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Hey guys...i recently purchased a '98 GS4 about 2 months ago. The car was in need of tlc. So i figured i would buy it and bring it back to life. It's high mileage at about 240,000 miles. I dont know the history of the car. I bought it from a shady acting couple. Been replacing things since the day i bought it. Now on to the current issue. Drove it last Wednesday without any issue. Thursday morning i came out to head to work and it wouldn't start. It's trying to crank but wont start. Put the obd2 reader on it and it just gave me the code for o2 sensors. Which i knew the car needed. Replaced the fuel pump and replace the relay. Note: after looking thru the fuses. The car is filled with wrong amp fuses. Meaning it may require a 10 amp but it has a 20 amp in its place. Honestly probably 10+ fuses have the amp fuses in place. Its currently my only car and i really need it back on the road. I've tried to jump the car and it just does the same thing. Thanks in advance for help

vijayn

Judging by the wrong fuses in place, it could be a burnt out wire or a control module power failure. If the engine ECU hasn't got any codes, it may be because the ecu isn't receiving one of the 12V or ground supplies. This is why it hasn't logged any new codes.

I would start by making sure all fuses are all good first and the correct ones are there. Then check on the ecu connectors whether the correct 12V and ground is on the appropriate pins.

Unfortunately I don't have a wiring diagram for a GS400

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That's the plan for tomorrow. Getting all the correct fuses in place. Then start wire chasing

Mr Jokster

iTrader: (8)

You need to start with the fundamentals first. Find out why its not cranking, is it because lack of fuel or lack of spark, then you can go from there.

FrankT

You say it’s cranking but not starting?
So is the starter turning the motor and there is no ignition?

Is there a check engine light on when the key is in the “ON” position?
This will indicate that the ECU has power.

Get those fusses sorted out hopefully that’s your issue.

Good luck.

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Won't be able to touch the car until after work. So far this is all i could have come up with. Some of the fuses need to be change. I thought the fuel pump was the issue. Wasn't that...i changed the pump and relay for the efi. Im not familiar with Toyota/Lexus. I'm a chevy guy...it gave me signs like it wasn't getting fuel. That's why i jumped and replaced the pump. When i put the key in the ignition its turning over like the starter is engaging and thats all i get. I get all the dash lights when i turn the key. So its just a steady cranking and won't catch to start. I have switch some relays out. The car was abused before i got it.

Mr Jokster

iTrader: (8)

Throw some carb cleaner in the TB, or hold a rag over the intake doused in gas. Chevy, Lexus, Hyundai... ALL cars work the same. If the car starts with what I just noted, then you know you've got a fuel problem.

Now don't forget, just because the fuel isnt working, doesn't necessarily mean its a fuel problem. Could also be the anti-theft system malfunctioning... Whats the condition of your key?
obviously anti-theft is worse case scenario...

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The condition of the key is that its an aftermarket one. Like the ones you get from home depot or lowes. Its the only key previous owners gave me.

kevin3344

I think your key can't do the handshake with the ECU...I would get a proper key made from the Lexus dealer and go from there. You will need to provide proof of ownership.

vijayn

Have you checked out the basics as Mr Jokster said? Is there fuel and spark/ignition?
Can you confirm that the pump turns on and delivering fuel when ignition is turned on?
Judging by how the previous owner has changed fuses around I assumed the problem is more likely something has burnt out. But now that you say you have a third party key, this would cause the same issues.
Check to see what happens to the red security light before and after you insert the key to start the engine.

kevin3344

Are you sure you don't have the valet key? It's the one in the center of the photo below. As others have mentioned start with spark/fuel but whatever you do *don't* buy parts hoping you've solved the problem. At that point take it to a reputable Lexus dealer and have them do a diagnostic for $140. Because you'll be going in circles trying to figure it out.

Mr Jokster

iTrader: (8)

Wow, people really ran with the key thing, but you all got it wrong!

OP stated he's driven with the key before, so regardless where it came from, its not the problem; not to mention, its not the actual key that talks to the ecu. The transponder is in the housing which is transferred from key to key. I've been using aftermarket keys for years without fail...

OP, my bad... I meant to ask, whats the condition of the transponder part of the key, not the key itself. Have you by any chance dunked it in water or anything?

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The transponder has never been in water. I take good care of it especially since its the only key i have for the car.

vijayn

The car working and now not working, doesn't mean that it has nothing to do with the immobilizer system though, it could still be a faulty amplifier module, wiring etc that is now not working. Its not only the key that can get faulty. Also the transponder it self can become faulty too. To help confirm this, he can check the status of the red security light. This will confirm that the transponder and amplifier are communicating and the ecu is ready to go.
The sooner you can test all these suggestion OP the clearer the picture we will get.

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Ok guys here's the update. Change a the fuses on the driver side kick panel to the correct ones. Which was probably 3 i didnt have to change. Change all the fuses and relays in front of the battery. Got a fresh battery. On to the key. The red blinks until i put the key in and turn it. The red light goes away. I got full power to everything. I did have one blown fuse. It was to the slot for ECU-IG on the driver side kick panel. I did replace the fuses in that fuse block with the correct ones. One thing i didnt mention before is the car did have what i call a slow crank. Meaning I'll have to hold the key for like 2 seconds. Where normally in other cars its a turn automatically start. Thats how it crank since the day i got it. Thanks for everyone that has been responding. Im used to the impala forum and they are nowhere near as helpful as you guys.