My 1994 LS400 has no acceleration in D1 has some in D2 and will barely accelerate in L. Same problem as posted by simmonsa. tried coils, fuel pumps, shop replaced cats, maf, and ecm. still won't accelerate. idles beautiful.............

1. check transmission fluid level or if you can change the fluid & filter.
2. check throttle position sensor (tps).
3. if fluid level & tps are ok & still not upshifting automatically, temporarily (so you can take it to a transmission specialist) , try to manually shift. starting from dead stop, shift to D1. at about 25mph shift to D2. (be gentle on the accelerator & don't over rev on each gear. release accelerator pedal & don't step on the brakes while shifting from D1 & D2).

I have the same problem - did you find a solution yetI bought a used on ls400 ECU from a junk yard but it eeds to be "RESET" how do I do that?

Thanks for choosing FixYa and welcome. Something is draining the battery, eventually killing it. Have you had starting problems in the past? Is the car cranking? Have you checked anything, such as alternator, terminals?

Check your MAF.

Wish I had an answer - sounds very much like a problem I am having with my '92 LS400. I have a parts car, and have changed out the ECM, fuel pump, injectors, fuel pilter, fuel pressure regulator, ran the can with exhaust unbolted (check for clogged CATs, checked out my timing belt for slippage amoung other things, and nothing works. I have no check engine light on. Do you?

I would put a new fuel filter on and try that. If that didn't work, sparkplugs and wires, and a distributor cap and rotor. Also make sure your air filter is clean.

Check/change air filter.
Check/change spark plugs & plug wires. The wires can be check with an OHM meter, and the specs for the resistance in the manual. So can the ignition coils.
Change fuel filter...easy.
Last, if you have scanner...check MAF(mass air flow sensor) for operating specs...5g/sec at idle to 300gal/sec+ @ 3,000 RPM.

Check the MAF sensor, If this malfunction, the computer cannot determine how much air is going into the engine so it can't determine how much fuel to put in there. Also a bad coil, or any part of the ignition system can cause this.

could be your fuelm pump is going out on you.

I HAD THE SAME PROBLEM WITH MY CAR. 93 LS 400. THAT WOULD BE YOUR FUEL FILTER OR THE FUEL PUMP GOING BAD. TRY CHANGING THE FILTER FIRST. THE DEALER TRIED TO CHARGE ME $980 TO CHANGE FUEL PUMP.