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deMort
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Joined: 21 Mar 2015
Posts: 5723
Location: Brighton


PostPosted: Tue Jan 08, 2019 8:20 pm    Post subject: Reply with quote

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 Very Happy

Fyi .. 997 has different sensors so the above is not true ... these are called wide band sensors .
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Ghianightmare
Monza


Joined: 25 Apr 2017
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PostPosted: Tue Jan 08, 2019 11:30 pm    Post subject: Reply with quote

deMort wrote:


I scoped a brand new cat with new sensors today .. it hardly moves from Lambda .. 0.5 ..


...dirty... Hand you’ll have the RSPCA on your back now Very Happy

But nice to see the scope got some use in this thread Thumb
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wasz
Magny-Cours


Joined: 28 Dec 2012
Posts: 2690


1999 Porsche 996 Carrera 2

PostPosted: Wed Jan 09, 2019 5:44 pm    Post subject: Reply with quote

deMort wrote:
Its kinda strange that an eml is triggerd far more by save the planet stuff than it is for actuall engine running faults !


I heard the origins of these lights is in emissions regulation. In the states it was a legal requirement that a light alerted you to emissions fault, and the car would not pass inspection The regulators didn't care about engine faults... and mfrs didn't want to concern drivers with minor faults that could be picked up at service.
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deMort
Zolder


Joined: 21 Mar 2015
Posts: 5723
Location: Brighton


PostPosted: Wed Jan 09, 2019 8:29 pm    Post subject: Reply with quote

Ghianightmare wrote:
deMort wrote:


I scoped a brand new cat with new sensors today .. it hardly moves from Lambda .. 0.5 ..


...dirty... Hand you’ll have the RSPCA on your back now Very Happy

But nice to see the scope got some use in this thread Thumb



Floor .. ill try to leave the cats alone in future Very Happy

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 .
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infrasilver
Fast & Furious
Fast & Furious


Joined: 04 Oct 2010
Posts: 8002
Location: East Midlands

2001 Porsche 996 Targa

PostPosted: Wed Jan 09, 2019 10:20 pm    Post subject: Reply with quote

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.
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infrasilver
Fast & Furious
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Joined: 04 Oct 2010
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Location: East Midlands

2001 Porsche 996 Targa

PostPosted: Thu Jan 10, 2019 10:36 pm    Post subject: Reply with quote

deMort wrote:
Fuel adaption figures if you can get them please .. Rkat , frau , frao .. or tra / stft depending on the tester .


Got some readings today as you requested. The RKAT ones don't seem to be uniform in comparison?



I also had a fault code pop up, P0420 code 40, Cat Conv efficiency bank 1
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deMort
Zolder


Joined: 21 Mar 2015
Posts: 5723
Location: Brighton


PostPosted: Fri Jan 11, 2019 8:31 pm    Post subject: Reply with quote

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 Very Happy

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 Smile

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 .
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infrasilver
Fast & Furious
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Joined: 04 Oct 2010
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2001 Porsche 996 Targa

PostPosted: Sat Jan 12, 2019 3:05 am    Post subject: Reply with quote

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.
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infrasilver
Fast & Furious
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Joined: 04 Oct 2010
Posts: 8002
Location: East Midlands

2001 Porsche 996 Targa

PostPosted: Sat Jan 12, 2019 7:15 pm    Post subject: Reply with quote

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?

See my other thread http://911uk.com/viewtopic.php?t=131774

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?

Could this issue actually be my hesitation issue Question
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deMort
Zolder


Joined: 21 Mar 2015
Posts: 5723
Location: Brighton


PostPosted: Sat Jan 12, 2019 8:37 pm    Post subject: Reply with quote

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 .
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infrasilver
Fast & Furious
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Joined: 04 Oct 2010
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Location: East Midlands

2001 Porsche 996 Targa

PostPosted: Sat Jan 12, 2019 8:54 pm    Post subject: Reply with quote

deMort wrote:
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?
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deMort
Zolder


Joined: 21 Mar 2015
Posts: 5723
Location: Brighton


PostPosted: Sat Jan 12, 2019 9:00 pm    Post subject: Reply with quote

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 .
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infrasilver
Fast & Furious
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Joined: 04 Oct 2010
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Location: East Midlands

2001 Porsche 996 Targa

PostPosted: Tue Jan 15, 2019 10:38 pm    Post subject: Reply with quote

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 Dont know

http://www.911uk.com/viewtopic.php?t=131774
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