What to log/look at in Durametric for Misfires at cold idle?
Thread Starter
|
Registered User
Joined: Sep 2009
Posts: 59
From: Los Gatos, CA
Rep Power: 25
What to log/look at in Durametric for Misfires at cold idle?
I have had misfires on pretty much all cylinders for a long time. CEL comes up pretty much only for cyl 3,5,6 but in Durametric I do see misfires for other cylinders.
This happens at idle, and I notice no power loss. Drives great.
Plugs and coils were all changed about 6 months ago to try to remedy the issue, but did nothing. I also changed the MAF.
I just bought a Durametric and am trying to log to figure out what is going on, but not really sure what to log and what to look for.
Thought about the tappet/solenoid...whatever brackets, but I don't have a whole lot of variation in my cam measurement on the Durametric. There is some, but not a whole lot.
Excel log file in attached Zip and also found here: https://docs.google.com/spreadsheets...it?usp=sharing
Any help would be greatly appreciated!
Thanks!
FYI: Codes I get most are P0300, P0305, P0306
This happens at idle, and I notice no power loss. Drives great.
Plugs and coils were all changed about 6 months ago to try to remedy the issue, but did nothing. I also changed the MAF.
I just bought a Durametric and am trying to log to figure out what is going on, but not really sure what to log and what to look for.
Thought about the tappet/solenoid...whatever brackets, but I don't have a whole lot of variation in my cam measurement on the Durametric. There is some, but not a whole lot.
Excel log file in attached Zip and also found here: https://docs.google.com/spreadsheets...it?usp=sharing
Any help would be greatly appreciated!
Thanks!
FYI: Codes I get most are P0300, P0305, P0306
Last edited by benaslan; Dec 11, 2013 at 11:27 AM.
Registered User
Joined: Jun 2009
Posts: 2,190
From: Benton County, AR
Rep Power: 147
I have a PDF of misfire troubleshooting for the 996 Turbo engine. If you supply me with your email address I can send this to you. It is too big to type in.
I can hit some of the high spots...
The fuel level may be low. With the Turbo there is a problem with the siphon jets one hose failing which means fuel can't be siphoned from one of the two separate basins and even though the fuel level can be above empty the engine is running very low on fuel enough to misfire.
If the tank is down some one thing you can try is to fill up the tank and clear the codes and see if they reappear.
There are I take it no O2 sensor errors? If so then if there is a short circuit to B+ or ground of the sensor ahead of the converter the mixture becomes too lean or too rich and this can cause misfires.
Other possible fault causes: ignition system, injection system, flat base tappets (valve lift fault), mixture too rich, mixture too lean.
There can be a valve lift fault.
Yet another possible explanation is a VarioCam solenoid bracket can crack and the cam timing of one bank can be affected.
Anyhow, if you want the PDF send me an email privately and I'll respond with the PDF.
I can hit some of the high spots...
The fuel level may be low. With the Turbo there is a problem with the siphon jets one hose failing which means fuel can't be siphoned from one of the two separate basins and even though the fuel level can be above empty the engine is running very low on fuel enough to misfire.
If the tank is down some one thing you can try is to fill up the tank and clear the codes and see if they reappear.
There are I take it no O2 sensor errors? If so then if there is a short circuit to B+ or ground of the sensor ahead of the converter the mixture becomes too lean or too rich and this can cause misfires.
Other possible fault causes: ignition system, injection system, flat base tappets (valve lift fault), mixture too rich, mixture too lean.
There can be a valve lift fault.
Yet another possible explanation is a VarioCam solenoid bracket can crack and the cam timing of one bank can be affected.
Anyhow, if you want the PDF send me an email privately and I'll respond with the PDF.
Thread Starter
|
Registered User
Joined: Sep 2009
Posts: 59
From: Los Gatos, CA
Rep Power: 25
It's not fuel level. Problem has been around for a VERY long time. Intermittent, but gotten worse over time.
No O2 sensor errors.
Is there a way to see the vario cam bracket without tearing the car apart?
No O2 sensor errors.
Is there a way to see the vario cam bracket without tearing the car apart?
Thread
Thread Starter
Forum
Replies
Last Post