91LS400pilot

Probably your alternator is gone due to PS leaking pump. Check that out too.

Hi I have a 94 LS400 with 96400 miles. I had felt a pull with the engine during acceleration and at idle. Thought it might be a transmission problem so I changed the fluid and filter. When we put it in to idle to shift we noticed sparking from the driver side coil and arcing to the engine coolant valve. Now the engine is missing and when I accelerate the transmission is not engaging. Is this a new coil, plugs, wires issue with the sparking? And is this maybe low ATF Fluid for the transmisson? Any help would be wonderful! Thanks!!!!

I had a similar problem. It was the left coil (driver's side) wire. Open the hood when engine is running in a dark environment and check for any fire works.

Good luck

Didnt get it changed today... my dad decided this morning he had to use the ramps to take out his clutch on his 69' Camaro to replace it, so I have been delayed a couple of days. <_< Hopefully will get it changed Monday evening or Tuesday.

THEN onto working on the PS pump.... or should I say change it.

Did you change the tran mount? Any pics?

Hi all,

Can anyone tell me how to apply seafoam to clean the car (intake I'm assuming?) There is a vacum hose that it needs to be sucked through right? And it is the whole bottle?

Try this, very informative.

http://us.lexusownersclub.com/forums/index...;hl=white+smoke

OK then I think the IACV investigation is a red herring then. It only impact engine while idling and if you can't get engine to run at more open throttle it isn't IACV to blame.

Since you don't have ECU codes it doesn't sound like a sensor problem as the ECU should be able to diagnose that so rule out MAF, temp sensor, throttle position sensor, ... for now.

So what's left;

1) Fuel system. Well your 2.5 gallon test seems to prove that fuel filters and fuel pump aren't plugged or you wouldn't have good flow. What you don't know is if the fuel gets to the proper pressure (pressure regulator faulty or pump worn and can't get to pressure level. If you have a fuel pressure gauge or could borrow one from an auto parts store you could double check pressure of fuel to rule out this leg.

2) Injectors. Could be faulty but given an eight cylinder engine one faulty injector wouldn't cause the dramatic performance you are seeing. Seems highly unlikely more that one would fail at a time.

3) Ignition. These cars are know to have problems with dual banks of distributors where one side can fail causing a loss of 4 cylinders. Could be faulty coil, frayed and shorting wiring to chassis/block. Why not disconnect one coil and start. If runs rough but similar (IE no worse) to before then reconnect and disconnect other side. if won't start at all then maybe first bank is dead (or vice versa) for either of coil, wiring, rotor, ....

4) ECU. You've confirmed ECU is functioning although can't tell if 100%. I guess an output could be dead but seems less likely.

5) Wiring. Harnesses with broken wires or corroded connectors. Could be a root cause for (3) above.

Well I got up with a game plan today to go deep into this problem and hopefully fix it. I changed the MAF Sensor, (again) TPS, COIL, IACV, ECM, fuel pressure regulator, secondary TPS, hoses, wirings, etc, etc, etc. I did all the possible fault isolation I could think of and nothing did the trick. After tricking the fuel system I changed the fuel pump and the car is back in business. So now the car is working fine again but I have all these LS400 parts in my garage, all of which works fine but none of which can be returned. I may open a used parts store until I can get rid of them. Thanks for the assistance all, CuriousB you devotion to helping others here is note worthy and I appreciate you time. I have plenty of troubleshooting steps and maintenance for the 91 LS400 in pdf file format if anyone need some information.

I am glad you finally found the problem. Why not attach the PDF in your next posting?

I searched in the old topics and found a few answers, but wanted to verify my findings

I have a 90 LS400 and the speedometer is erratic. It will simply sit on zero for a while, then might register correctly for a few miles. then register 140mph :o When it is eratic, the cruise control does not work, but if it is accurate (rarely) it does

I read that the speed sensors are prone to go bad, and found one (#89411-50010) for $72.00. Does this sound like what I need?

Thanks

Read this:

http://www.clublexus.com/forums/ls400/2259...s-not-work.html

Well, how does one remove the throttle body on these cars? Are there instructions here somewhere? I know nothing about them. I am a fool.

I found what to USE to clean it, but not how to clean it. What all comes off... any special tools?

Also, how do you clean the EGR valve?

Pay a visit:

http://www.lexls.com/tutorials/EFI/throttlebody.html

http://www.lextreme.com/tb.htm

Thanks for the links. Good write-ups. Looks like a fun job. Looks more involved than I thought, but this is coming from someone thats not a DIYER. <_<

I will give it a whirl though.... whats the worst that can happen.... I break a $500 part?

I have done it myself. I am not mechanically inclined and I had put the screws in distinct places to remember the way going back. Up until I joined the forum very recently the dealer was always getting my repairs/maintenance money. I do though have another two cars, IS250 AWD and GS350 AWD. Eventually, I can not beat the system but as far as the old lady she will get my love and tender as far as I can in my garage.

Good luck.

Well, how does one remove the throttle body on these cars? Are there instructions here somewhere? I know nothing about them. I am a fool.

I found what to USE to clean it, but not how to clean it. What all comes off... any special tools?

Also, how do you clean the EGR valve?

Pay a visit:

http://www.lexls.com/tutorials/EFI/throttlebody.html

http://www.lextreme.com/tb.htm

Then you have to find why it’s dragging. The point for BIGAIR64 was to see if it was a dragging brake or some type of problem in bearing. Brake will be hot bearing won't be.

If you have noticeably warm brake on one side then the rotor will likely warp if you don't fix it (not to mention lousy gas mileage you must be getting). It could be stuck piston in caliper (won't release properly) or it could be a master cylinder issue like it sounds could be the case with OP. My bet is sticky caliper as most likely cause. Simple fix is to buy a new caliper and bleed brakes. If you're more adventurous get a caliper repair kit and remove pistons clean it all up and reinstall pistons with new seals and boots. Replace pistons if they are scared or nicked (binding).

Thank you, now I got a project.

Best

Chris

I think oldskewels releasing the bleed valve is a great test to perform next time it happens. Also if you detect it happening check the temp of the wheel and rotor (don't touch it just move hand close) and feel for heat. If the brake is really dragging that one wheel will be much hotter than the rest.

Then what? What's next?

I do not have any brake problems so far but I noticed one day after a short trip when I cleaned the wheels the left front was really hot but not the right.

I had very rough idle at traffic lights and stop signs, hesitation, pushing the gas pedal and engine was dying. The problem was a short on the driver's side coil wire. Black electrician tape eliminated the problem. If the car is in the carage open the hood and see for any fireworks in the engine.

Just my two cents.

Good luck

Forgot to add my 0.2 cents

That's really a good one :D :D :D :D

Regards from Darien

That dark ring/band is a little concerning. It looks like a portion of the rotor overheating rather than even heat across the entire cross section. Maybe just the photo and lighting. If you have plenty of pad left, no shimmy when you brake, and feel there is no appreciable drag when the brakes are not depressed then I guess no worry.

The ring/band is there, it is not the photo, that's why I posted the pictures.

What is approximately the minimum pad thikness?

Thanks,

My last complete brake job (four wheel pads, silencers and rotors resurface) was done by the dealer for $657.28 in 4/24/01-100,872 miles. During one of the routine oil changes in 04/03/04-116,228 miles I asked the dealer to check the brakes too. He said the pads had still another 75% life. Now at 130,000 I do not have any brake problems yet but I try to be pro-active.

Do you see any signs for any repairs?

Left Front

Right Front

Check this:

http://www.clublexus.com/forums/ls400-foru...r-steering.html

I understand from where you are coming from. I have replaced my alt a year ago because of the pump. I have used eversince the PS stop leak( I think it is similar to Lucas) from Murray's and by checking frequently the level I do not see any need to add more and there is no whinning noise. So far so good.

I found a similar question to yours in another forum:

http://www.clublexus.com/forums/ls400-foru...r-steering.html

Good luck

Thank you all for the input.

Thanks for the input. I checked the product specs:

Product Description

Features and Benefits

For all vehicles, can be mounted in vehicle

Fully automatic with charging status indicated by LED

Reverse polarity and

short circuit protection

12 Volt, 1.5 Amp charge rate

Portable

Is this the same protection like the in-line fuse?

Thanks

No not at all. The short circuit protection you refer to is that the charger can withstand being connected to a dead short while powered up for an indefinite period of time. A useful feature but since these chargers are quite low in current it isn't as big a feat as they make it sound.

This however has nothing to do with the point of putting a fuse on the red wire right at the battery. At the risk of beating an almost dead horse to shreds I'll state it one more time. The purpose of the fuse on the red wire is to protect the possibility of the red wire somehow getting pinched which would cause a short to ground. By putting the fuse at the battery end you protect that wire from turning red hot and potentially causing a fire. Protection of wiring is always done at the source of the energy, not the load. In this case the source of the energy is the battery. This is why in your house the electrical first flows to a breaker panel before the house wiring. They protect the branch circuit wiring at the source of the energy. If the breakers where in the receptacle of your home and somehow the wiring got pinched in the wall (too tight a staple or a drywall screw) then that branch wiring could start a fire because it isn't protected at the energy source.

Its the same in your Lexus. The battery first goes through a fusible link (main whole vehicle fuse) then it is subdivided into branch circuits with individual fuses. The fuses are at the energy source before the wiring.

Thank you, you got a very good point.

WILCO.

Best

Chris

1991 with 129000 miles and drives like a charm.

http://us.lexusownersclub.com/forums/index...showtopic=57790

The exhaust tips of my 91 LS400 are the factory ones. I took them out and cleaned them but still are not to my liking. I have found these ones. What do you think-are they too much for this lady? The left is the new vs old.

From the back the new ones.

From the side

and from the distance

If you like them then try Walmart-$12.96 each plus tax.

Best

Chris

I'm not a tire expert by any means, but if it's just been two weeks, I'd take it back and have them change the wheels. Mark the tires front-left, front-right etc so they don't move location, take them off the wheels and put back on the correct ones for each side.

They messed up, they should correct it.

I'm with AZ, they should flip them back for you, just make sure they don;t go and flip the rim when your not looking to save time.

Thanks guys, wilco.

Best

Chris

Oh, you're a Snowbird, eh? You must have gotten out of here just in time, we had something like 14 consecutive 100+ degree days.

Very nice car! Am I wrong, though, but is your right front wheel on the wrong side? Those wheels are directional.

You got it right. Snowbirds we are. We have a house in the Anthem Country Club-I17 to Flagstaff. It's a Great place.

Very good eye too!!! How can you tell from the picture that my right front wheel in on the wrong side? Can you explain.

Best

Chris

What!? You don't have a place in Mesa, not a true Snowbird then.

As to your front wheel, if you compare the front and rear wheels on the right, the "spokes" or vent holes don't go the same way. I believe they're oriented such to help cool the brakes/rotors. Unfortunately the L and R stamped on the wheel is on the inner side of the wheel. You'd have to take it off to confirm but I'd bet you'll find an L stamped on it.

Look at your spare tire and see if the wheel is stamped with an R. At some point along the way when getting new tires, the technician didn't realize the wheels are directional. I haven't read any threads here discussing tire rotation, but I believe this limits you to front/rear rotation only, not the X pattern. I'm not sure how big of a deal it is operationally but, to me, it's more of an aesthetic thing. How are they on the driver's side? If there both L's then the spare is most likely an R then you could have the tires swapped the next time you're due for a rotation.

On my 90, one of the wheels was bent slightly but fortunately the spare wheel was for the same side.

I'm not saying you have to do anything but just wanted to bring it to your attention. Congratulations, though, on having such a nice ride.

I checked today the wheels. You are right :) :)

Here is the current set up:

Front:

R L

Back:

L R

Two weeks ago I bought new tires-not from Lexus and eventually no Lexus knowledge by the guy who did it. :( :( :(

Best

Chris

You LS400 is beautiful!!

I have a '91 also and it is silver with the slightly lower trim package. I noticed yours has the LS400 emblem on the right side. Mine doesn't, and I haven't notice an older one before that had it. Is it aftermarket or was that added with the higher trim package?

Thank you for your kind words.

I have paid the dealer in 1999 extra to install the gold emblems.

The 91s did come with the silver trim and no LS400 emblem on the right at all.

Best

Chris

I checked the installed charger/maintainer and it is only 1.5A. I do not think I need an inline fuse.

Thank you anyway.

Best

Chris

OK your decision. Most manufactiers recommend a fuse when connecting direct to battery and their harnesses include the protection fuse.

Thanks for the input. I checked the product specs:

Product Description

Features and Benefits

For all vehicles, can be mounted in vehicle

Fully automatic with charging status indicated by LED

Reverse polarity and short circuit protection

12 Volt, 1.5 Amp charge rate

Portable

Is this the same protection like the inline fuse?

Thanks

Oh, you're a Snowbird, eh? You must have gotten out of here just in time, we had something like 14 consecutive 100+ degree days.

Very nice car! Am I wrong, though, but is your right front wheel on the wrong side? Those wheels are directional.

You got it right. Snowbirds we are. We have a house in the Anthem Country Club-I17 to Flagstaff. It's a Great place.

Very good eye too!!! How can you tell from the picture that my right front wheel in on the wrong side? Can you explain.

Best

Chris