adrenelin5

I just had a look at the video. Believe me it's in the correct position. I've had that off oh about a half dozen times in the last week. It's seared into my brain.

LScowboyLS

notice how the top part of the belt routing is running counterclickwise, just like the fan is - that is not correct

they should be going in opposite directions

fan should turn counter-clockwise (and it is), but top of belt routing should be moving left to right! - look again


- like this:



the part of the belt near the guy's thumb in the middle should not be going in the same direction as the fan, and it sure seems to be in that first cranking video

adrenelin5

The diagram is correct before the x's were added. If you turn the crank clockwise by hand it would make the belt go clockwise and the fan go counter clockwise. From what I can see i the vid it's loks to be doing just that.

LScowboyLS

I guess it is just some weird strobe effect that makes the top part of the belt seem to be going counterclockwise in the video - strange!

like when you stare at a fan blade and it seems to be going backwards

Brutuz

My LS400 wont start in the morning when it is too cold. All dashboard lights are on but no click sound - as if a starter is not connected. But after 10AM with the sunlight is up the starter works perfectly. This starter was replaced 3 years ago. The battery and alternator are in good condition. Do I have a problem with moisture?

c50sooner

LS you were right on with your recommendation to just keep trying to get it to catch.

I used some starting fluid and cranked for what seemed like forever with the gas pedal a little down, and eventually it briefly clumsily stuttered to life. Now it starts right up very easily, but it immediately dies. The video below shows what it's doing now:

http://youtu.be/2-TgTsnTULk

Just verified with OBD2 there are no current, pending, or historic fault codes.

Any ideas what to try next?

LScowboyLS

the first thing I would do is scan DTC trouble codes, write down which ones are stored, then clear DTC trouble codes, then crank and run engine as long as you can with your foot holding up idle , then rescan for codes that come back

at this point a primary suspect would be something in the fuel control circuit

fuel pump
fuel pump relay
circuit opening relay
fuel pump resistor
ECU
wiring between ECU and ground
wiring between fuel pump relay and fuel pump
wiring between fuel pump and ground


another possibility is a very large vacuum leak

and there are many more possibilities, but nothing that can't be tracked down by someone persistent!

get the codes!

Yamae

I worry about the incident below.
You wrote,"cables loose." Do you mean both "+" and "-" cables? Or just only one side cable?

The reason why I ask you is that there often happens a problem called a fly-back pulse generation when the battery cable of "+" side is loose and this damages electronics circuits.

I worry about that this might be causing your problem now.

LScowboyLS

this sounds very interesting, please give us an education, Master Yamae

Yamae

My limited English would not be good enough to explain this but I will try.
The voltage of the fly-back pulse "e" is explained by a physical law below.

e＝－L di/dt

"L" means the inductance of the circuit, "di" the differential calculus of the current, "dt" differential calculus of the time.

There are different inductive equipments connected to the battery. The starter motor is one of them and ignition coils are quite inductive too. When the current to the inductive equipments is stopped, there appears a fly-back pulse which is much higher than the battery voltage.

Simply to say, the bigger the "L", the bigger the current is and / or the shorter the time, the generated fly-back pulse is higher and sometimes this is enough to damage or kill semiconductors at the circuits connected to the battery line.

Since the connection is loose and when the starter motor is energized, some vibration might cause the connection and disconnection at the battery terminal. This switching generates the fly-back pulse at the battery cable. It goes to many different equipments connected to that line. The radio, the alternator, the ECU and many other equipments are connected and they are stressed by the fly-back pulse.

Toyota uses a device called a Varistor which absorbs the fly-back pulse. But it delays to start to work and it is not 100% effective. Repetitions of the switching sometimes cause problem. I worry about this has happened to the car.

As is written at the middle part of below page, disconnecting a battery while the engine is running can destroy sensitive electronic components or the charging system because the peak voltage can rise to 40 volts or more.
http://www.supercharge.com.au/battery_care_4.php
"Test the alternator by disconnecting the battery with the engine running"

LScowboyLS

Whoa!

python

iTrader: (4)

definetly a fuel issue...i would see if ur getting power to ur pump with the key in the on position and/or during cranking
if u r getting power u need to see if u have fuel pressure..if not check ur relay or next point of power..working backwards

c50sooner

Yamae, thanks very much for that information. Not every day that we get a response in di/dt calculus terms!

I too was worried that the loose cables had done some electrical damage. To the best of my memory, the ground cable was the looser of the two, but I could easily move both of them (the tech had coated the entire battery area in spray lube). I don't believe either cable ever came all the way off, but certainly could have been loose enough to intermittently disrupt current.

Since the symptoms currently point to the fuel system, I'll plan to start with the fuel pump relay.

Also, still have no engine fault codes.

Question though, if it was a failed fuel pump relay, or fuel pump, would that keep the engine from getting enough fuel during the cranking to keep successfully starting? Seems like if it was just a bad pump, it wouldn't get any fuel at all and would not be able to start it each time. Perhaps the cranking of the engine provides enough pressure to draw fuel? I seem to remember reading that the LS400 fuel pump doesn't kick on when you move the key to "on" like other newer cars (I know that you hear no fuel pump operation in "on" position, and people have blamed long cranking time to start on this design).

Yamae

Judging from the symptoms, the engine starts nicely but it stops right after that. I think I can provide you some more information regarding this area. Below is the circuit diagram of the area.


You can see how the 12V DC is supplied to the fuel pump. The fuel pump receives 12V via 3 relays or 2 relays + a resistor.

When at the engine start, the blue line is short-circuited by the Fuel Pump Relay and 3 relays are all closed. This supplies full 12V is to the Fuel Pump . After the engine is started, the Fuel Pump Relay opens but the 12V is supplied via the Fuel Pump Resistor . In this mode the voltage is lowered by the resistor because the high fuel pressure for the start up is not needed. In this mode 4-8 V is observed at the terminal 2 of the resistor.

Your problem must be caused by the malfunction of the Circuit Opening Relay or the opening of the Fuel Pump Resistor . In case of the malfunction, you need to check the ECU. The Circuit Opening Relay is controlled by the ECU signal "FC" which stands for "Fuel Cut ." This works when something unusual is detected by the ECU. If the Circuit Opening Relay stay closed, you need to check the Fuel Pump Resistor .

Thus there are 2 major items that stop the DC supply to the Fuel Pump. I suggest you to check above 2 items first and inform me your investigation results.

LScowboyLS

great minds apparently think alike