Saturday, December 04, 2004

Damn Cars

On Wednesday, I got my car back from my mechanic after 2+ weeks (and $2k+) in the shop. The damn thing repays me by refusing to start Friday night. Cars always seem to choose the worst time to do this and mine is no different. After a nice dinner at Maggiano's (a little over-rated but still good) it decided to be dificult.

This is the second time it has done this - the first time was last summer in Vail. It cranks a stumbles but won't quite catch and after a couple of tries it smells strongly of gas. Classic signs of an over rich condition. In Vail, after many tries (and weakening battery) and while awaiting rescue by the Triple A, it occured to me that I could lean it out by reducing fuel pressure - and that I could do that by simply removing the fuse for the fuel pump. I Poped out the fuse and it started right up and ran for 10 seconds until fuel pressure drops to zero. Reinstall the fuse, and it started right up and carried up home without further incident. Kinda McGuiver if I do say so.

This trick worked last night as well. I (apparently incorectly) attributed the Vail problem to alititude. I use fuel injectors that are much larger than stock and have the pulse width about as short as possible during start-up. I would not be suprising to have an overly rich condition at very high (9000 Ft.) altitude. After both incidents, the Check Engine Light illuminated requiring a reset after Vail - last night it went out by itself after a few minutes.

This condition could be caused by a number of things, bad O2 sensors, bad fuel pressure regulator, bad crank position sensor, or stuck fuel injector. Pulling the code indicates a O2 sensor problem. So I will replace the O2 sensors ($119 x2 @ Bavarian Autosport ) and see if things get better, if not I will add an adjustable fuel pressure regulator and underhood fuel pressure guage.

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