Joined: 21 Mar 2015 Posts: 5945 Location: Brighton
Posted: Tue Jan 08, 2019 8:20 pm Post subject:
I expect it will be fine and at the end of the day its there to check the cat , it has no bearing on the performance of the car.
Its kinda strange that an eml is triggerd far more by save the planet stuff than it is for actuall engine running faults !
I scoped a brand new cat with new sensors today .. it hardly moves from Lambda .. 0.5 v ..
Basically stamp on the throttle to the floor and back up ( engine running ! ).. there will be some switching to rich (higher voltage ) then lean ( lower voltage ) and that proves its working fine .
Front sensors .. so pre cat .. graph both and your looking for a constant rich / lean switch ( 0.2 - 0.8 v ).. they should almost mirror each other .. if one is lagging behind then your getting into ageing faults .. this is where one lambda sensor switches slower than the other and so generates a fault code .
You dont actually have any codes so nothing is out of specs .. but its always interesting to have a look and get your head around these things .. hence i waffle on about it
Fyi .. 997 has different sensors so the above is not true ... these are called wide band sensors . _________________ .
Joined: 21 Mar 2015 Posts: 5945 Location: Brighton
Posted: Wed Jan 09, 2019 8:29 pm Post subject:
Ghianightmare wrote:
deMort wrote:
I scoped a brand new cat with new sensors today .. it hardly moves from Lambda .. 0.5 ..
...dirty... you’ll have the RSPCA on your back now
But nice to see the scope got some use in this thread
.. ill try to leave the cats alone in future
Wasz .. you are correct .. CARB was one of the first emmissions based regulations in the world .. it pre dates OBD .. a police officer could pull your car over .. plug in a tool and check the emissions .. if it failed then it was a tow truck .
Strange that USA has now moved away from the kyoto agreement but hey hoe ... thats politics .
To have a warning system thats based more on the save the planet stuff rather than enigne faults is strange , i dont understand it but thats how it is .
CARB = California Air Regulations Board . _________________ .
I decided to clean my throttle body while I am still waiting for other parts but it was as clean as a whistle.
Took it out for a 25 miles drive today and it still seems fine even driving straight from cold. I'll try to get some readings tomorrow and post up what it is actually doing. _________________ http://euroroadtripper.blogspot.co.uk/
infrasilver Fast & Furious
Joined: 04 Oct 2010 Posts: 8071 Location: East Midlands
Joined: 21 Mar 2015 Posts: 5945 Location: Brighton
Posted: Fri Jan 11, 2019 8:31 pm Post subject:
Ok .. interesting ..
First off .. have you fixed the carbon canister fault ? this will effect the readings .
Second you need to induce a fault .. say unplugging the maf sensor to generate a fault code.
When you clear a dme fault code it will reset the adaptions .. after this you do a r/t of approx 20 miles to get the true reading of what the engine is doing .
RKAT is mixture adaption at idle .. basically the injector duration is increased or decreased depending on what the lambda sensors see .. so a rich mixture and the injector for that cyl will open for a shorter period .. lean and the oposite ... the car will always try to maintain Lambda for each cyl .
Lambda = the correct fuel / air ratio for optimum performance + save the planet ... also called the stoichiometric ratio .
You may well know this stuff already but not everyone does
Your current figures ..
6.9 % is the max limit the car can adapt to , your figures are inside of that limit so the car is compensateing .
This is also only on idle .. the car is running fine when above idle .
B1 is a slightly rich mixture .. its acceptable imho .
B2 has a air leak , its minor but its still an air leak .. the car can easily compensate for this so no real action is needed but if you wanted to then you would smoke test the inlet mainifold .. or at least i would .
There is nothing listed that would indicate a hesitation .. soo ..
The next step would to be to look at misfires .. you may need to drive the car and log these .. i think the durametric can do this .
I would also want to graph the pre cat sensors both sides and graph them on a run .. again im pretty sure the durametric can do this .
This would be the next step and posting the pictures will help .. remote diagnosis isnt easy
I will say .. if this is new kit to you then have a play .. look at what you can then ask questions .
Fault code off hand indicates an old tired cat .. it wont effect performance .. unless its damaged but its save the planet stuff ..
Its always worth bearing in mind though .. a partially blocked cat will have an impact on peformance . _________________ .
I collect the vent pipe from OPC today so will update the tank thread once fitted. I have also rigged up the vac/pressure gauge to the fuel filler cap, again this will be on the other thread.
I did clear the Cat bank 1 code but i have yet to drive the car again, will take it for another spin this weekend once the vent pipe is fitted and I can check the vac gauge at the same time.
My bank 1 Cat may have collapsed internally, I had an aged Cat fault about a year ago and fitted new lambdas, I could hear particles in the Cat when I refitted it but nothing too bad, I checked it again Friday and it sounds worse than it did so I think I will need to source a good used one. I also need to fit a new N/S silencer at some point so a complete exhaust refresh may be coming soon.
I had previously checked for misfires when I was chasing the coil pack fault and there were none showing. All the new coil packs are now fitted as of Friday, I checked the new ones against the ones I removed, all the new ones measured 1.0 ohms and the old ones measured either 0.7 or 0.8 all at room temperature. _________________ http://euroroadtripper.blogspot.co.uk/
infrasilver Fast & Furious
Joined: 04 Oct 2010 Posts: 8071 Location: East Midlands
I fitted the vent pipe that I collected from OPC today and I found that even with a new valve you can blow through both ways and if you suck in the direction that the tank would require to counteract the vacuum in the tank that is more restricted through the two small diaphragms. An old vent pipe I had lying around is exactly the same as the new one but its good to find out how it should work.
I have pulled the car out of the garage to put some miles on it on Sunday and it drove fine up until I stopped at the shop to pick up supplies. I started the car again and I noticed the A/C display flashing and the voltage gauge surging up to over 15v, the engine was also dropping revs in time with the other things happening.
I pulled away from the shop and the car felt sluggish again, could the alternator regulator be actually causing the hesitation?
I've added a video in that thread to show what is happening to the display.
I also noticed when I was running the car in the garage yesterday that when the engine lid fan kicked in the same thing happened, the engine revs drop and stuttered. Battery is only a few months old so I don't think that could be it?
Joined: 21 Mar 2015 Posts: 5945 Location: Brighton
Posted: Sat Jan 12, 2019 8:37 pm Post subject:
Ok .. we have a few seperate posts atm so keeping each one to itself is easier .. you have 3 faults atm as far as i see .
Tank vent .. you have fitted the new pipe .. you now need to do a few miles and watch the vacum gauge .. you will soon see if you still have a problem there i think but as it seemed to take a long trip last time i would ask that you keep the gauge on for a while ..
My concern is a seperate venting issue either with the carbon canister vent pipe or the actuation of the purge valve .. never seen either but im erring on the side of caution here .
Once this is fixed we can move onto the hesitiation fault .. which seems like a fuel pump to be honest . _________________ .
Ok .. we have a few seperate posts atm so keeping each one to itself is easier .. you have 3 faults atm as far as i see .
Tank vent .. you have fitted the new pipe .. you now need to do a few miles and watch the vacum gauge .. you will soon see if you still have a problem there i think but as it seemed to take a long trip last time i would ask that you keep the gauge on for a while ..
My concern is a seperate venting issue either with the carbon canister vent pipe or the actuation of the purge valve .. never seen either but im erring on the side of caution here .
Once this is fixed we can move onto the hesitiation fault .. which seems like a fuel pump to be honest .
Unfortunately 3 threads with different issues but they sort of interlink, unfortunately the voltage regulator has taken priority as I don't want to damage anything by keep running it.
Could the pump be affected by the power spikes? The car ran fine tonight until the A/C unit started flashing, the engine stutters and the fans (interior and engine cooling bay) also fluctuate all in turn? _________________ http://euroroadtripper.blogspot.co.uk/
deMort Zolder
Joined: 21 Mar 2015 Posts: 5945 Location: Brighton
Posted: Sat Jan 12, 2019 9:00 pm Post subject:
ill answer here but it should be in the seperate thread for people in the future who search for faults ..
You have an electrical surgeing fault so it seems .. very strange but easy to prove .. remove the wiring from the alternator .. tape the hell out of the main power lead as you are in a world of pain if that shorts out .
Then run the car .. it wil be on the battery only .. if the fault persists then its not the alternator . _________________ .
I think the hesitancy issue has cleared after fitting a new voltage regulator to the alternator, I'm unsure how or why this has cleared it and I am still apprehensive that it may not be fixed but I have taken it for a 40 mile trip and the issue didn't return at all. I have linked the thread below, it's the same as the link I posted above but with an update and hopefully the answer to the fault
Joined: 21 Mar 2015 Posts: 5945 Location: Brighton
Posted: Fri Jan 18, 2019 10:42 pm Post subject:
Can i just say .. lets see how it goes .
Im not convinced but it seems to have cured the fault .. im struggleing to see how but to be fair i learn all the time and if this is a fix then its something i have learned and so in atticipation .. thank you . _________________ .
+1 on that.........although my sparky mate has told me tales of cars having lumpy tickover, poor acceleration, etc. due to poor battery life and bad earth straps (plus other electrical gizmos). _________________ 2000 Manual 996 C4 Arctic Silver Convertible
All times are GMT - 12 Hours Goto page Previous1, 2, 3
Page 3 of 3
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You can attach files in this forum You can download files in this forum You cannot post calendar events in this forum
![Porsche 911 [991]](./images/models/998.png)
![Porsche 911 [997]](./images/models/Model-997.gif)
![Porsche 911 [GT]](./images/models/Model-GT.png)
![Porsche 911 [996]](./images/models/Model-996.gif)
![Porsche 911 [993]](./images/models/Model-993.gif)
![Porsche 911 [RS]](./images/models/Model-RS.gif)
![Porsche 911 [964]](./images/models/Model-964.gif)
![Porsche 911 [Early]](./images/models/Model-Early.gif)
you’ll have the RSPCA on your back now 
.. ill try to leave the cats alone in future 
