96 850 Turbo 150k, Would not start on 3 occasions, after trying a few times and waiting awhile it finally started, now it won't start at all. (something electronic on it's final leg?) I've got fuel at the Schrader valve, I pulled a plug and grounded it, no spark. I'm thinking it's a relay that sends power to the ignition system or a faulty sensor which is preventing the power to the system. I need to know where and how to check items that may be the cause.

 

Common problem is the Cam Postion Sensor. It's on the Driver's side but I can't remember if it's on the intake or exhaust cam.

 

Any codes?

 

Is There a way to test the Cam position sensor, at $142, not something I just want to try without knowing if it's at fault

I don't have a code reader...should I invest in one ..if so any recommendations

Also the 3 times the car did start after the problem it ran fine for hours.

 

Try visiting a local parts shop such as AutoZone where they provide free OBD-II diagnostic service. If not, I would invest in a decent Actron scanner (CP9175 is my favourite, but note that they can only access engine & tranny ECUs and unable to access ABS/TRAC, Electronic Climate Control, Seats, Instruments, etc...). Less-expensive scanners are so limited in their functions that they are not worth the money. Insome cases they cannot even reset CEL.


JPN

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To Jpn, Where do I find the connector that is refered to in the directions that you sent for testing the CPS. Also is the signal from the CPS only needed during cranking, once the car is running is it no longer needed.

 

As to the connection, see attached pic. I no longer have my 850 so this is the best I can do. With the ignition switch off, disconnect the connector and spray some electrical contact cleaner.

As to its function, I believethe CPSinput is used by the ECU at all times but check with Tech to make sure.


JPN

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I know it has been asked already, but is the check engine light on? If so, are there any OBD codes stored? KOnwing the coeds will help to point you in the right direction to start.

Glenn

 

No codes that I can see...all the dash lights are on since it won't start. Still would like to know if there is a simple way for a DIY to check the Cam position sensor, since all I have is a DOVM

 

Did you inspect the plug yet?
The plugs are known to fall apart and loose connection.
You should be able to find 2 wires to ohm while cranking and get a reading off of.
It is only a refrence sensor.

 

The car ran fine once it started, I've changed the plugs, still no spark,I have nothing coming out of the coil. It seems that what ever the problem was, it didn't allow voltage to the ignition system. Then when it would work, the car would start as normal and run fine. Which leads me to believe that the faulty component is only in use during cranking , because once it starts it's fine. However now it just cranks.

 

But is the cam sensor plug ok?
That also controls the ignition system.

 

Yes I unpluged the CSP plug yeasterday it looked fine

 

Is there a way to test the CPS thru that plug ?

 

I had a very simular problem with my 850. Eg, no spark and no pulse to the injectors.
Turned out to be the crankshaft angle sensor (RPM sensor)

 

I don't think there is a way to actually test the CPS. You can try getting one from a junk yard to save some money.

 

Hi,
I have the exact same problem on my 95 850. I've already replaced the cam sensor and RPM sensor but it didn't solve the problem. my car has always started funny. Here's something interesting. There is no spark from the coil when cranking except when the ignition is released, there is typically one spark. Today, when I had the car running well, I shut it down and checked the spark from the coil again. The coil did spark, intermittantly, but the engine fired and almost started several times. The coil wire was connected to a timing light (the way I check for spark), and no where near the distributor so there is no way for an arc to have caused this. I found that when the engine was firing I was getting a spark from the coil. I then connected the timing light inline with the coil and the car started, with the car running there is strong and fast spark as youwould expect. What I think is happening is the the ECU is not allowing the car to start for whatever reason, but the engine is somehow pre-igniting without any power from the coil. This may be causing the ECU to believe the car is running and then start giving the coil permission to fire, and the car then runs fine.
How is this car firing without the coil attached?
Could this firing cause the ECU to believe it is running, then allow a different (limp home??) condition? (the car runs well when running)
What other sensors could stop the car from starting (beyond crank and cam?)

Please HELP
Josh

 

One person has had this problem due to a faulty immobiliser. Not sure if the immobiliser prevents spark, as my 850 did not have one.


JPN

 

Well I've spent a week without the car and with all of your help (really appreciate it) and some friends here, with the testing we can do, it seems that I don't have theequiptment to test all the sensors that may cause the problem. So I've had the car towed to a local foriegn repair shop we'll see how he makes out. I'll post the results when I get it back, so others may benifit from my experience.Thank you all

 

Thanks. It happens way too often when people ask for help then get it fixed, but don't tell what was done to fix it. Then you see somebody else read the thread sometime in the future and ask what was done to fix the problem.