gpshogan

I have a 1995 Lexus ES300. 3.0L. It wont start. I am pretty sure this is a fuel issue. I tired a little starting fluid and the motor fires then dies.
I pulled the fuel pump. I tested the fuel pump to a battery and it works. The fuel pump is not turning on when I out the key in the "on" position. However, the fuel pump will work when I CRANK the car. I tested this by pulling the pump out and holding it in hand when I tuned the key. As soon as I stop cranking the car, the pump looses power. The car will start if I crank it, but as soon as I let go of the key it will stop. So the fuel pump is only getting power when cranking. I have noticed there is no "fuel pump relay" in my car, its missing in the fuse box. I replaced the fuel injection relay. I also tried to jump Fp to B+ with no luck. The only things I have noticed otherwise is that the rear brake lights are not working. The top brake light is, but the left and right are not. Unless they are only supposed to work when the car is running. The car has a remote start on it also, but its been on for years. Please advise. I was told a possible PCM issue by previous owner, but who knows.

hzt30

The fuel pump doesn't necessarily run with the key in the on position. Some models do and some don't.

The starter supplies a signal to the ECM which activates the circuit opening relay. This relay turns on the fuel pump. When the ECM detects a signal from the crank sensor (NE signal) it keeps the fuel pump running. Check to see if you are getting the NE signal.




This is from a 1997 ES300 which is a 1MZ-FE engine:




All brake lights should light regardless if car is running or not.


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gpshogan

Thanks for the reply.

But.

Does anyone know, if on a 95, the Fuel Pump should prime with the Key On?

That would be the first thing I would need to know.

And how can I test the NE signal to the ECU?

If the car wont run, im not sure how to test the signal, unless I can text it when cranking. ANy idea the color of the wire?

hzt30

I asked this question to several Lexus Dealers on a 98 Model and half of them say yes and the other half said no. But they all say that as long as you can turn the key and it starts not to worry about it. My Camry does not prime.

You can test the NE signal by just cranking the engine and using a computer safe test light to see if you are getting pulses. However, if you are getting spark it would indicate that the crank sensor is at least firing the coils.

Did the brake lights stop working at the same time you got this problem?