How to use a Durametric OBD reader on a Boxster. - 986 Forum - The Community for Porsche Boxster & Cayman Owners

If you clicked on the link thinking you would find all the answers... not yet. I have started to get serious with my Durametric, but am struck by the lack of information available. There are some introductions, but they don't go very deep, two that I have looked at recently are these. https://www.youtube.com/watch?v=Caw9xWiIoE0 https://www.youtube.com/watch?v=0sYoIbkjOz8 A longer introduction from Jake Raby https://www.youtube.com/watch?v=e5YgEiQsuck What I would like to see is details of how to do specific researches. The above video by Raby explains how to verify the cam deviations. On my 2000 2.7l I recently checked the fuel trim by selecting the following in Actual Values: * RPM * Hot film MAF * Actual angle for camshaft bank 1 * Actual angle for camshaft bank 2 * Mass air flow * Adaption range 2 (FRA) bank 1 * Adaption range 2 (RKAT) bank 1 * Adaption range 2 (FRA) bank 2 * Adaption range 2 (RKAT) bank 2 Which gave the numbers attached to this post and which seem to be good. http://986forum.com/forums/performance-technical-chat/83379-trying-understand-fuel-trim-help.html I am now going to try to check the O2 sensors and the ignition timing... will add that information as I go. I invite others to add their own tests and results. I need to understand how to read the results of the test, what are the allowable limits and what does it mean when limits are not met or exceeded. For example I gleaned this while looking through a post: "You can check the MAF voltage with your****Durametric Should show 0.9 volts - 1.1 volts ...with key on engine off 1.2 volts - 1.5 volts engine running at an idle"

ask yourself if maf readings matter. if trims are good and 02 sensor is working then maf readings must be ok, hey? otherwise, what problem are you trying to solve? in your other post you think you are down on power. any of the info you are referencing is for closed-loop, part throttle operation. if you are having a max power issue then car is running open loop so o2 sensors, stft not in play. given that trims are good then maf readings are accurate. i would look at fuelling - filter, injectors, perhaps fuel pump. these things can perform within spec at part throttle operation but start to fail when at wide open throttle. this won't get detected by the ecu until the lack of fuel starts to cause pre-detonation and knock. perhaps check your knock readings and see where they are.

Quotes source post: 653036

+1for the above.... Also your looking at "Hot Film MAF" readings... Your car has a Hot Wire MAF sensor so "Hot Film MAF" readings are meaningless. Another point...fuel trims are expressed a little differently by the Durametric (Porsche) They break them out by RPM or engine load "FRA" I believe is under load or mid RPM range. So to look at FRA fuel trim when the engine is at idle is meaningless...

Quotes source post: 653036

I'm not going to be asking my self anything for awhile since I don't know much about all this! Hopefully with help from you guys I will get a handle on it. My low power problem is a lack of low end torque... and I know there is a problem because at the moment my 2000 Boxster S has (temporarily) a 2,7l engine in it (actually it has the original engine from this car) and it has a lot more torque at low revs, a LOT more. This one only starts to come alive as the revs go up. Thanks for the clarification on the MAF. I will check the knock sensors in my next test.

so both 2.7, but one into a 5-speed and one into.a 6-speed. 6-speed seems to have more torque than the 5-speed. gearing difference? aftermarket or larger rims (big wheels change your final drive ratio)? resonance flapper not working - depending on how it fails you may not get a code? sorry, this should probably be in the other thread and leave this one for how to interpret durametric readings ...

When your looking at data from an OBDII scanner or any diagnostic tool.... the data can be miss leading or meaningless if not taken under proper conditions. Things like STFT's.... LTFT's...Pre cat O2 sensor readings ...post cat O2 sensor readings....those readings (all readings) need to be taken under specific engine load and or RPM conditions to be relevant. Something as simple as intake vacuum test readings are meaningless if not tested under correct conditions and in the proper way. I suggest you go to youtube and look up "scannerdanner" take the time to view as much of his content as possible. He is very good at diagnostics.. he uses oscilloscope type scanners most of the time...but you can learn good diagnostic methods from him and how OBDII data is used and applied and under what conditions. There is a huge misunderstanding for most people concerning the OBDII system...... it's primary function is ....Catalytic Converter Performance.... Engine performance is secondary..... and tuned to Catalytic Converter performance needs.