Camshaft position sensor OR Variable Valve Timing Solenoid?

xerxes66 · Post by **xerxes66** » 17 Oct 2017, 17:43

Car usually runs ragged at idle but sometimes (10%??) it runs very smoothly. Codes indicate a camshaft position sensor problem. I'm on a fixed income so I've gotten three different ones from the salvage yard and they seem to work about 1/2 hour and it's back to the ragged idle.
I also got two used solenoids, cleaned them in carburetor cleaner, and tested them w/12V - they clicked like they were working well so I put them in and it stills usually runs poorly.
Any ideas? A new camshaft position sensor is very expensive and I need some options.
Thank you in advance!!

xerxes66 · Post by **xerxes66** » 17 Oct 2017, 17:44

Sorry... it's a 2000 C70 LPT coupe!!

Post by **erikv11** » 17 Oct 2017, 19:53

Well you said even ideas are accepted, so here are a couple:

A cam sensor that's bad enough to throw a code will usually not operate the car. It's a catch-22: you rarely see a valid CPS code because when the sensor dies (which is usually all at once, not gradually) the car shuts down before the code can be set. And there is no way the three from the salvage yard are bad. Likely all 4 are good and you don't need to be buying a new one, not for the lifetime of the car now as you've got 4. I would check the wiring to the CPS, is the connector plug from the harness OK? COP wires not routed too close to the wiring for the CPS or other sensors?

The VVT solenoid will usually throw a code for that, not for the cam sensor. However - how is the wiring to the solenoid, it isn't crimped under the cover is it? I've read of that being a problem.

Is the engine in time properly, any recent timing belt or water pump service?

Post by **precopster** » 18 Oct 2017, 03:06

The base beneath the cam sensor which is made of plastic has been the culprit on a couple of recent posts if it's a Denso sensor.
With C70s they often are a hybrid when it comes to adopting new hardware and you could be talking about the older metal housing and aluminium base designed Bosch sensor.

Due to the sensor's location it's really difficult to see if the base is damaged and if the sensor is seated properly. Try to photograph the sensor with a Macro setting so you can take a close-up look.

What codes are you actually pulling from the car?

Post by **abscate** » 18 Oct 2017, 03:37

When it is running really rough these codes can be spurious. Take a good look at your induction and vacuum hoses for leaks before you chase a CPS, the odds are 10:1 in favor of entropic degradation of rubber over a component failure.

How many miles are on it?

Is your yellow label ETM nice and so shiny and clean you can eat off it?