The Forever CEL

[Ahsai]

If the chain between the cams is off by a tooth, it will definitely give you problems but I thought you had verified that before when you installed the variocam actuator? Sorry it's a long thread if I remembered wrong.

 

The cam deviation should not need driving the car but then I've never tried not resetting the DME after timing so I can't say for sure.

[vza]

I definitely did check and re-check cam to cam allocation before closing it up when doing the solenoid. Just playing devils advocate. I'll reset DME and drive it and scan it tomorrow and keep my fingers crossed. thanks again v

[Ahsai]

A question. Does your cam lock tool go onto BOTH the intake and exhaust cams or it's a short version that only goes on one of the cams?

[Ahsai]

I saw some photos and I think the Boxters cam lock tool can only lock the exhaust cam. Then there is a possibility the variocam actuator/pads may be the problem because the cam sensor picks up the cam position of the intake cam, which is linked to the exhaust cam by the short chain. So even the exhaust cam is dead on, the intake cam relies on the correct variocam actuator/pads to get to the proper position. That's also why as the variocam cam pads wear, the cam deviation goes towards negative even when the exhaust cam timing is dead on (correctly timed).

 

Are the variocam pads close to new?

[Ahsai]

Also any chance you've taken the actuator apart (piston, o-ring, spring, etc) and the small parts are not put back correctly?

[vza]

Yes the locking tool only locks the exhaust cam. I did however replace the wear pads on both banks. I do recall the piston and the spring but not fully coming apart and I know the 0 ring on one side is opposite to the other side. bank 1 o ring the bottom and bank 2 0 ring on the top as far as I remember. Hopefully the DME just needs a reset.

Edited June 3, 2019 by vza

[Ahsai]

Then I don't have other thoughts for now.

[vza]

Well if all fails I guess I'm gonna tare down bank 1 and check  the cam allocation and the actuator for proper assembly but I hope I dont have to.v

[vza]

OK....Ahsai your a genius!! I reset the DME and lo and behold. Bank 1 is +3 Bank 2 0. Drove for about an hr and no CEL so far. Now when I checked it before driving, it was solid 3 and 0 no fluctuation. After driving for an hr or so I checked it again and Bank 1 was fluctuating between 3 and 4 for the deviation, Bank 2 was steady at 0..I did replace the IMS so I'm not sure what thats about. I also may have a pending code for o2 sensors on both banks. What do you think. I added pix of fuel trims as well. Thanks so much for hanging with me and helping out! V

[Ahsai]

Glad to hear some good news! Those numbers look great and are all well within specs.

 

Not sure about the cam deviation jumping between +3 and +4. What I found odd is the cam timing values should have decimal points but yours seem to be always something point zero.

[vza]

Maybe somethings goin on w the software or the OBD plug, I purchased as refurbished from durametric directly. I've been reading that fluctuating cam deviation is a sign of a failing IMS.,should I be worried about this? Could i have damaged the IMS shaft when hammering the new bearing in? Its odd I ran it again and it was stable at 3 again for a good while then started dancing again.Software also said i had P1123 and 1125 code but I had no CEL didn't specify if it was a pending code. Then I tried to activate the CEL w software and it didn't light but it does light when ignition is in the on position. Seems like I fix one thing and 5 more things go wrong. v 

[Ahsai]

Don't worry too much for now. Just drive the car a few days, let the DME fully adapt and read the fuel trims again. P1123 and 1125 means both banks are running rich. Could be the MAF. Let's wait and re-measure first.

[Ahsai]

At this point, I'm truly questioning the cam deviation readings from Durametric on 1999 Boxters. See this thread.

 

However, we do know that your timing is now corrected. Hopefully you don't have any more variocam and misfire codes.

[vza]

Yes I was thinking the same, funny in the referenced article his was reading 3 and 0 as well. Whats up w the CEL, now I'm thinking its not working cause I couldn't test it with the durametric.

[Ahsai]

As long as the CEL lights up when you turn the ignition to the last position before crank and it extinguishes after the engine is started, you are fine. Durametric cannot enable or turn on the CEL. It can't disable the normal CEL operation either.

 

I would just put some miles on the car, drive it a week and see if the CEL comes on.

[vza]

OK...there was an actuation for CEL and it wasn't coming on.....hey it always came on before all the time...not like I'm missing it. I've been drivin it and sounds and runs great....a lot more power! And....I PASSED INSPECTION! v

[Schnell Gelb]

Great that you passed inspection !

After 6 pages of back and forth with symptoms and failed fixes/resets --- for the benefit of future readers of your thread, what exactly do you think was the problem and why was it so difficult to fix ?

[Ahsai]

First congrats! The fact that you passed inspection likely means all your emission readiness flags are set (i.e. misfires, O2 sensor, cats, evap, etc.)

More power because now your variocam is activating properly on BOTH banks and the proper timing fixed the misfires.

 

Now you make me curious. I never saw such a feature in Durametric to turn ON the Check Engine Light only. There's an instrument cluster test that can be activated by Durametric to do bulbs and gauges check. Where is this feature under?

[Ahsai]

7 minutes ago, Schnell Gelb said:

Great that you passed inspection !

After 6 pages of back and forth with symptoms and failed fixes/resets --- for the benefit of future readers of your thread, what exactly do you think was the problem and why was it so difficult to fix ?

Compound problems: Bad DME Bank 2 variocam power transistor + Bad Bank 1 timing + bad Bank 1 chain tensioner.

[vza]

Yes that sums it up....1st bad solenoid on bank 2 which in turn caused the transistor to go out in DME as I understand it. Mis timed bank 1 causing misfire codes ...replaced bank 1 tensioner as precaution 

Ahsai...oddly enough the CEL test is under engine/activations.v

[Schnell Gelb]

Excellent Thread that hopefully will help others who follow.

The diagnosis by Ahsai is invaluable. Yes the Durametric tool is essential but it is the interpretation of the results that is beyond the ability of many of us.

Thank you to both of you for taking the time to chronicle the issue.