Gs400 idling high when shift gear it sound line engine moving.

usually it is a vacuum leak which is letting more air into the engine. With engine running, use a spray water bottle and mist around all vacuum lines, the power brake booster and engine seams. Then try any vacuum line to the transmission. Could also be a burst vacuum shift diaphram if so equipped.

The car pulls suddenly hard in forward or reverse direction at the moment you change gears.

The reason for traction light to come up is due to high idle. Set the idling screw to proper amount and the check light may go off.

Sounds like a fuel pressure problem check fuel regulator by taking vacuum line off and checking for fuel laying inside line.If fuel is in line replace regulator.If no fuel in line then check pressure it should be 9-13 psi with key on engine off.If not within specs replace pump.

Dont throw it off a cliff just yet :-) Just check the vacuum line from the inlet manifold back to the transmission, ensure that fittings are air tight and that there are no holes in the line.
Explanation for possible fix:- When the car is at idle the inlet manifold plenum has a reasonably high vacuum generated within it. The vacuum line to the transmission conveys this drop in pressure to the shift solenoid. When you accelerate slowly you hardly open the throttle and the vacuum remains high in the system. The solenoid allows early shifts through to the higher gears. If you accelerat hard the throttle is open wide and hardly any vacuum is maintained. The shift solenoid, in the absence of vacuum in the line, now holds each gear for much longer allowing the engine to use its full power band.
If the inlet plenum suffers from an air leak or the vacuum line to the transmission becomes loose or a leak develops in it the solenoid reads this as if the car is accelerating hard and wants to hold each gear for as long as possible. This situation sounds like your problem so check that everything is free of any possible leak. If you find a leak and cure it not only will the shift pattern be fixed but your engine idle will be much better too.

Check this first. On the transmission there should be a small vacuum line that goes all the way to the inlet plenum, check that both ends of this line are are connected securely and that the line has no holes in it. This vacuum line governs the rate at which the transmission moves from one gear to the next. When the engine is running slowly, just above idle, the throttle plate is all but closed and the car will shift through the gears pretty quickly as there is no load and plenty of vacuum. If on the other hand when the engine is racing under load, with the throttle plate fully open, there is little vacuum and the transmission holds in gear for very much longer before up shifting. If this vacuum line is disconnected or leaking the transmission will interpret this as the engine under load and will be very tardy in up shifting.

sounds like you have a vacuum leak somewhere

sounds like two problems 1 engine can idle high with vaccum leaks or bad idle air control or maf sensor 2 if trans wont shift in to gear fluid first next would be to tcm or wire connection on trans good luck

sounds like the clutch has had it mate.
get it repaired or just get a whole new clutch from ebay

it sounds like you have a vaccum leak more than likely. check near the intake manifold near the fire wall there are several vaccum lines there. also remove the the breather hose and check that your throttle plate is not sticking(this of course only applies if you have fuel injection. if you have a tbi or it's carburated check the throttle linkage to see if it's perhaps sticking