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Recommended Posts

Posted

I don't have the equipment for fuel pressure test or the intake air test. I have noticed that the CEL comes on more quickly as I have been driving again more... I did a three hour drive on Saturday and did a cold start, warm start actuals test. I also am including the most recent faults codes report as it is consistent that the cylinders that are recording the misfires are nearly all of them but are intermittent.

@Ahsai can I ask you to look at these reports counting the misfires at cold start and warm start and let me know if these give any additional insights? Thank you!

Actuals_Reports_Archive.zip

Posted

Nothing much new other than the cold start log shows the misfires are more prominent at cold start during the open loop phase.

Can you log the coolant temp (or engine temp as Durametric calls it) and intake air temp during cold start?

Also one thing you can try is e-gas recalibration. Just leave the key in the last position before crank for 60s, then turn the key to OFF for 10s then you're done.

 

I think you would need to bring it to a good shop for further diagnostic.

Posted

Thanks Ahsai. This model (AE) has a cable throttle so no e-gas present. I am going to try another test with the engine cold in about 2hrs. 
I just cross posted this on Pelican as well. I've been a long time member there and thought that we might get lucky with some sharing.
Will post the updated reports here as soon as I have them. Thank you,

 

 

Posted (edited)

AFAIK, all 2004 996s (2000+ and all AWD for that matter) have e-gas. Are you saying you see a physical throttle cable on your throttle body?

Edited by Ahsai
  • Moderators
Posted
46 minutes ago, Ahsai said:

AFAIK, all 2004 996s (2000+ and all AWD for that matter) have e-gas. Are you saying you see a physical throttle cable on your throttle body?

 

Duncan is correct, that car should be E-gas...............

Posted

Hello guys. "AE" is my abbreviation for Anniversary Edition. Unlike all the other 996.2's that have e-gas, the AE has a cable throttle. I think it was a nod to the past throttle feel.

Appreciate everyone weighing on on the thread.

  • Admin
Posted
10 minutes ago, innov8 said:

Hello guys. "AE" is my abbreviation for Anniversary Edition. Unlike all the other 996.2's that have e-gas, the AE has a cable throttle. I think it was a nod to the past throttle feel.

Appreciate everyone weighing on on the thread.

 

Really? I see nothing in the parts list about different throttle body or cable for the model year 2004 AE.

How about a photo?

 

Posted

innov8, in addition to what Loren showed about, the AE can't use a wired throttle because it comes with PSM, which uses e-gas to throttle the engine.

 

If you really have a cable sticking out of your throttle body, that can't be a stock throttle body/engine.

Posted

Hello again. I'm not with the car... and haven't actually seen the cable for the throttle linkage. I'm only going on what I've read but clearly there are different sources.

http://press.porsche.com/archive/products/press_kits/press_kits_2004/PDF/new/1-11_Carrera_Release.pdf
Read the first sentence on page 2 of this Porsche Official Press Release.... "This engine is equipped with a direct accelerator pedal linkage that provides spontaneous response and the anniversary car also has a mechanical rear-axle differential that enhances traction and acceleration potential. Together, these changes make the 40th Anniversary 911 one second faster in the acceleration run from a standing start to 120 mph (200 km/h), a feat the car accomplishes in 16.5 seconds."

When I get home later, I will try looking for a cable and see it is visible to photograph.

Posted

Prolly marketing loss in translation. Note the next paragraph says the 40th comes with PSM as a standard feature. If you have wired throttle, PSM can't modulate the throttle.

 

Anyways, these are the pics of the wired throttle (left) and e-gas throttle (right). Yours should look similar to the one on the right.

 

pic02.jpg

Posted

Hello... so I'm a victim of marketing. Ironic. My 996 AE is definitely E-Gas as shown above. 
I'll try the e-gas recalibration as noted above.
below. These include the oil temp and ambient temp as requested... you'll see the misfires counting then going away when the throttle drops down to idle. Could this be the purge valve sticking (part no 
83-08019561) or would that have shown up in the durametric testing? Going to try and find a vacuum leak with a home made smoke machine this weekend.

Let me know if the actual values with the temps show anything new that I should run down. Thank you again for everyone input.

Archive.zip

Posted

The IAT and coolant temp look consistent (assuming they are clsoe to the ambient temp). Sticky purge valve is possible but it should have tripped an evap code.

Posted

@Ahsai Thank you... I did the e-gas recalibration and am still getting a slight roughness in the cold start and a very slight hesitation when pulling away in first from a stop... the rpm drop for 1/2 a second as I pass 2k and then comes back and pulls hard and smooth.

While researching smoke machines, I found your hack of a fog machine into a smoke machine—Brilliant! I have one and am planning on testing for vacuum leaks this weekend. Still determined to make as many maintenance and repairs on my 996 as I can. I keep telling myself that is part of the pride and joy or ownership. Understanding and repairing things is becoming a lost art in the world today. I like the idea that we can still fix most of what needs fixing... with the support of communities and resources like your posts.

Thank you again for all your help thus far. I noticed another post where someone has gotten the same codes but I don't think that they have gotten into the different data points as you have guided me. I'm going to share this thread there and maybe they can benefit from some of your advice as well. 

Posted

"Understanding and repairing things is becoming a lost art in the world today." <- Can't agree more!!

 

There are a few things you can test just to eliminate those:

- check crankcase vacuum (using a $35 digital manometer) and make sure it's ~5" of water

- check the purge valve you mentioned (check if it's leaking).

- check for intake air leak

- check fuel pressure at idle

  • 4 years later...

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