PPOIII

1991 LX400.

I have posted this problem before. I have checked all fuses circuit breakers,and yes the ones under the hood. I know this car is notorius for shorting out at the front power point which is on his same circuit. Supposedly just loose change in the ash tray has shorted out this circuit.

I have exhausted all my knowledge and cant afford to get the mmanuals. So I am about to drive 300 miles to see a friend who is a wizard at this stuff, and also my old Lexus Mechanic has his own shop in Conroe Tx. So I have a trouble shotter at my disposable.

Any of my Lexus friends out there know anyore ideas? Before I make a 600 mile trip. I need this car fixed and fast. My wife is going to have to have to drive this car and soon. But not without heat, air radio, mirrors etc. MAYDAY

Paul Ontiveros

In the same drivers side kick panel fuse boxthere are 3 circuit breakers above the fuses one of which may have tripped.

To reset make sure the ignition is off then carefully insert a thin object such as a toothpick, needle or safety pin into the hole on top of the breaker,gently push until you hear a click this means it has been reset.

Turn on the ignition and see if the applications affected now operate,if they do you're done but if the breaker trips again you will have to delve further into the wiring loom.

Steve I tried to reset the breakers with no sucsess. I think I am screwed!!!!!!!!!!!!!!

Ok Lexus pals. Here is my next problem on my 91 LS 400. My side mirrors,radio, AC are out. I know its all on the same fuse. I have tested the fuse. It is hot on both sides which means the problem is beyond the fuse box. Has anyone out there traced down a short in the dash like this before? If so how hard is it?

Come on Andy what do you think?

You are batting a 1000 so far!

Thanks, Paul

I once bought a truck that would indicate it was low on fuel.

The gauge made me think it needed to be filled up, when all the while, it was tricking me!

I suspect your Fuel Gauge is indicating incorrectly, and you "think" you need to fill up, and when the overflow occurs, you "think" your tank is unable to vent.

Because you have a 1991, I highly suspect your Fuel Pump SENDING UNIT, the variable resistor which is attached to a swing arm with a float on the end, is defective.

My 1994 LS400 has access to this pump and sending unit, by removing the rear seat cushion first, followed by the rear seat back.

Next you will see an access panel, with screws holding it onto the sheet metal where the seat back was. Removing it will allow access to the pump and sending unit.

Because I think your tank is VERY full, I would first drive it at least 200 miles, and then gain access.

You can purchase a subscription to www.alldatadiy.com, for a 1 year period, and have access to all kinds of good service manual info.

My 1994 LS400 has a solenoid valve, that is located on the driver's side, inner fender, down low. A single vacuum hose connects to this valve, and this rubber hose then attaches to the front top edge of the Intake Manifold. Only when the Computer commands this valve, does gasoline vapors from the tank, enter the Intake Manifold.

A blocked vent line, under the car on the driver's side would NOT cause the engine to die at idle. You should look for other causes of poor idle. It's likely a coincidence that filling up, and dying at idle occur.

Gas Caps are bi-directional and SHOULD allow air to enter the tank, when displacement is necessary; ie,,, you're using gas out of the tank, air needs to enter.

Does your tank suck air in when you open the cap? Replace it.

It would be nice to know your tank is not the problem, rather your Sending Unit, the item that tells your Fuel Gauge what to indicate.

When I worked on Audi's, it WAS the tank.........! I don't have nice things to say about Audis.

Best of luck,

Andy

Andy well you have been just about dead on. Turns out there was alot of gas in the tank. I pulled the rear cap off the tank and it was over half full. There is a float that we tapped a bit an reinstalled and my gauge came back up to about 3/4 after filling the tank. Now the idle problem was the idle air control motor. Just a coincidence it was dying after fueling.

I took it apart cleaned it up now its running perfect.

Now I have a problem with my radio air and mirrors not working . There is one fuse for this, but it is hot. So now I have no idea where the problem is.

What do you think?

Thanks, Paul

Ok I am not getting many answers on my fuel tank problem. Is there anyone who can tell me where the fuel tank canister vent is located? I'm almost sure this is my problem and I a hoping I dont have to drop the fuel tank itself to get to it.

Thanks. Paul

I have a 91 Lexus LS400. It will only hold about 6-8 gallons. It will often stop running at idle after putting fuel in it. And lately it burbed a ton of fuel out when my wife went to fill up. I think it is a vent valve problem.

My qustion how do you drop the tank on this car and get to the vent valve.

PLEASE HELP

Manuals are 186-200 bucks. I can do the repairs just need to have good material or instructions.

Thanks Paul.

You mean you cant even fill it full if you slowly pump gas into the tank?

Nope we have tried everything. Pumping slow, turning the handle around. You cant fill it up. Then it dies after fueling and the gas gauge is not accurate.

I have a 91 Lexus LS400. It will only hold about 6-8 gallons. It will often stop running at idle after putting fuel in it. And lately it burbed a ton of fuel out when my wife went to fill up. I think it is a vent valve problem.

My qustion how do you drop the tank on this car and get to the vent valve.

PLEASE HELP

Manuals are 186-200 bucks. I can do the repairs just need to have good material or instructions.

Thanks Paul.