camshaft position sensor 850/1994

94volvo850 · Post by **94volvo850** » 16 Jan 2005, 22:59

My 94 850 will occasionally not start. Good solid cranking but no start. If I let it sit 2-3 hours it will start with no problem. The diagnostics show an error code for missing and intermittent camshaft position sensor signal
(3-1-4 and 3-2-4). Does anyone knows if that sensor could be the reason of my problem.
New parts: spark plugs, battery, wiring and cap. (within 1 or 2 years)

Thanks!

Da' Moose · Post by **Da' Moose** » 16 Jan 2005, 23:36

When you have your problem is the engine warmed up or is it cold?

If your ECU can not see the Camshaft Position Sensor, it will not know when to fire the spark plugs or the fuel injectors.

94volvo850 · Post by **94volvo850** » 16 Jan 2005, 23:44

More often when the engine is warmed up but also when it's cold

Thanks!

Da' Moose · Post by **Da' Moose** » 17 Jan 2005, 00:04

It would make sense to me that it is having the problem. I have seen over the years that electronic sensors or controllers will fail more often when warm and will

Guest · Post by **Guest** » 17 Jan 2005, 15:01

Thank you very much for your help Da'Moose, I will try your recommandation. Does anyone have information on how to change that sensor? Other than Volvo, is there any other places to buy that camshaft position sensor.

Thanks!

94volvo850 · Post by **94volvo850** » 29 Jan 2005, 11:36

Does anyone hnows if a defective camshaft position sensor could cause the engine to stop if it's been running for 15 minutes.

thanks!

94volvo850 · Post by **94volvo850** » 10 Feb 2005, 12:31

I changed the CPS about a week ago and the problems seems to be gone for good. It took me arround 20 min.

Thanks!

shamrock22 · Post by **shamrock22** » 17 Mar 2005, 18:49

I am having a similar issue. After the car sits over night it appears as if I get no spark at the coil. If I leave the key in the on position for a minute or so it will eventually give spark and start. Been a little bit of a trick to diagnose as I just decide I have no spark then I get spark and the car starts.

I pulled the codes and have both 3-1-4 and 3-2-4. As I understand it one code is sensor missing and one is sensor missing intermittently. Think this is my problem? Also had a code stating RPM sensor intermittently. Looks like the sensor is a bit pricey to guess on.

thanks

94volvo850 · Post by **94volvo850** » 18 Mar 2005, 13:35

I think you should erase the codes and the next time the car will not start, immediatly read the codes. It should give you a better idea.

Good luck!

Let me know if you need help on how to replace the CPS.

shamrock22 · Post by **shamrock22** » 18 Mar 2005, 13:45

Thanks I was all set to do some testing this AM figuring the car had starting difficulty the last 3 mornings in a row. Headed out at 6:00 AM with timing light in one hand and fuel preasure gauge in the other. Turn the key and car starts right up. Go figure. Maybe I just need to bring those with me every morning!

I will keep an eye on the codes and see if they trip again. I am leaning towards the CPS as the problem but want to make sure I completely rule out fuel side. I will try to keep posting as I resolve the issue.