dodge dakota owned for 10 years...no starting problems until recently failing to start on occasion in cold weather...new battery...will turn over but fails to fire....178 k miles....runs great when it does start...any suggestions
Scanning the powertrain control system can give you a lot of information, including trouble codes and important engine data.
If the engine won't start cold, it could be something like a defective engine coolant temperature sensor.
When cold, the coolant temperature sensor sends the appropriate signal to the PCM (Powertrain Control Module). When the PCM sees the cold temperature signal, it provides a rich mixture through the fuel injectors. Lots of fuel is mandatory to fire a cold engine.
When the engine warms up, the PCM sees a warm coolant temperature signal, and therefore commands a leaner fuel mixture (less fuel) to maintain proper emissions output.
The sensor may be showing warm, when cold, and causing all the grief.
Again, you really should start with a scanner. If everything checks out OK, then test for adequate spark and fuel pressure while the engine is cranking and not starting.
Low fuel pressure (clogged filter or bad pump) may also produce difficult cold weather startups.
Last edited by TechHelp2 (2/28/2010 1:56 AM)