driving normal and car died. Wouldn't want to start. Replaced the fuel pump and crank position sensor still wouldn't work. Key is in "on" position turns on the fans. No check engine light even during "bulb check"

 

If the check engine light doesn't come on at all, the bulb is either out or removed. Try taking an obd2 reader to it and see if any codes are popping up, you can get them for like 30 bucks online. And does your g even crank?

 

The check engine light was on before it died. I put a scanner to it but it won't read any codes
It does crank but just won't start

 

You said you replaced the fuel pump, see if you can feel or hear it with the key in the on position. You have gas in the tank yes?

 

Keep replacing parts. Eventually you'll find the correct part.

Or you can tow it to an Infiniti dealer and let them tell you which part failed.
If you didn't use OEM parts put the original parts back in prior to towing to the dealer.
Just replacing random parts without knowing the root cause only complicates troubleshooting.

How much gas is in the tank?

Telcoman

 

I don't think your car should turn the fans on when the key is in the on position. When you say it won't read any codes. Do you mean no codes stored it will not connect?

 

Do any of the pre-start indicators (all the lights turning on in the instrument cluster before you crank the motor) turn on or is it JUST the service engine light that doesn't turn on?

Might be a bad relay. You can also put a fuel pressure gauge on the fuel line, access port is on the passenger side tucked into a really **** spot near the battery compartment, make sure you are reading adequate fuel pressure. If you're a hillbilly macguyver you can put a rag over the fuel port and use a screwdriver to depress the schrader valve, I wouldn't really recommend this though... gas spraying out at 50psi and whatnot (hence the rag).

I'm guessing when you say "key in the on position turns on fans" you're talking about the air conditioning fans correct? Or are you talking the two radiator fans?

If you disconnected the battery when changing the fuel pump, and I hope you did, then you probably lost the stored engine codes. In the future you always want to scan BEFORE you unplug so you can hear what the computer is yelling out to you.

What was the reason for replacing the cam position sensor? Just throwing darts at the wall or did you have reason to suspect it failed?

 

The fans turn on with the AC on, with the car in on-but-not-started state. That's the test for them.

Last I checked the passenger fan was for AC, and the drivers fan was for Coolant? Not sure what you mean about this mysterious 3rd fan.

 

won't read any codes? do you mean that there are none stored, or you cant get far enough to pull the codes?

just want to make sure there isn't a no Communication issue with the ECU.

 

Your radiator has two cooling fans, which should not be coming on with key on engine off, and your ac has a fan, or blower motor, which can come on with key on , engine off and ac in the on position.

 

Urban, I was asking about the cabin AC fan, not the radiator fans.

 

I meant his cooling fans. I do not think they should turn on when the car is not running. The blower motor should run without the car running. He has an 03 and i do nit think that those habe two electric fans.

if his cooling fans turn on and he cant see codes then that can be a problem. If he just cant see codes, because they were deleted thats different.

Did you check battery voltage, does your rpm needle move when cranking, or do you have spark? Was there any work done recently? I think the op needs to provide some more info.

i do not believe the g has a schrader valve for checking fuel pressure either. I had to use some adapters and tap into were the damper connects on the passenger side to check mine.

 

That's odd, I've never seen a fuel injection motor that didn't have a valve on the fuel line somewhere in the engine compartment, my '06 it's on the passenger side, I suppose anything is possible though but I can't figure why the manufacturer would omit it since checking fuel pressure is an important step for troubleshooting and bleeding pressure is required before opening the system for repairs.

 

Did you ever think of reading the FSM for your vehicle to assist with troubleshooting?

http://www.nicoclub.com/service-manu.../Coupe/2003/ec

See page EC-598


FUEL PUMP CIRCUIT
Revision; 2004 April
2003 G35 Coupe
FUEL PUMP CIRCUIT
PFP:17042
Description
ABS003L5
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned on to improve engine
startability. If the ECM receives a engine speed signal from the camshaft position sensor (PHASE), it knows
that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when
the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents battery discharging,
thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn controls the fuel pump

Telcoman

 

Are you the original owner of the car? Maybe someone put one there, since I agree it was stupid of them to leave it off. I have an 06 coupe and even in the FSM it says you have to tap into the damper location on the passenger side. If you crack that open also you need a new o-ring or it will leak.