I hae a 1994 Nissan Sentra that has an inconsistent starting problem. The car either cranks and starts immediately or will crank over only. When there is a problem, I can get it started by cranking the engine over for a very long time provided the battery doesn't go dead or sometimes it will start if left alone for several days or weeks. When I can get it started after a problem, it starts up right away when turned off and started again.
There is fuel at the engine so it doesn't appear to be a fuel pump problem. There is also spark at the distributor from the coil so that part seems okay as well. Putting starting fluid spray in the air filter doesn't help.
The problem seems more likely to happen at the beginning of a day when it's been cold out (under 50 F).
The spark plugs and wires were changed in the past and the car runs okay if it starts -- it's just a slow car without much power.
The service engine light is on sometimes. The car can have the starting problem no matter if the service engine light is on or not. I don't know how to get a code other than take the vehicle to a dealer.
My guess is there's a sensor issue, but if so, which sensor? Has anyone had an issue like this and what would the recommendation be?
Thank you.