MikeTN

First post, so be gentle.

My wife's 2004 RX330 has over 225K miles, does not burn oil and gets 27+ mpg on highway. I've taken pretty good care of this car. This morning the battery was dead. This has happened before. I have replaced the alternator and battery a couple of times over the past years. I checked the voltage on the dead battery -> 9.8v, got my charger, gave her the keys to MY Truck so she could go to work (somebody has to keep me in the lap of luxury). I let the battery charge for 2 hours and with a spare "boat" deep cycle (#29) battery tried to jump start her car.
It didn't start. Engines spins, tries to start, but doesn't.

Battery seems to take the charge just fine. Voltage after charging is 12v+.
What drained the battery and is preventing engine from starting?
Bad fuel pump? If so, how do I verify this?

Any suggestions?

Mesquite77

You can search for "crank, no start" to get a lot of info, but when I had a similar problem and I suspected the fuel pump, it was impossible to hear from inside the car. You have to open the gas filler cap, and put your ear to it and then crank to see if the fuel pump primes. Lot of possibilities, anti-theft (engine cranks, no fire), no spark, etc....

In the end, my issue was so many leaves in drains at bottom of windshield, water must have gotten on some connections (crank no start after a big rainstorm), because after it dried out, its been fine for 6 months, despite all the hose soakings I gave it trying to reproduce the problem.

Audiqv8

In order to correctly test a battery, it must be placed under load. You will need a battery tester that can place about 100 amps load and the voltage shouldn't go below 10 volts. You can also take a fully charged battery to your local auto part store and they will test it for free. Your fuel pump is controlled by a relay. When you turn the key the pump will run for a couple of seconds but will stop if the ECU doesn't see a certain RPM signal from the engine. You should be able to hear the fuel pump when you first turn the key to the ON position. Unless the fuel pump relay is stuck, I doubt that this is the cause of your battery drain.

MikeTN

Mes-77 : I believe the car is firing. When attempting to start, the engine sputters, tries to "catch", but fails -> almost like it is not getting any fuel. I will check the fuses and listen for the fuel pump and report back.
Aud-8 : Yes I do know to perform a proper test of a battery, but a weak battery will allow the car to run with a working alternator and vice-versa.

Not sure what drained the battery overnight, but I am assuming whatever it was that drained the battery is tied to the non-start issue. Here again, there may be more than one issue

MikeTN

Okay asked a friend to start the car while I stuck my ear to the fuel fill nozzle. I could hear the fuel pump operating during start. ENgine still didn't fire off. It sputtered, I pressed the accelerator pedal down a bit, nada.

Since the car operated flawlessly last night and had a dead battery this morning, could an ECU fail and cause a drain on the battery?

Any ideas on what I am chasing?

Audiqv8

The Good News is that the wiring to the fuel pump is OK. Even though the pump is running still doesn't eliminate it as a problem. It could be running, but the pressure is not high enough, only a pressure test will confirm or eliminate the fuel pump as the problem. Do you have enough gas? I know that it might be a stupid question, but I got to ask. Do you have a code reader? Is there any code(s)? How old is the battery? You have a drive by wire throttle which means there is no cable between the gas pedal and throttle. Your car does not completely shut down when you turn the key off. There are systems that can stay active for up to 15 minutes and part of the evap. system will turn itself on hours after you have turned off the car. I would suggest that you take the battery to a local auto part store and have it tested.

MikeTN

Thanks for the quick response. I found the issue, blown fuse to the throttle control and a weak battery. New battery installed, fuse replaced and she smoked like the devil. Idling a bit slow, so I did a throttle bottle clean and she perked right up.
I didn't have an OBD tester so I old schooled it just by eliminating fuel first (I borrowed a fuel pressure gage)and started down the "fire" paths. Felt real dumb when I found a blown fuse, but hey, I've felt that before.
Thanks again Guys......

Audiqv8

Glad to hear that you got the car running. I think that you might have found your battery drain. The fuse for the throttle control. You need to look into that circuit to see what else might be on it. Fuse does not normally blow unless too much current is being drawn. Good Luck....

toantran99

My LS430 was doing the same thing, turn out it was a bad fuel pump