Lexus Daddy

I have a 93' LS and my question:

My LS hesitates just a bit when I press the
accelerator pedal. It does not do this when I have the
Driving Pattern switch set on "PWR" (off of normal).

Is this normal? Anybody else experience this?

Thanks.

GA400

I see this too occasionally. I was going to swap out the fuel filter to see if it fixes it (once I figure out where the darn thing is). I have already replaced the air filter and put some fuel injector cleaner in my gas, didn't fix the occasional hesitation but it did help my performance overal.

Rich

Lvangundy

Same situation here.

I seriously think it has something to do with the transmission or torque convertor. The hesitation just reeks of tranny to me..maybe not. I get the most hesitation at about 800-1100 rpms.

so.. I plan on changing fuel filter, spark plugs + wires (which I think will help the most) and reflushing the tranny again with Toytota Type IV.

I think the transmission flush will help with the car not losing it's rev speed at you let off the gas when coasting. If the fluid if really thin there isn't any pressure to keep the RPM level around where it is when you let off the gas, so it drops quickly.

GA400

Lvangundy,

If you don't mind, I would appreciate you letting me know what kind of impact this has on this problem and your performance overall. Feel free to e-mail me via my profile here. I have thought about doing all of those things to my Lexus too. The tranny fluid flush job, is that a diy job or would I need to have a shop do it, in your opinion?

Rhlight

FusionMan79

You may want to change the differential fluid as well. I think I remember reading something about a fluid pass through from the transmission to the differential in a TSB or something. If I'm wrong about this and someone knows for sure please post, it was a very cursory reading, something about allowing differential fluid to cycle better or something. Might be a good idea to change anyways though. Plus, try driving with overdrive off. I have some hesitation problem as well and shifting seems much better with overdrive off. I'm starting to think maybe the overdrive band has gone bad.

hyperopt

Transmission fluid is self-contained and is completely separated from differential fluid. Same for differential fluid, and differential fluid is the least likely cause of the hesitation described. Hesitation is usually due to problems in engine, trans, and/or torque convertor with the engine is the most likely source.

VVT-i

I agree with hyperopt. If the problem goes away in the Power mode, that mean the engine is o.k cuz if you have an engine problem then it's doesn't matter which mode you're on. I'll take it to the shop and get the trans. flush with type t-iv fluid first.
I know this is stupid question, but all of your tail lights working properly. There a harness in the left side of the trunk that run under the trunk's hinge. If one of the wire in that harness broke, it will give you all kind of hesitation problems too. Just my 2 cents. I hope this help.

Lvangundy

rhlight - yes I don't have alot of time to respond, but the trans flush did help with the overall solid feel of the transmission.

Make sure they flush and replace with Type IV fluid.

For everything else, I think the transmissions on the first gen LS are built to last, not really get any performance out of. It's a slow tranny, and when you start driving the hell out of it, it gets boggy and lagged. If you want to invest the money try replacing the torque convertor (maybe aftermarket performance if you like) I think that will help alot as far as how the car feels off the line. I'm SURE mine is wore all to hell. ;-)

GA400

lvangundy,

thanks for the reply. I am not sure if mine even has the type IV tranny fluid in it at all, since it had so many miles when I bought it. I will definitely be replacing the fluid next time I get it serviced. I will keep the stock torque converter. I have no plans to race or go fast, except during highway cruising.



Thanks for the advice,

rhlight

Lexus Daddy

VVT-i,

Could you expand on that statement?
In fact I do have a tail light out dummy light on,
I cant seem to get it to go off. ALL of my lights
are working properly!

Are you saying a broken tail light wire can cause
this?

Have you experienced this?

Thanks to everyones replies!

VVT-i

Lexus Daddy... the ground wire that run inside the trunk lid also share the same ground with your Throttle Position Sensor and some other sensor as well. It will not show on the wiring diagram, but some times you step on the brake, your Reverse light on the combination is comes on or some of the tail light is dimmer than other. Some funky stuff..
Open the trunk, under the left side of the hinge, you'll see the harness and a small plastic cap ( U shape). Open that U cap you may find some of the wire(or wires) is broken from the trunk being opened and closed for so many hundred times and it will stress the wire after the period of time.
I hope this may help. Please let us know what's going on.
Good luck

GA400

VVT-i,

Thanks for that tip. The last time I cleaned my trunk, I remember noticing that wiring bundle was worn and I thought, "I need to tape that up to make it look better". By weird coincidence, I have had to change three brake light bulbs in the past month. I still get the hesitation on rare occasion (maybe three times a week) although changing the air filter and running the fuel injector cleaner through seems to have helped with performance overall. Looks like there is a connection here and I would not have ever known if you hadn't told us!

Thanks a million,

rhlight

capper

rhlight...

the aforementioned problem of the Reverse light coming on (as well as the bulb out light on in the console) is a ground loop break in that part of the wiring harness (drivers side trunk)..mine did this too, and I thought the derned transmission was trying to kick into reverse everytime I hit the brakes (it made an odd down throttle)...actually what it is doing when that ground loop is gone is kicking it out of overdrive...hope this helps...by the way, there is not a lot of room in that wiring, and it's hard to get back together (at least it was for me) without breaking the strain relief on the wiring...I pieced it back myself, but had Lexus re-spec the strain relief when they did the other major things I had done to "renew" my car last week...Capper

VVT-i

Capper has good explanation on this little problem..thanks
rhlight you may need to check the tail light socket itself.. for the one that had problem repeatedly.
This is just a wild guess for Lexus daddy's problem. It's not a sure fix, but it cost nothing and it's worth a try. There's may be something more complicated than that, but his problem only in Power mode, so I think it's not mechanical problem.

GA400

Everyone,

Thanks for the advice, I will check it out. BTW, the three bulbs I replaced were in separate locations - trunk lid, one on each side, and high mounted, the one in the middle. So it doesn't to be isolated to a specific socket. (I didn't explain that earlier, VVT-i :-)

rhlight