Great info.

As seen in this example, with that circuit diagram, it's difficult / futile / maybe dangerous to try to troubleshoot systems like this without getting and understanding the correct circuit diagram. Also note that they made many subtle (but important) changes throughout the years, so make sure the diagram you find is correct for your car.

 

High Clarity. Look at those Wheels.


I think the bubbling is somewhere in this picture.

Going out to pick up this beauty on Wednesday. May the Lexus gods smile upon me. I edited these pictures to highlight imperfections but can't find many.

 

Looks like cypress.color interior. What is condition of your seats?

 

I just pick up the starting fluid part to inform you where and when to spray. Two red arrows show points to spray. Either will do but the left smaller one would be easier. Remove the hose and spray the fluid to the hole of the resonator box side. The timing to spray is a bit after the engine is started and spray continuously. If the engine can't start easily, start spraying just before starting and spray continuously. When you stop spraying, the engine should be stopping within a few to several seconds if the gasoline is not supplied by the fuel pump. You can use a can of parts cleaner instead of a starting fluid, I must add. It costs only a couple of dollars or less and you can use it without spending big money. Hope this helps.

 

The seats are in good condition. I'm not sure on the color. The front seats look green to me but the back seats look grey. After I increased the color you can tell a bit more. They really look like different colors to me but that must be the light playing tricks.


Grey?

Green?

 

It does help thank you. I still don't really understand how the starting fluid will diagnose this situation. If the engine will run for a couple minutes and then die how will starting fluid help? If the car start and runs for 240 seconds, how is keeping it going for 5 more seconds with starter fluid going to show me anything? Or how does using starting fluid during the beginning of the 240 seconds show me anything. If I use the fluid and it still dies at 240 seconds what have I learned? Or is it more for if the engine won't start at all? I know I am trying to diagnose an issue with the fuel system. Thank you.

 

The word starting must be confusing you. What I mean here is not to start but to keep the engine running. If the engine stops after 240 seconds, spray the parts cleaner 230 seconds after the engine is started. If this prevents the engine going to stop, it will simply mean that you have the fuel supply problem. In other words, to spray parts cleaner to the hole is to supply fuel via the throttle body to cylinders not via injectors. Parts cleaners evaporate very quickly and you just need to spray it to the resonator which is the big black box and is ahead of the throttle valve.

 

That is pretty much what I was thinking you meant, thanks. I have talked to the seller on the phone, he gave me a bit more information. I mentioned to him that it could be a fuel pump issue. He was adamant this was not the cause, he seems like at least a DIY'er level Mechanic, he says electrical for sure. This is what he told me. "The car will start and run. Around the 3-5 minute mark the instrument panel goes crazy, the car shuts off, and then begins to crank on its own for a while."

 

Call me crazy, it's accurate, but I'm still struggling to understand why you're trying to buy a car you can't even test drive...?

 

Ideally she will get a long test drive tomorrow. I saw an old post that said I should do it.

 

The new information above is something very important. The words "the instrument panel goes crazy" must be the key to troubleshoot to me. How does it go crazy?

Blinking?
Flickering?
Turning on many lights?
Meter needles dance?
Others?

I need to know the detail of it. Depending on the situation, I'll monitor the voltages. I mean to measure the supply voltage 12V+ from the alternator and regulated 5V inside of the cluster unit.

 

I should have asked about it in more detail. Now that you mention it he said it turned on all the lights. I thought he meant lights in the instrument panel. He specifically said turns on the lights. I would assume its all of the above but he did not mention anything else. Other then the dying and cranking on its own. When he said "instrument panel goes crazy" i did feel/think he meant blinking/flickering and needles moving.

The seller was sure I have no chance of figuring it out with simple troubleshooting. He says its an electrical issue but you need the wiring diagram and need to go 1 by 1 searching for the root of the problem.

 

I'm also paying an attention on "cranking on its own" and this is quite strange. The cranking needs to turn on the starter relay by the ignition switch using your hand. These are the only devices to turn the starter on. But what happens if the NSS (Neutral Safety Switch) / (Neutral Position switch) is leaky inside? The NSS has thick copper contacts inside and it is often filled with copper dusts when aged. Those dusts may cause the current leaking path.

There is a fuse 7.5A Starter and a NSS (Neutral Safety Switch) between the +B 12V and the starter. I worry that the NSS has some leaking problem inside. The NSS is also supplied the +B 12V from the Fuse 10A Meter(Gauge) which is used to supply the power to the backup lights and others.

This is only my guess without seeing the car myself and I don't have enough confidence but I imagine that the copper dusts in the NSS are making a current path and semi short-circuiting between +B 12V and the starter relay line with some resistance. Without turning on the ignition switch, the current path may drive the starter relay.

Other than the starter relay and the ignition switch, a leaking NSS might crank the starter If the +B 12V were leaking badly to the starter relay line. This happens when Pin#4 and #5 of NSS is bridged by the copper dusts. The reason why it happens 3-5 minutes after started is that the battery is getting charged enough and +B 12V becomes high to supply enough current and drive the starter relay.

The confirmation can be done removing the "fuse 10A Meter" right after the engine is started and running. The Fuse10A Meter also supplies +B 12V to the cluster unit and the voltage drop may cause the problem "instrument panel goes crazy", I imagine. What happens if it is removed. No more crazy instrument panel nor strange cranking?

I hope you understand what I write. English is not my mother tongue and I still have difficulties to write.

 

I think I 'd better to add some more for your better understandings. Below is the starter circuits. You can see how the fuse 7.5A Starter and a NSS (Neutral Safety/Position Switch) are connected. The red arrow shows the pin #5 of the NSS line. If the line is supplied +B 12V, the starter relay will be activated and the starter will work. Usually the ignition switch do so via the NSS.



--------------------------------------------------------------------------------------------------------------------------------------------------------------------
The wiring diagram below is about the backup lights circuit. The red arrow shows the fuse 10A Meter/Gauge line connected to the pin #4 of the NSS.
If the pin #5 and #4 are semi-conductive in the NSS due to the copper dusts, there goes some current. If the current is enough to drive the starter relay, the starter will work.


------------------------------------------------------------------------------------------------------------------------------------------------------
Below is the part of the cluster unit. See the fuse. It is 10A Meter/Gauge. This line is common to the pin #4 of the NSS. If there were the enough current leakage between pin#5 and #4, the starter would work as well as the cluster would get lower voltage to go crazy.


If the car were repaired only replacing or cleaning the NSS, it would be a very good buy.
The pin#5 and #4 are next each other and also those contacts are long. Accumulated copper dusts may cause a problem, I imagine.

 

Thank you Yamae. I really appreciate all your effort here. Your English is very good thank you. But, hypothetically, if you are correct, the 7.5a or 10a fuse could be disconnected once the car has been started and the NSS will no longer receive power and the issue could be gone long enough to make it home.(Without the instrument cluster display) I imagine the 7.5a and 10a fuse's in the diagram are not in the fuse box but part of the electrical system? Or would I get lucky and they are easy to access? Or can the car not be driven without the NSS?

I am hoping that reseting the ECU will make the problem go away long enough to make it home. If I can disconnect some fuses and make the problem go away to get home great. Whatever works.

Also my plans have changed. I am now going to go on Monday to pick up this girl so I have more time to learn.


Edit: Searching the forums I find this NSS Thread
and the first post by oldskewel relates to the 7.5a fuse. Driver foot well box. Its a different problem as this thread is about a car that will not start. Thank you again Yamae.