My 3.6 is NOT happy. Lulling and bobbing.
 

Hi, it appears as if I have a vacuum leak or some other situation. I'm wondering if something has become unplugged, but nothing is apparent. I don't have a smoker so it's tough to check for leaks. Any thoughts?

https://vimeo.com/201555679


Sent from my iPhone using Tapatalk

Failed 02 sensor?

need to reset idle stabilization....
look at steve wong's 911chips website for details..
good luck..

I'll have a look thanks!

Michael,

If you figure something out, please post your findings. I have been chasing a similar issue w/my 3.6L'd car since pretty much forever - a wandering/surging idle.

I removed the intake last winter and made a smoke machine to track down leaks and was not able to find any. I've cleaned the ICV numerous times and that has not helped either. I've tested various sensors, wiring and connectors and not found anything amiss... I have unplugged the battery to reset the idle stabilization per Steve Wong's instructions, but the issue continues to persist.

It's frustrating to say the least.

I have NOT thrown new parts at it yet as everything I've tested seems to check out A-OK...

I'd love to know if a simple reset of the idle stabilization works for you or if you find something else...

Tom

Here's a link to a video I did last summer I think.

Make sure to turn on CC as I added some notes to the video...

https://youtu.be/YyMOkhpGL54

<iframe width="560" height="315" src="https://www.youtube.com/embed/YyMOkhpGL54?rel=0" frameborder="0" allowfullscreen></iframe>

Also, one other thing to note from the video (which seems to have embedded correctly!) is at the 30 second mark when I press the accelerator to increase the RPM, the engine RPM stutters slightly before increasing. This is another weird trait that I'd like to correct. I keep coming back to the idle micro switch on the throttle body, but as far as I can tell, it is operating correctly...

subscribed
 

Mine does the same thing sometimes when cold. SW chip - idle set numerous times. I know I have a slight leak though so not too worried about it until I fix that.

This looks to be a '95 non-OBDII 993. And it most likely isn't as simple as resetting the idle. You can try to disconnect the battery wait a minute and re-connect. That wipes out idle adaptation on the DME. If it still does hunt after that something else is going on.

By the way, a 993 doesn't have micro-switches for idle and full-throttle like earlier DME version. It uses a continuous throttle position sensor instead. If that is broken this could explain the issue.

Did this happen all of a sudden?
Can you read (scanner) or flash out (CEL) fault codes from the DME?
If you have access to a Porsche scanner (Hammer, PST-2) you can check function of the ICV, TVS, O2 sensor, etc.

Ingo

Yes, it reminds me of when I drove without the oil cap on a few months ago.


Sent from my iPhone using Tapatalk

have you tried unplugging the maf sensor? when you do what happens?

Where does that live?


Sent from my iPhone using Tapatalk

http://cdn4.pelicanparts.com/techart...mall/pic01.jpg

Up above the arrow. It's too big to include but this link shows the four pins visible once the sensor wire is removed.

Turn engine off. Untwist to remove the wire. Restart and see if there's a difference.

Roger that. Thanks Jack.


Sent from my iPhone using Tapatalk

My experience with 964 engines is that the idle is horrible with a light flywheel and original/improper chip.

It used to purr like a kitten. This is a recent development.

My buddy Bryant and I dug around a lot, took off the air intake a few times, and tightened every hose clamp and plug we could find. Removing the plug from the MAF seemed to work, but we had a pesky whistling sound vacuum leak. After messing with it for 30 minutes, we put it back together for the third time and did not hear any more whistle. Now it seems to be running very well! Thank you all for your help!


Sent from my iPhone using Tapatalk