build diary

May 8, 2006: When I was down in Texas, my car was misbehaving.
It was showing signs of a vacuum leak and more embarassingly, it would blow big clouds of smoke when I left from a stop. It was really looking like a car with no valve seals. But I knew that couldn't be it because it had been fine. Given what I was seeing on the O2 sensor, I spent my time trying to fix it with tuning.

Until I got back up to Colorado. Despite tweaking my fuel map to sort out the high-power gasoline, I still had the big cloud of smoke. When pulling the filter off (again) to check to see if there was a problem with the butterfly synchronisation, I noticed that the aft throttles were pretty oily. They get the PCV line so there's always going to be some, but this seemed excessive. I tried removing the line from the PCV valve and boom! No more vacuum leak and no more smoke. There's always going to be some air coming in through a PCV at idle but this certainly indicated a problem. I pulled the valve out and it was hollow! I can't explain that one. Maybe the vibration of the trip to Texas caused the end of the possibly 16-year-old valve to break off. Despite disassembling the baffles in the valve cover, I couldn't find the missing pieces. Reassembling with a good valve showed that all my problems were solved. Sigh. It's always a bit of a hassle when something like this happens, but it's really embarrassing when it happens during a test. The bad idle that Larry commented on wasn't my fault at all and it was just poor timing. Oh well, I guess there's always some sort of regret.

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