logray

If you activate the solenoid manually and don't hear the engine idle change, then chances are the actuator is toast. The engine should be warm and air conditioning on when you try this. Try both banks to make sure activating the solenoid does in fact change the engine idle. There is no way to service an actuator, they are sealed/welded units that get "tired". Similarly, you don't want to buy a used actuator because there is no way to know it's condition just by looking at it, unless you are a gambling person. The 12.5 ohms seems low, normally I see/get around 13 ohms or higher. Yes if you are going to open the camshaft covers, I would replace actuator and solenoid ($700 USD together) part instead of just the solenoid ($150 USD by itself). "Also, I monitored the camshaft deviation for some time, it is dead steady at 23 degrees and never changes." This might be worth a quick sanity check of the current mechanical timing of the car. Perhaps the cam sproket slipped and timing is off and needs to be corrected. Variocam will not actuate if the mechanical timing is off. This can be done relatively easy with engine in car. Details here: http://986forum.com/forums/showthread.php?t=26418

need your help. Manual gearbox owners: If you have just a couple minutes with your Durametric (or PST2/PIWIS), and your car idling, can you read out these three "Actual values" for me and post them here? Segment A Segment B Learn. progress sens. wheel adapt. Also please include the version of Durametric you are running, This is displayed in the title bar or under help, about. For example I am running 6.1.1.5. ****************************************************************** Technical explanation below, if you are curious ****************************************************************** I'll start it off with my values after 150 miles on a DME reset. Segment A: 1.0002 Segment B: 0.0999 Learn. progress sens. wheel adapt.: 0.0000 One last issue remains with my rebuild. I'm getting occasional random rough running and stumbling below 680 RPM at hot idle. It's pretty random. Sometimes it will even purr along at idle for several minutes without ever hesitating. With any sort of load there is no hesitation. No codes of course, and no misfires. I've already ohmed out my crank sensor and it is in acceptable ohm range (even when warm) 800-1000 ohms and I believe the cam position sensors are good too, as I've checked over the wiring and appropriate voltages to expect. Short of buying an oscilloscope (which costs nearly as much a a flywheel), this is the best tool I think I have on hand in diagnosing the flywheel. (yes I did perform spring test per TSB 1360, although I did note weak springs, little resistance during test, but it did behave the way it said is a "good DMFW" in the TSB) Here is the reason why I think that my segment and learn wheel adapt data is telling me it's the flywheel: "When the values of segments A and B are around zero, e.g. 0.0003, adaptation is complete. The value of learning progress must then be smaller than 0.0005. If the value of learning progress remains at 1.0000, the flywheel is defective. If the values of segments A and B are also at 1.000, then adaptation has not yet been performed. In this case, perform a test drive with three deceleration phases in the speed range from 3000 to 1400 rpm." - from misfire troubleshooting guide Of course, after 150 miles on a DME reset and countless deceleration phases, the values of segment A and B remain around 1.000, and have not changed since, and according to the guide they should be around 0. It never seems to complete adaption since the segments are around 1, but what is strange is my learning prog is 0. Before my rebuild I did read out wheel adapt and it settled on 0.0007, never reaching "good status" below 0.0005. And if I had an o-scope I could do this test for the DMF and CKS: And this test for the CPS and CAMs: Thanks in advance for your time and help!

Yes, but I wouldn't go on a long road trip.

For the cam sensors: From the DME, getting 4.98 volts on pins 1 + 3 and no short between 1 + 2. Tried ohming bank 2 sensor but don't get any readings from it. Bank 1 sensor is too hard to reach to test electrically, I would have to remove the sensor which means removing the AOS. Anyone have an o-scope I can borrow? :| On the subject of the CKS (crank sensor) I heated it up using a heat gun to similate running condition, and it read anywhere between 1005 ohms (hot) to 841 ohms (once cooled down) steady both readings. Is it possible the sensor is bad even though it ohms out OK? I hate to throw away money. Read more about tshooting DMF, short of removing the transmission and replacing the DMF, I can't see any other way to test this easily without an o-scope. Ideas are welcome!

Did some digging on the wiring for the cam position sensor, looks like I need to ohm out pins 1 & 2, I'm just not sure what the acceptable ranges are. 5.2.2 DME pin 1 cps pin 34 dme sensors ground x59/2 pin 21 (engine harness location) pin 2 cps pin 21 dme hall sensor signal (both sensors on same wire) x59/2 pin 14 pin 3 cps pin 53 dme 5v supply x59/2 pin 22

I'm troubleshooting an issue with random rough running values below 2.0, infrequent and random hot re-start idle stumble (difficulty holding 680rpm momentarily), and stalls once or twice after hot and idling. I've already located the specs for the crank sender and ohmed mine out at 839 at 50F, which I understand is within spec of 800-1000 ohms, however closer to the "tired side" as I've read people with new sensors have read closer to 950 ohms. I plan to artificially heat the sensor and re-test. I'm hoping it's not an issue with the DMF, but want to also rule out the cam senders as well. I think I will replace the crank position sensor regardless, since it is a $100 or so part and easy to get to. I can't find any specs on what the cam position sensors should ohm out at or which pins to test. Thanks in advance if someone has those specs. (no codes of course). ;)

Nice work, always "feels" better right! :) Best way to attack leaks are to clean the area, then monitor.

On this car is there a spoiler switch in the footwell below the fuse panel?

+1

And I just want to note this is sort of ironic because I'm troubleshooting a lean running issue myself, but I think I might have it resolved. My solution probably won't be anything like yours though. Here's are some good PDFs for troubleshooting P1124 and P1126: http://www.renntech.org/forums/index.php?app=forums&module=forums&section=attach&tid=20397 http://www.google.com/url?sa=t&rct=j&q=porsche%209103%2F2%20.6%20bar&source=web&cd=8&ved=0CGAQFjAH&url=http%3A%2F%2Fwww.renntech.org%2Fforums%2Findex.php%3Fapp%3Dcore%26module%3Dattach%26section%3Dattach%26attach_id%3D3722&ei=ZU9BT4LPFezXiALe86SyAQ&usg=AFQjCNE1hV_uxNLV9-ZcquKHPRwtSnXE-Q&cad=rja

"Although, I've seen a few posts where the valve wasn't replaced and didn't cause any issues. However, I don't want to take any chances with fuel + hot engines." You can reuse the test port cap a few times. I would replace it maybe after 4 or 5 times. But if you want to be meticulous about it, replace it. "From the links above, fuel pressure should be 43.5 to 58 psi when pump is activated by Durametric?" 3.3 bar with engine idling. 3.7 bar ignition on engine off, activated by durametric. Then with the pump running, engine off, count off 30 seconds or less the pump should fill a 1 quart container. "How about intake manifold vacuum? How many inches of vaccum am I looking for?" Good question! This varies greatly depending on you altitude. If you are near sea level I would guess a normal reading is between 17 and 18 inches of mercury. If your reading is drastically lower than that, it could indicate a vacuum leak. Reading the gauge can tell you other things about the health of the car too. Also can you please post your fuel trims (FRA and TRA) from Durametric (you don't need to turn the car on to get this)

I like PIAA myself.

I think a trip to the dentists would be a lot more enjoyable. Thankfully, I have not had to remove my dash yet. :)

GOOD choice.

Thanks for the follow up!

This is a difficult problem indeed. I see you took the advice and replaced the injector. Sorry that didn't work out. From here I would inspect the wiring, both visually and with an ohm meter. The impedance between the positive injector lead & coil pack lead to the DME should not differ dramatically from the rest of the non-misfiring cylinders. There should not be a short to ground. The connector should be inspected as well. Have you boroscoped the cylinder? Have you repeated the compression test with a squirt of oil in the cylinder (if the numbers on 4 are slightly less than the rest) ? (rings or <cough> slipped sleeve) Have you tested intake vacuum (intake vacuum can tell a lot of stories)? What does the plug in #4 look like compared to the rest? Can you post some numbers from the DME at idle? Post everything you can, including fuel trim, maf readings, etc. Can you post the compression and leak down numbers?

First and foremost, there is no mention of battery testing or replacement. That would be the first place I would look. Have you looked at all of the main power leads? These are the ones that are normally suspect (corroded or poor connection). Main positive from alternator to starter to jump point in engine bay. Ground strap from engine to chassis. Ground strap from battery to chassis. There are others as well but much more difficult to access... Main positive lead from battery to main fuse box. LONG Positive lead from fuse box to junction above transmission. Positive lead from junction point to jump point on engine.

That's a little more than what mine looked like, but not too different. It's probably not intermix, but just normal condensation. Once I cleaned it and stopped driving the car for a couple miles without ever getting to operating temp, it never came back. Now I only drive the car if I intend to warm it up to operating temp, even if it means going "the long route". If you want to be certain it's not intermix, have a look at your coolant, what does it look like? If it looks mayonnaisey too, then there is a definately problem. With classic intermix, the oil will mix into the coolant system, but the coolant rarely mixes into the oil system.

The harbor freight A/C manifold test kit works for me and very easy to use, everything you need in the one box to test fuel pressure. I think I got it for $30 or $40 a long time ago, it was on sale and I used a 20% coupon. THe price might have gone up by now. Yes the harbor frieght vacuum gauge works fine. Since you've eliminated a lot of stuff for those codes, I haven't seen a test for fuel pressure with engine off or engine on idling. You can test crankcase vacuum, but you should probably actually test intake manifold vacuum. If your reading is low, it might indicate a vacuum leak or otherwise, and I can't recall if you've done a smoke test yet or not.

What's your intake vacuum? The gauges are cheap, and it's easy to pull an intake hose to test with.

Have you tested fuel pressure & quantity, also fuel pressure regulator? Easy to do, just get the right tool for the job!

You could test the fan motor directly by applying 12 volts positive at the fan wire connector junction point (remove wheel well liner to access).

That's a very reasonable charge for that type of service. Glad it was something simple.

Clean it off, take it for a good spirited drive or two or three and see if it's back. Count me for another person that has experienced this, I used to have a 1 mile commute to work and back. Then I stopped driving and got on the bike, no yellowish stuff forming on it.

Whether the screen has an affect on MAF readings or not, I would leave the screen in as it would help prevent any large debris from entereing your engine. Perhaps such debris might have accidentially found their way past the filter (or if you forget to install the filter), or broken/ruptured filter/etc. I also would be interested to know if removing the muffler has any affect on air mass flow readings. With a perfectly sealed unit, I'm guessing the muffler is going to not introduce unmetered air and rather create some sort of dampening affect with a higher or lower pressure zone the air must pass over. The fluid dynamics analysis would be interesting. Perhaps one positive might be if the muffler or hose were leaking and introducing unmetered air past the MAF. I used to have this "cold air kit" and I did notice a little more noise.