RPM's and MAF at Idle
 

This is a screen shot with the engine at operating temperature. I am not seeing a steady reading. When raising the RPM's with the pedal, the RPM's are not steady nor is the MAF readings.

Any ideas why this is happening.


http://986forum.com/forums/uploads02...1528481514.jpg

JEF in PA what do you think?

If there are no codes involved, I would guess that the MAF may be dirty and needs cleaning, or may be on the way out itself. However, if you have codes, I would like to see them.

Have had only one P0139 on a quick scan with the Durametric and cleared it. It has not come back in a few weeks. I removed the MAF and cleaned it with the CRC cleaner a while back. New plugs at 30K and at present just 3k on them. I may have a vacuum leak somewhere. Going to look especially at the foam rubber around the Air Cleaner box. That's about it JFP.

If the P0139 was real, you have an O2 sensor aging out on bank 1-3, which is one of the tools the MAF uses to try and control the mixture. If you also have a vacuum leak as well, that will also drive the MAF nuts.

I would use your Durametric to watch both O2 sensors on bank 1, to see if their voltages are inline. Could be the root of your issues.

Thanks for the advise JFP. I will monitor the voltages. I may remove the MAF and spray clean it again, and use a little dielectric grease on the connector. I didn't do that last time out. Sound OK using the dielectric on the connector?

I would not put anything on the MAF connector. Low and partial voltage sensors can be upset by the slightest things. Clean the connector with a proper contact cleaner and leave it alone.

Thanks for that advise JFP. I didn't think about cleaning the connector when cleaning the MAF, but will do ASAP.