Questions and Answers

Nissan Altima No Hot Restart Q. Dear Mr. Vincent Ciulla, My car is 1995 Nissan Altima, 2.4 liter engine, manual with 123,521 miles. My car can be started and drive well when the car is not hot. After driving for a while and the engine warmed up, the temperature of the water reached the normal reading on the meat, and then I stopped my car.

Waiting about 30 minutes, I can not start the car. At this situation, I do hear the start motor works well, and the engine rotates but just does not run. After waiting about another one hour to cool down the engine, the car works fine again. I have taken off the coolant temperature sensor and the air temperature sensor to test the sensors.

I put the sensors into water, changed the water temperature and found the resistance of the sensor changed accordingly, just as same as my repair manual book said. So the sensors seem fine. I replaced the sparkplug and the wires, but it didn't help. What is the problem of my car?

Thanks for your help,
John

A. I wish I could tell you exactly what is wrong and what you need to fix it, but in this venue that is impossible. The best I can do is offer the most likely possibilities based on my years of experience.

The first thing we need to determine is what is missing when it won't start, fuel or spark. When it won't start, take a vacuum line off the intake manifold and spray a good, healthy shot of carburetor cleaner directly into the intake manifold. Use that thin red straw that comes with the carburetor cleaner, it makes it a lot easier.

Then try to start it. If it starts and runs as long as the carburetor cleaner lasts, you know it's a fuel problem. If it doesn't, then it's an ignition problem. Take an old spark plug and gap it to about 0.100". This will be your spark tester. Take a spark plug wire and put it on the spark tester and lay it on something metal so the spark plug has a good ground.

Crank the engine. You should have a nice blue spark. If there is spark, then we know the ignition system is good. If not, we have an ignition problem.

Once we know which it is, we can go on and troubleshoot the problem.