CPS Reluctor Wheel

lewisness · Post by **lewisness** » 01 Aug 2017, 17:39

Hello Forum

I'm a little embarrassed to say I just now registered after lurking since 2001. At that time, MVS provided me with a remarkably easy solution for my then-girlfriend's (now wife) non-functioning window switches in her 1995 850 Turbo. I was a god in her eyes for fixing them and blown away how ingeniously these cars were designed and built.

Since then we've had many: 1997 850 T5, 1997 850R, 1998 V70XC, 2000 V70R, 2002 S60 T5, 2002 XC70 and current 2008 XC70.

One of the results of the initial repair (among other things) of my wife's 850 Turbo window switches, was our son who turned 16 this spring and now is a licensed driver. He chose to keep family tradition and get an 850 or S70.

I found a non-running 1998 S70 T5M a few hours from us, picked it up for $500. 154K miles, black/tan. The seller explained the symptoms; sounded like a dead ringer for cam seals. Got it home, found they had throw all the stuff at it you could to solve a random misfire. We opened it up to find new plugs, wires, cap, rotor, cam seals.

The one thing that jumped out at me was how after removing the CPS, the reluctor wheel didn't look square bolted onto the cam. Sure enough, there was fine metal shavings in the CPS housing and one side of the reluctor wheel was ground fresh. We put it back together with the reluctor looking more square or even and tried to start it. The motor cranked and then would stop, like compression lock, like the timing was off, but it would try to start.

Back to MVS to look for the next step. After 20 minutes of searching we went out to start it again, and to our surprise it sarted and ran. Not well mind you, it would not idle but it ran smooth around 3-4K RPMs. No smoke or bad engine noise. We shut it off and tried to start it again. No go. Same un-smooth cranking, and not firing.

I'm sure it will need a new PCV kit, we'll check the timing to see if it is correct.

Would it run at all if the CPS or reluctor wheel was shagged?

-Jim

Post by **Ozark Lee** » 01 Aug 2017, 19:38

I guess the answer is maybe. The car typically will not run at all if it has no cam position signal but what you describe may lead to an erratic signal rather than a missing signal.

...Lee

lewisness · Post by **lewisness** » 02 Aug 2017, 09:49

Thank you Lee. I'll get on to changing some parts & report back. It's been an odd part to source, anyone have one to sell?

Post by **Ozark Lee** » 02 Aug 2017, 18:29

I think I have one from a '99 but I also think it is different. Let me look a the part numbers and see if they are the same between years. If they are the same the next trick will be to find it but that is the sort of thing I would save. A Pick-N-Pull would be an excellent source otherwise.

...Lee

Post by **cn90** » 02 Aug 2017, 18:32

The best bet is local junk yard.

lewisness · Post by **lewisness** » 11 Aug 2017, 11:09

Bought a used reluctor and CPS from VoluParts. There are no more misfires, but it still won't run right. When the engine is cranked, it will crank-struggle-crank then start after 25-30 seconds. It will run between 1500 and 2000 RPMs but dies instantly if you don't feather the accelerator. At higher RPMs (3500-4000) it will run smooth, then buck.

I pulled the timing belt cover to find the cam pulleys aligned with the notches in the cover. Don't really know where to go next.

Here's the condition of the reluctor wheel as I found it upon first inspection:

: Reluctor Wheel.jpg (125.32 KiB) Viewed 2585 times

Post by **scot850** » 11 Aug 2017, 16:38

Is there anyway to get some codes pulled? The danger is you can end throwing away good parts. ETM still sounds like a possible issue and hard to tell until you get it swapped out.

As suggested it is time to check all the major pipework and the intercooler for cracks/splits and loose connectors.

Neil.

lewisness · Post by **lewisness** » 12 Aug 2017, 09:33

Thanks Neil. It's a 98, so no ETM. I'll check the intercooler and related ducting.

Post by **scot850** » 12 Aug 2017, 10:15

Sorry, I am an idiot, and missed the year of manufacture!

The issue can be caused by many different things. It could be crank or cam position sensors, IAT (temp sensor), MAF as well as all the other issues being suggested. The temp sensor can be tested in place at the connection at the power steering pump. There is a set of resistances based on the ambient temperature. Have you cleaned the MAF or tried disconnecting it?

Have you pulled the plugs and looked at their condition as well as the wires/distributor cap/rotor arm? The uneven cranking could be a worn starter or bad battery cables.

Neil.