Just did a tune up on my ls400 but still will not crank i know it a igition problem what else could it be besides spark plug and wires

We all know that feeling, especially the broke part. Stop throwing parts at it. You need a good diagnosis. For "cranks, no start" check fuel pressure and spark. For no spark, use a wiring diagram and understand what is involved. The crank and cam sensors are usually part of the mix. The computer (pcm) uses these sensors to determine spark timing, and often injector timing. Also besides coil, plugs, and wires, and the sensors mentioned, don't forget how the ignition system controls the coils- the ignition control module, or ICM. This little part is often the cause of no spark. But, everything can and should be tested first.

cranks but will not start still , after 40 days?
does it have spark to all 4 cylinders.
that be first.
and if rotor still spins cranking
if you fooled with spark plug wires, or tuned it up./
old post answered.

Check for spark to the spark plugs during the no start period. If you do not have spark the crank sensor in the distributor is a common failure in these.

You don't say what year you have so I'm not sure if you have the older version with dual distributors, up until 1997 or 1998 above with coil on plug. If you have a 1998+ , there is no chance that all 8 coils failed so I would look elsewhere. In my professional opinion, I would focus on the crank sensor. If the ECM is not getting the crank signal, it doesn't know where the #1 cylinder is so it will not fire.

CHECK FOR SPARK AND FUEL.IF ALL IS GOOD A BAD COLD START VALVE WILL CAUSE COLD ENGINE START UP PROBLEMS COLD START VALVE DOES SAME JOB AS ENGINE COOLANT TEMPERATURE SENSOR IT ENRICHEN FUEL SYSTEM FOR COLD START UPS. DO LITTLE TUNE UP MAKE SURE SPARK PLUGS AND WIRES GOOD, REPLACE DISTRIBUTOR CAP AND ROTOR,CHECK IGNITION TIMING, REPLACE AIR FILTER AND FUEL FILTER. IF CAR GETTING FUEL AND SPARK.CAR TIMING BELT COULD HAVE JUMP TIMING IF TIMING BELT NEVER BEEN SERVICED OR REPLACED.

No spark no injector pulse your saying you check pulse. With the key in the igition is there a key sign flashing and does the key have a battery for alarm. For the fuel pump to operate it need a crank signal so you got the crank correct but no spark so the crank works. Can you check the ignition for pulse you know how it is shape its curved on one side staight on the other side well the curve side and at that end is the ground after that on is the control from ECM. If you can check pulse there then we can go to the ECM . What I am trying to get at is this your alarm is the only thing beside the ECM that can cause this.

You will need to make sure that the health of the car is good. Make sure that the fuel , fuel filter and the delivery is good.
Secondly check the spark intensity, check the plugs, the wires and trigger for the coils. make sure all electrical points are tight and clean so as the starter cranks without any lagging.
Finally check the plug gaps, the timing and fuel tuning.( hope the valve settings are good)

If you changed the camshaft and/or crankshaft sensor, it will need a CASE learn to be able to run.

It should be tune up as replace the cap, rotor, spark plugs, wires, PCV vale and Mass flow meter. so many problem when this happen.

good luck!

I'll send you 2 pictures, 1 will be your engine. I picture in each post.