[A4] '96 12V cold start problem

Jason Gray jason at datsuns.com
Mon Oct 20 23:06:49 PDT 2008

  Thanks all- I have not tried using a OBD II scanner to read the codes yet, 
dont have immediate access to a scanner. I did figure out that my cold start 
problem is about 80% better if I unplug the harness connector for the idle 
stabilization valve (ISV). It then only takes a couple of cranks before the 
engine will sputters to life, rather than 10-20 attempted cranks. I removed, 
cleaned and replaced the ISV but really couldt find anything odviosly wrong 
with it. Applying 12V clicks it fully open. The "resting" position of the 
ISV however is not 100% closed, it still passes a small amount of air when 
OFF. The check engine light was not on before I started messing with the ISV 
valve, but now the light is on. Can I clear the code by disconnecting the 
battery or is using an OBDII scanner absolutely necessary to clear the code?

  I am also a bit suspicious that the vacuum actuated EGR system could be 
contributing to my cold start problem but I have not thus far found anything 
wrong with the ERG system.

The coolant and ambient air temp sensor readings on the dash seem fine. From 
12V.org however, it seem that there is a second coolant temp sensor on the 
left side of the engine that the ECU uses, guess I should check it too.


Jason Gray

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