Questions and Answers
Nissan Altima Dies, Won't Restart When Hot
Q. We have a 1993 Nissan Altima, 2.4 litre engine, automatic transmission and 148,000 miles. My car starts, and runs for about 10 or 15 minutes, then dies when the car gets warmed up, even while driving.
When you try to re-start the car, it will not start for anywhere from 15 minutes to 1 hour, when the car cools off. We checked, and changed the fuel pump, but the car is still doing the same thing. Do you know what could be causing this to happen?
Also, when we took off the cap, rotor, and dust cover, there was a little bit of oil inside the distributor. Could this cause the problem? Would we need a new distributor? We have also checked for codes, but there are none coming up on the computer in the car. Thank you for any help you can give on this matter.
A. The most common cause of this symptom is a bad Crankshaft Position Sensor (CPS) inside the distributor.
The Crankshaft Position sensor, located in the distributor, monitors engine speed and piston position.
When the rotor passes between the photo diodes and Light Emitting Diodes (LED) the slits in the rotor plate cut the light being transmitted to the photo diode from the LED. This generates rough-shaped pulses which are changed into ON/OFF signals by the wave forming circuit. The Engine Control Module (ECM) interprets these signals to calculate engine rpm and cylinder position.
Crankshaft Position Sensor
The unit has a rotor plate and a wave forming circuit. The rotor plate has 360 slits for 1° signals and 4 slits for 180° signals. Photo diodes and light emitting diodes (LED's) are used for the wave forming circuit.
If there is oil in the distributor coming up past the shaft seal, then it is possible the oil may be filling in some of the slits and causing the engine to die.
However, it is much more likely the CPS itself is bad. Sometimes you can confirm this by letting the engine run for about 30 to 45 minutes with the hood closed, then tapping the side of the distributor with a small hammer. If the engine dies, you have a bad CPS for sure.
If it doesn't, the next time you drive it and it dies, check for spark at once. If there is no spark then you probably do have a bad CPS. The problem is if you check it when the engine is running normally, it will check out as good.