Just Got A 93 Ls400 Few Questions...

[HomerTHX1138]

My grandmother wanted to give me the car but I insisted I give her something SOoo, I got a really good deal ( $1500) on a 93 LS400 with 139K on it. It's been garaged for the most part, serviced by Lexus, and aside from some body work which I'm having done (her vision isn't what it used to be), is in really great shape.

She did just replace the AC compressor ($1400!?) and before that in 05 reported a fluid leak for which they charged her about $2500 to replace various internal seals, timing chain, water pump etc... I also noticed that she replaced the steering pump in 99 and read here that it's problematic on these cars.

Questions:

1 The car occasionally has a slight shudder, almost a hesistation around 40mph or so. Concerns?

2 When it upshifts to overdrive and is running at very low RPM, there's a bit of noise and vibration. Mind you it's very slight. Possible tranny mount? Other? Or nature of the beast?

3 Finally when given very little gas off the line it also hesitates just a bit. My uneducated guess thinks maybe dirty injectors. Just a bit more pedal and you don't even notice it.

Thanks in advance. Overall the car is an absolute pleasure to drive.

[monarch]

Could be way overdue for a new fuel filter, air filter, spark plugs, distributor caps, distributor rotors, spark plug wires and oxygen sensor. Could also need a throttle body cleaning and a change of transmission fluid using Toyota Type T-IV.

[CUMan]

I also have a 93 LS, and, with the exception of #2, your problems are very familiar.

The shudder you mention is very common on these models. I bought my car in 1998, and it had this same shudder at that time. A couple of years later, I had the transmission serviced (drain and fill - not a full flush), and the shudder stopped. I was not really expecting this, but was pleased when it happened. I suspect that the shudder is related to the type of transmission fluid in the car. The 93 LS was factory filled with Toyota Type II fluid. Somewhere along the way, they phased out Type II. The replacement is Toyota Type IV. I would suggest that you have a drain and fill done with Toyota Type IV and see if that doesn't fix your problem. A drain and fill would require about 2 quarts. You can purchase the fluid at a Toyota dealer at a better price than at a Lexus dealer.

I have never experienced the second item you mentioned. This, too, could be related to the transmission. A drain and fill might help with this, also.

Your third item is familiar. My car also has a slight hesitation at low speeds. It normally occurs after the car has warmed up. I have tried Seafoam and various other fuel system cleaners and have yet to see any significant difference. I suspect that this is a computer software glitch. Given the cost of replacing the computers in these cars, I have chosen to live with the problem.

Do you not have any problems with the dash display? I would expect it to be blacking out and acting up in other ways.

[branshew]

My grandmother wanted to give me the car but I insisted I give her something SOoo, I got a really good deal ( $1500) on a 93 LS400 with 139K on it. It's been garaged for the most part, serviced by Lexus, and aside from some body work which I'm having done (her vision isn't what it used to be), is in really great shape.

She did just replace the AC compressor ($1400!?) and before that in 05 reported a fluid leak for which they charged her about $2500 to replace various internal seals, timing chain, water pump etc... I also noticed that she replaced the steering pump in 99 and read here that it's problematic on these cars.

Questions:

1 The car occasionally has a slight shudder, almost a hesistation around 40mph or so. Concerns?

2 When it upshifts to overdrive and is running at very low RPM, there's a bit of noise and vibration. Mind you it's very slight. Possible tranny mount? Other? Or nature of the beast?

3 Finally when given very little gas off the line it also hesitates just a bit. My uneducated guess thinks maybe dirty injectors. Just a bit more pedal and you don't even notice it.

Thanks in advance. Overall the car is an absolute pleasure to drive.

Your car has a timing belt not a chain.

1) 1 & 3 could be related. Does item 1 happen while accelerating? Check the fuel filter and injectors

2) Probably a mount or bushing somewhere in the trany or driveshaft supports. Fluid flush may not hurt either.

3) See # 1. Also could be something in the vacuum or pcv system. You may want to check hoses & valves

Monarch has some good suggestions as well.

[HomerTHX1138]

Thanks for the replies.

CuMan, Actually that is the primary reason she finally gave the car the boot. When I received the car a couple of weeks ago the dash had basically quit working. I shipped the boards to Jim Walker on Monday and was supposed to get them yesterday but they didn't make it and should be here today.

I'll check the records for any fuel delivery related repairs. She claimed she did not save every receipt unfortunately. I can do the airfilter obviously myself and will see about having all the other items replaced. Certainly the tranny fluid drain and top is going to happen first thing.

Does #1 occur while accelerating? Not under heavy acceleration, maybe gradual. I haven't had it long enough to say for sure.

Again, #2 is not that bad. Something just hit me too that may or may not be related. When putting the car in park with the AC on the RPMs drop really low for about 2 seconds and then return to normal. I wonder if this is a low idle setting? Does the tranny use engine vacuum to operate?

OT: Finally I typed that last paragraph's last sentence with difficulty: I just sold my 83 Mercedes 300D which I had driven for years and loved, after I got the Lexus. The one thing that was always flakey on that car was the vacuum and in fact I had the vacuum pump and some valves replaced as a condition of the sale to fix the transmission shifting (clunking on the 4-3 downshift, hard shifts) But that car was bulletproof in most ways.

[HomerTHX1138]

Updates:

Throttle body cleaning (outlined in another thread) fixed MOST of the off-line hesitation. It's better, but not perfect. Distributor caps and rotors were replaced a couple of months ago with the timing belt and other internal work before I took possession.

Today I had the fuel filter replaced, the tranny filter replaced, and fluid changed with Toyota Type IV. Issue #1 and #2 are still present. I asked the repair shop (a national transmission chain) to inspect the motor mounts and transmission mounts. They said the mounts were not cracked. They also test drove the car and didn't notice any problems.

SO,

The spark plugs and wires may still need changing.

Are dirty fuel injectors a possible factor? Which dealer service do they change them, if any?

Thanks in advance

[93ls400walt]

Try a can of BG44K fuel system cleaner. Available at most dealers. Web www.bgprod.com for info on it.

Then do the plug/wire change. I think that bosch fouls out early. I put NGK iridium. I'm very happy with them.