my 1995 Saab 900se turbo won't start. It cranks fine but won't catch. Could it be the outside temp sensor?

Question

It will occassionally start on a warm clear dry day Which makes me think it is the sensor. If you have any ideas let me know. Where is this sensor located?
Thanks

Answer 1

Most likely it is one of 3 things.
1. A failing DI cassette (this is the ignition coil and module that sits on top of the cylinder head...you have to take this off to replace the spark plugs.) When the condition happens remove the 4 bolts and install a spark plug into one of the coils. Have a friend crank the engine over while you hold the entire assembly with the plug electrode touching a metal surface. No spark may mean a defective DI cassette or crank sensor. See #3... Watch Out..after you have cranked the engine and shut the key off there is what is called a burn off where the plug will be fired.

2. A failing crank sensor- located below your exhaust manifold toward the transmission about 1 foot below the #4 cylinder. If you have a scan tool you can monitor the RPM readings while the condition happens. If you have no reading,then the crank sensor is no good.

3. A failing fuel pump. If you spray carb cleaner into the throttle body when the condition happens and the engine fires up then the pump is no good.

Answer 2

Probably not. NEVER replace any part till you know the problem. If you guess, you will spend lot's of money and time and it won't improve. You may not have this sensor on your vehicle. If your check engine light is on you can get the codes read and that would help. If not it will take a good mechanic and hands on to solve the problem. There are too many things that could cause this problem to try and solve it from here.