Maxima 95' won't start

[comu001]

Hi,

After leaving the lights on overnight, when jump-started the next morning the car won't start. The symptom is that the engine will start only after three or four cranks, it will go at 1.5K RPM for few seconds and then will slowly die. Cranking after such a start will not start the engine again, not even for few seconds. Cranking itself is weird: engine turns for few seconds followed by a second or so of a high load – engine barely turning - and this cycle is repeating.

After replacing the battery - I pulled crankshaft position sensor error code and replaced the sensor. The symptom stayed the same. It looks like there is pressure in the fuel circuit - so I assume the fuel pump is working. Didn't check anything else and I'll appreciate any advice where to start looking. BTW before the night incident there were periodic (once a month) error codes which I would clear about the knock and an O2 sensor :-)

TIA

[maxhopper]

The knock sensor and O2 codes would not cause the problem.

There are two Crank sensors, did you replace the correct one? One is below the crank pulley, the other is on the side of the bell housing (on the side facing the radiator).

[comu001]

I did change one which is sidewise of the pulley. Is there another one? Indeed my manual calls for two:

1. "POS is located on the oil pan facing the gear teeth" - is this the one that I missed?

2. "REF is located on the oil pan (upper) facing the chankshaft pulley" - guess this is the one that I've changed

Are they both the same?

Thanks..

[maxhopper]

1. Yes. You might try pulling the sensor and seeing if there is metal debris on the magnetic part of the sensor. If so, you may be able to clean the debris from the sensor (as the debris may be affecting the sensor's ability to pick up the signal).

2. Correct

The sensors are different.

[comu001]

Did clean the POS sensor of metal debris. Still the engine won't start. I'll try to replace the spark plugs as there is a lot of fouling on them, but I still don't think that I found the problem :-(
Cheers

[loystock]

Make sure your battery connections are clean and tight and that the battery cables have no corrosion.

You may have a weak fuel pump and/or dirty fuel filter. Turn Ignition Switch to ON and listen for humming sound of the fuel pump (in tank, and access behind the rear seat). It will run for @ 5 seconds then auto shutdown. If no sound or the pump is noisy, it's failing.

When was the last time you replaced the fuel filter (located at firewall, adjacent to brake booster). Before replacing the fuel filter, ensure the fuel line is empty - FIRE HAZARD. To empty the fuel line, pull out the Fuel Pump fuse (driver side fuse box) and crank the engine a couple of times. Better yet, you can connect a fuel pressure gauge (T-fitting) to check fuel pressure - 43 PSI with engine OFF and 34 PSI with engine running.

Per your description, you have to replace the spark plugs, preferably with OEM...never use Bosch plugs in Nissan/Infiniti engine.

[comu001]

I'm down to fuel pump which is not powered. The relay is OK - when the key is ON it provides battery volatge on terminal 5. But the connection between the relay and the fuel pump is broken. Also there is no connection between pump's terminal 1 and Fuel Pump Control Module's terminal 3 - my car is not a model for California. I can't locate M4/B1 connector. Help with its location is much appreciated.
Thanks..

[loystock]

Look into the EL (Electrical) and EC (Engine Control) chapters in the link below:

http://www.nicoclub.com/FSM/maxima/1995/

[comu001]

Thanks loystok,

restored the connection between the relay and the pump. Still no pressure in the fuel line, so it should be the pump. A side question: will it be normal for the pump relay to stay closed only for one second after the key is ON? Not sure if there is a closed loop and the ECU should keep the pump ON for a longer time if the fuel pressure is low.

Thanks..

[loystock]

With ignition ON, pump should run for 5 seconds and then shut off.

[comu001]

After key ON the pump is powered for only one second

[comu001]

The fuel pressure at the tank output is only 10psi and it will not hold after power to the pump is off - I powered the pump from a AC-DC power supply. So I guess the fuel pressure regulator is the culprit here.