Q: I have a 1996 Chevy Blazer with 109,000 miles. Every time it rains or sits for one or two days, it does not start until the weather clears or it is dry for one day. This has been going on for the last six months, and my repair shop cannot find anything wrong with the car when they have it for two or three days. Last time this happened was last Friday and Saturday. I had the car towed to their garage on Sunday and he started the car on Tuesday when the weather was good. Any ideas?
A: There are so many things that could cause this problem. Unless you have test gear attached to the vehicle to see if you have lost spark, fuel or fuel injector pulse, it is a guessing game. The first thing I would ask you to do would be to watch the dashboard when you turn on the key. On these rainy days, is the check-engine light on when you turn the ignition switch to the on position? If it is not, you can expect a bad connection at the computer. The 1996 Blazer also uses a lot of relays in the ignition system, such as for the computer and fuel pump. So if any water was entering into the relays, it may have caused the car not to start.
Now, the sure-fire way to diagnose the problem is as follows: when you know that rain or inclement weather is on the way, drop off your car at the repair facility. Let them look at the vehicle while the problem is present.
Q: I have a check-engine light that comes on after 50 miles or so and the fault code is P0144; that is bad oxygen sensor and I have changed them both. But after 50 miles the check engine light comes on with the same fault code. I have had the dealer look at this problem and no one can find a solution. I hope you can help.