2G TSI AWD ATX poor idle quality

[MacHinery]

95 Talon Tsi AWD automatic, 160,000 miles, bone stock. The car lopes at idle, dies occasionally and will die in gear at a stop if you don't give it some throttle. A code reader displayed 0443, 1400, and 0300. I just got the car, so I am uncertain about the maintenance up to this point. I took it to a mechanic and he thought it was either the timing being off or the EGR valve. I noticed yesterday that the idle will drop about 100 RPM when the lights are turned on. The RPMs will go back up when the lights are turned off again. The lope doesn't go away with the RPM change. Alternator puts out approximately 14 volts. It seems to run fine anywhere above an idle. I am planning on plugs and wires in addition to checking the vacuum lines as a starting point. I have checked out several threads with similar issues, but I was hoping that the symptoms were specific enough for someone to identify the culprit. Thanks in advance for your patience with this newbie. I have had only 420a powered DSMs up til this new one. Sincerest apologies for the lengthy post.

 

[gixxer6]

http://www.dsmtuners.com/forums/maintenance-repairs/447043-p0443-solution-questions.html

http://www.dsmtuners.com/forums/newbie-forum/84535-obdii-code-p1400.html

http://www.dsmtuners.com/forums/newbie-forum/260269-multiple-cylinder-misfire-p0300.html

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)


this may help with your idle issue.

 

[MacHinery]

I did a boost leak test. Various leaks included the BISS, the hose that goes from the valve cover to the intake, the throttle body stem, and the injector seals. The first two have been corrected, but the parts store did not have anything for throttle body and only had two kits for the injectors. I replaced the spark plugs with NGK BPR6ES. By color, the old Denso plugs were good to perhaps a bit rich. I plan to replace the plug wires as well, the parts store called a half hour after I got back to the shop to say that the plug wires had come in...ugh! I guess I will be going back tomorrow. The TB on my donor car appears to be new, so I may just swap them out. Anyway, the idle did not improve as of yet. I will do some research on the EGR and check it out. I am also wondering about the TPS. I will update again when some progress has been made.

 

[MacHinery]

I guess you should always check the easy stuff first. Something didn't look right when I was putting on the new plug wires, so I got out the service manual and found that the #2 and #3 plug wires were switched. Maybe I shouldn't feel so bad, two mechanics worked on it before I got it and neither one found the crossed wires. Anyway, CEL went away instantly and idle did improve somewhat. Rear oxygen sensor looked pretty crusty, so I am planning on replacing it. I hope doing that and replacing the TB shaft seals and injector seals to seal up the boost leaks will have it purring. Acceleration is definitely there, but MPG seems on the low side. I hope the next update will be the final resolution.