What's significant???? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

doli3415 · 02-09-2014, 07:40 PM

I need help, I have had a misfire on bank one for over six months.. the codes that are generated are 300, 301,302,303, 341, 1340. I have done the following (not necessarily in this order) replaced the O2 sensors, all the spark plugs, the #1 variocam solenoid, had the ECU tested, had the engine compression tested replaced the camshaft position sensor on the # 1 bank. I've check the wiring going to the variocam and the camshaft position sensor, along with the wiring in the rear trunk. I even sent it to an Indy garage and he looked at it for 4 months and gave up.

Sorry so long, here my question(s); the car will run fine until it warms up to about 120-140 degrees then the CEL will start flashing then go solid.

What happens at that temperature? does the cam begin to shift?

fccman · 02-10-2014, 02:45 AM

This may be a dumb question, but, have you checked out the Mass air flow sensor? My 97 base had the exact same issues, until I replaced the MAF. I had also replaced o2 sensors as well.

billj18 · 02-10-2014, 07:53 AM

I noticed that you don't mention changing the coil pack. An easy test is to switch the coil to another cylinder and see if the misfire follows.

Bill

doli3415 · 02-10-2014, 08:57 AM

I should have mentioned that I swapped the coil packs, with no help.

RandallNeighbour · 02-10-2014, 10:12 AM

fccman is definitely on to something. A failing MAF can easily cause the ECU to throw a bunch of other codes for other things. Cleaning it at the bare minimum would be a low-cost way of seeing if it's the culprit.

JFP in PA · 02-10-2014, 10:23 AM

Quote:

Originally Posted by doli3415

I need help, I have had a misfire on bank one for over six months.. the codes that are generated are 300, 301,302,303, 341, 1340. I have done the following (not necessarily in this order) replaced the O2 sensors, all the spark plugs, the #1 variocam solenoid, had the ECU tested, had the engine compression tested replaced the camshaft position sensor on the # 1 bank. I've check the wiring going to the variocam and the camshaft position sensor, along with the wiring in the rear trunk. I even sent it to an Indy garage and he looked at it for 4 months and gave up.

Sorry so long, here my question(s); the car will run fine until it warms up to about 120-140 degrees then the CEL will start flashing then go solid.

What happens at that temperature? does the cam begin to shift?

The cams are supposed to be RPM dependent, not temperature. What concerns me are the two codes P0341 and 1340; 0341 is the code for an implausible signal from the cam position sensor on bank #1, and 1341 is for the timing chain being out of position on the same bank (cam timing).

Suggest the following: Get the car hooked up cold to a Porsche specific scan system (PST II, PIWIS, Durametric), setting the car up to monitor and log coolant temp and cam deviation values; start the car and make note of the cam deviation values, warm the car up until it codes, watching the values. Willing to bet you are going see some odd values.............

doli3415 · 02-10-2014, 05:14 PM

As instructed I hooked up the Durametric with the car cold and checked the values of the cam 1 and 2. deviation on #1 was 25.0 # 2 was -6.0 cold and neither changed after it coded. The car coded after the temperature reached approximately 140 degrees.

Steve Tinker · 02-10-2014, 10:40 PM

Camshaft position #1 shouldn't be as high as 25 deg crk - I thought both camshafts should be +/- 6 deg crk max - or am I missing something ....?

asrul · 02-10-2014, 10:46 PM

The bank where you save?

woodsman · 02-10-2014, 11:07 PM

So position 1 is VERY out of spec. 25 degrees rings a bell- isn't that the range of adjustment for the variocam? I recall someone had a similar problem and the adjuster was stuck at one extreme. At idle it should not be advanced. Search cam timing/deviation and variocam.

JFP in PA · 02-11-2014, 02:05 AM

Quote:

Originally Posted by doli3415

As instructed I hooked up the Durametric with the car cold and checked the values of the cam 1 and 2. deviation on #1 was 25.0 # 2 was -6.0 cold and neither changed after it coded. The car coded after the temperature reached approximately 140 degrees.

Sorry, but bank #1 is way off, it should read +/-6 degrees, not 25. Either a VarioCam issue or the cam is out of time.

doli3415 · 02-11-2014, 03:55 PM

Ok here's something new, I replaced the MAF sensor and then hooked up the Durametric. Both Cams read 0.0 when the car was cold and as it warmed up the cams moved to 25.0 and -6.0 as they were with the old MAF.

no codes were kicked off at first, so I drove the car for a 1/2 mile or so, the car did sound a little like it was running rich and seemed sluggish. after getting it back in the garage the CEL light came on solid with the following codes 341,1340, 1319, 1313,1314,1315.

So the next step in the equation is to time both cam to see if that will rid me of the 341, and 1340 codes along with the emission codes.

Thoughts???

JFP in PA · 02-11-2014, 05:19 PM

You need to focus on the cam timing on bank#1, it is most likely the cause of the misfire codes being that far off.

RandallNeighbour · 02-11-2014, 05:41 PM

Do keep in mind that the computer needs to run a while to get used to the new MAF...

doli3415 · 02-12-2014, 01:52 PM

So I followed the DIY for timing my engine that was posted here, and my timing seems to be correct. The index marks line up as advertised.

Do you think my variocam actuator is stuck? I replaced only the solenoid some months back before I took it to a "professional"

JFP in PA · 02-12-2014, 02:23 PM

Quote:

Originally Posted by doli3415

So I followed the DIY for timing my engine that was posted here, and my timing seems to be correct. The index marks line up as advertised.

Do you think my variocam actuator is stuck? I replaced only the solenoid some months back before I took it to a "professional"

Possible. If you have the Durametric software, you can test activate the VarioCam units at idle and watch the change in the cam deviation values.

doli3415 · 02-12-2014, 03:23 PM

I have activated the cams using the durametric before. When I activate # 2 it drops a little in RPM and regains nothing big. When I activate # 1 it almost stalls out the car. big drop in rpms and regains then drops again. What does that indicate, that the cam is already advanced and when I actuate it, it advances it to a stalling point?

JFP in PA · 02-13-2014, 05:40 AM

Quote:

Originally Posted by doli3415

I have activated the cams using the durametric before. When I activate # 2 it drops a little in RPM and regains nothing big. When I activate # 1 it almost stalls out the car. big drop in rpms and regains then drops again. What does that indicate, that the cam is already advanced and when I actuate it, it advances it to a stalling point?

If it did advance even further, you should see it in the deviation values.

doli3415 · 02-13-2014, 08:15 AM

I've attempted to activate the cams while view the values and for whatever reason I am unable to do so. Any thoughts on why it would almost stall out the car?

JFP in PA · 02-13-2014, 08:27 AM

Quote:

Originally Posted by doli3415

I've attempted to activate the cams while view the values and for whatever reason I am unable to do so. Any thoughts on why it would almost stall out the car?

Because something is wrong with the cam timing on the suspect bank. Either the timing is off, or for some reason the DME thinks it is, either is enough to cause problems...............