1991 Lexus LS 400 - Page 3 - Answered Questions & Fixed issues

It is simple and complicated at the same time; do not do it by yourself since you may brake the fuel line and it will need to be replaced entirely. My advice is, go to the dealer, it pays to have peace in mind

1991 Lexus LS... | Answered on Apr 03, 2014 | 50 views

I don't know about back seat access, but you may have a feasible idea about the 12volts -maybe. Does your vehicle have a button on the dash to pop the trunk?? If so, that button works with the ignition switch in the 'on' position. Obviously you can't use the button since you can't turn the ignition to on. However, if you can get to the contacts of that button, you may be able to energize the trunk opener. Hopefully there are only two wires on that button switch, which will simplify matters. If you take a wire from the Positive battery terminal to the button switch, you may be able to energize the opener. If it's a two terminal switch, one side or terminal is power (12v) in, and the other terminal is 12v out. If you put 12v to one terminal and nothing happens, push the button. Can you pop the hood to get to the battery???? If not any 12v battery can work, lawn mower battery, etc. : Negative terminal of battery to car frame, positive to switch. This would be a low current draw, so the wire can be anything like speaker wire. Since the wire is live, just be careful not to have it touch any other bare wire connections or part of the frame, etc.If this works, it will probably set off the alarm, since the ignition switch is off. I really don't know if this will work, but if I was in this dilemma, I would try it. After all said and done, someone might be able to tell you how to access the trunk by way of the back seat. GOOD LUCK!!!!!!!!!!

1991 Lexus LS... | Answered on Mar 30, 2014 | 139 views

run fault codes as it is controlled by the TCM

1991 Lexus LS... | Answered on Feb 19, 2014 | 18 views

Check your MAF and MAP sensor. The first 80% of your throttle signal from the TPS works with the O2 sensor to try to keep the air fuel ratio to 14.7 to 1 with the ECM controlling the fuel injector spray time and timing the ignition. After the 80% to WOT the ECM puts the O2 sensor in to an open loop and takes the Reading form the MAF and MAP sensor to run the engine richer so there will not be any Detonation to the engine and burning holes in the valves for running too lean. That is why it always feel like you get a little more when you ease off on the gas peddle from WOT. Recap check the TPS, MAF,and MAP sensor and wires to those sensors, if you can get the car scanned that would be great and you may find out which sensor may have gone bad, the other thing to is the fuel pressure regulator may be going bad and at WOT the pressure may be to high causing it to run to rich causing the loss of power. Good luck and hope this helps. 

1991 Lexus LS... | Answered on May 23, 2014 | 1,732 views

be a fuse or relay or the switch..

1991 Lexus LS... | Answered on Dec 27, 2013 | 35 views

NOTE: C means "to coil"


1991 Lexus LS... | Answered on Dec 09, 2013 | 48 views

fuel pump relay failing when gets hot .solder cracks open up when hot .and close when cold.

1991 Lexus LS... | Answered on Dec 06, 2013 | 45 views

try your fuel pressure regulator.some time it can get damaged when there is no fuel in the system. may have stuck shut.

1991 Lexus LS... | Answered on Sep 26, 2013 | 490 views

look for external leaks, if none apperent check for injectors leaking

1991 Lexus LS... | Answered on Sep 03, 2013 | 105 views

As mentioned check ps fluid. If it wines when turning and still no power then the pump is internally bad.. If the fluid is dissapearing fast then its a hose or most likely a leaking rack& pinion assembly..

1991 Lexus LS... | Answered on Jul 07, 2013 | 958 views

The large part of the cable goes to the post on the starter. The smaller wires go to various connections including the main fuse box.

1991 Lexus LS... | Answered on Jun 20, 2013 | 57 views

is it a digital odometer the back light on the lcd may have burned out but the odometer is still working you just cant see it unless you look very carefully and in proper lighting to fix it you would have to replace the dash panel gauges

1991 Lexus LS... | Answered on Jun 03, 2013 | 360 views

if your talking about thew gas gauge it is in the tank.

1991 Lexus LS... | Answered on May 21, 2013 | 441 views

There is 2 possiblities. 1 there is a speed sensor on the side of the transmission ( I'm not 100% where it's located) that has a plastic gear attached to main shaft in the transmission and it is not making good contact with the shaft. 2 The wire harness connected to the sensor may have a break in the wire.

1991 Lexus LS... | Answered on Apr 23, 2013 | 346 views

IS the battery original spec? the amount of electrics on these cars is huge and hence the original battery being the size of a trucks. LS does take a 27F Battery and it is 710 CCA

Check boot lights are switched off.
Ensure you lock the vehicle when leaving it too, this activates "Sleep mode" and the car shuts everything down.

1991 Lexus LS... | Answered on Apr 12, 2013 | 62 views

What is the light on my lexus ls400 that looks some what like a dome what does it mean

1991 Lexus LS... | Answered on Feb 26, 2013 | 1,052 views

maybe the rack&pinon

1991 Lexus LS... | Answered on Jan 18, 2013 | 55 views

Probably time for a new battery.

1991 Lexus LS... | Answered on Dec 30, 2012 | 265 views

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