I have a 1994 Ford F150 small block truck. It has about 130,000 miles on it & runs great. However, on cool foggy days the check engine light comes on. Then it does not come on again until it is another cool/cold foggy day. What’s up with that?
Maybe a parts store can read the codes and tell you WHAT is making the light come on… Then you can decide whether to fix it or ignore it…
I don’t think you have a OBTII style system so you need to go to a auto repair shop to have the codes checked. To me it sound as if the engine isn’t getting warmed up properly and the ECM senses that. Might be a defective thermostat
The ‘Check Engine’ light is how your truck’s ECM tells you it thinks there’s a problem. First thing is to extract the code. This link describes the process, since your truck is OBD-I, and includes the codes list. http://www.troublecodes.net/Ford/. Post the codes here, and we can help further.