TLE0629

I have a 2000 Lexus LS 400 with about 125,000 miles on it. This past week, each morning when I go out to start the car, its dead - just clicks when I turn it over. Bring out the wifes car and jump it, and everything is back to normal until the next morning. Same thing for the next 4 days. And now, the battery is still dead but when I jump it, it just turns over but does not start. The battery is about 9 months old.

Any ideas of what to check and the order to check them in?

Thanks,

LScowboyLS

I would try the following:

● clean battery terminals and battery posts thoroughly with a wire battery brush (wash hands and clean up area because lead is bad for you!)
● replace the positive battery terminal (these tend to go bad on Toyotas, make sure to use the real Toyota part p/n 90982-05037) -buy at Toyota dealer for better price and request 20-25% discount
● replace the battery - just because the battery is only 9 months old, is no guarantee that it is good, batteries can fail early for any number of reasons, such as a bad alternator, low water, sitting discharged, etc.

TLE0629

So, the engine can still turn over and try to start even though it could still be a bad battery, or a positive cable - battery related? I thought that if the engine turns over and tries to start that it would be something else but I was still curious why the battery is dying.

My older cars I would have said that it would be fuel related but newer cars I do not know. But if the car can turn over and try to start and it could still be battery related, I will give that a try.

Thanks,
Todd

LScowboyLS

if jumping the car cranks it up successfully, then it is not a fuel issue, it is a bad battery or bad battery terminals or bad/dirty battery connections

TLE0629

It jumped before but now it just turns over and does not start when I am trying to jump it. The first four days, it jumped just fine but now it does now. I hook my wife's car up to it, it will turn over and over and over but will not start. I am still curious as to why the battery keeps dying over night but now I believe it will be something else.

So, jumping does not work anymore. It just turns and turns and turns.

LScowboyLS

sounds as though you have a couple of issues in play

if the battery is becoming discharged, then you have a drain or a bad alternator or just a bad battery

if the car will not start with a known good charged up battery, then you need to perform a few tests:

● did you blow a main fuse or other critical fuse by this jump starting (jump starting is not a good plan on modern cars)

● have you somehow invoked the cars theft deterrent system accidentally with this jump starting business?

● have you scanned the car for diagnostic codes using an OBD-II scanner like this one?

● have you pulled all 8 plugs to see if they are wet with fuel or not after a cranking attempt? (the reason to pull all 8 - one at a time - is to look for patterns, some wet and some dry)

● have you checked the fuel pressure with a tester like this one

● have you disconnected each plug wire and rested it on the engine (one at a time) and verified a spark jump (best to do this at night)

● if you have wet plugs and a spark jump at each plug, then the issue is likely either ECU, one of the cam sensors, the crank sensor, wiring for one of those sensors, or jumped timing belt

BdBlkSC400

Sounds just like a blown main fuse, the fuse issue happened to me once bout a yr ago, popped a new n, been gud evry since!

TLE0629

Blown Main Fuse? is that with all the other fuses?

I have an OBD II connected to Bluetooth using Torque but it does not give any codes.

After checking main fuse, I will check the wires. I forgot to mention that I live in Colorado and it was about 10 degrees at night this past week if that makes any difference.

LScowboyLS

check the critical fuses (the large ones in the engine compartment)

TLE0629

I see big block fuses (I assume) in the main compartment then I see fuses closer to the engine that contain a 120A Alt, 80A Main but not sure how to get those out to test. In the main compartment I see a big block that says Engine Main but again, not sure how to get out. The big block appears to have tabs on all four sides. The 120A and 80A I cannot remove from the top so I'm assuming they are attached to the bottom somehow.

I went and bought a new battery and now will be driving to pick up a battery terminal. When I get back, I will see if there is a way to get these fuses out and how to test them.

Thanks again

roadcar

roadcar,TLE0629 I had a similar problem with my ls400 the nuts on bolts in the terminals needed thiten

TLE0629

Update -

I replaced the battery. I replaced the positive battery terminal (90982-05035 - updated model with a plastic piece to protect against corrosion). Now the car will turn over on its own. However, it will still not start.

The fuses are all good.

It's dark out here so I will check the plug wires tomorrow.

The dealership told me to hold down the gas pedal and turn the car on and see what happens. I did that, held the gas pedal down, turned the car over and held it over. It started for a split second and then immediately died. I did the same process again and it sounds like it wants to start but will not again.

So, it does sound gas related to me (a complete novice). As stated prior, I will check the wires tomorrow when I have more light. If not, it sounds like I'll have to have it towed unless there is something I missed.

Thanks again for all your help.

LScowboyLS

don't have it towed! - that's not the spirit! - do the tests i outlined in post #6

TLE0629

With a computer on board, why wouldn't the car be throwing a fault code at me telling me what exactly is wrong. The car won't start so my thinking there should be a code. If the engine is not getting any gas, then there should be a gas code. But there is no check engine light on.

LScowboyLS - the fuel pressure kit lists GM/Chrylser/Ford but will it work for Lexus? And where does that hook up?

Could it also be something with the ignition coil? If so, is there a way to test?

LScowboyLS

the fuel pressure tester i linked to has the special banjo bolts for Toyota

if the ECU itself is bad (I.e. capacitors) then it often won't throw any code at all

and yes, it could be an ignition coil, have you verified that it's firing with the tests I described in post #6?