Post by **jblackburn** » 16 Jan 2010, 16:25

Right, the older ones had 3; there are only 2 terminals on the 850.

Yes, that one sounds good to me (you did test while trying to start, right?). As long as there IS resistance there, it is outputting a signal. In that case, it's probably the cam sensor - even though it looks new, it can still be bad.

Change the seal while you're in there - we have a write-up here:
https://www.matthewsvolvosite.com/forums ... =1&t=24925 but it sounds like you've already got it down if you removed it already

Toplights · Post by **Toplights** » 17 Jan 2010, 04:51

jablackburn,I also have a no start problem with my V70,my crank sensor reads 276Koms,do you recon thats ok or failing?thanks.

Post by **jblackburn** » 17 Jan 2010, 05:11

As long as there IS resistance there, it is outputting a signal.

If there was not any between the terminals, then you would have reason to suspect it's bad.

However, if you have an intermittent no-start or running condition, this test can't help with that. The sensors tend to act up at an older age when they get hot.

Athenasinsanedad · Post by **Athenasinsanedad** » 17 Jan 2010, 15:18

is there a way to test cam sensor?