Hey guys my 2000 galant 4g93 wont idle properly when you put it in drive the idle speed drops even further and the car shudders alot have to balance the trottle by stepping on the brake and reving it when i come to a stop light but once the car is moving it runs good

Shuddering and shaking indicates that something is out of balance. In normal circumstances this would be attributed to out of balance wheels, worn steering joints or a worn coupling on a propshaft.

Grinding when put into gear may indicate that the torque converter in the autobox is worn and/or out of balance.

It's not a good idea to drive the car if it shudders and shakes as you're likely to cause further damage to something. The most sensible option would be to ask a workshop for a diagnosis first.

tires out of balance or a bad wheel bearing

You need to find out which system is causing it first. Lift it and run it like that, get some help and find the source of the shudder

You say that it attempts but fails. If it turns over, at a normal speed and tries to start and doesn't, check that the fuel is good and new fuel. Not fuel that has been in the tank for a long time. Check the fuel filter to see if it is clogged, Check the fuel injectors to see if they are all spraying fuel and there is enough pressure in the fuel lines. Check fuel pump for proper fuel pressure. High mileage engines check for compression in each cylinder. Possible bad ignition wires or ignition timing is off. Has the engine been steam cleaned recently. Is there water in the fuel? This gives you some things to check. Good luck.

check air idle valve under throttle body

adjust idle

idle control valve. bad plug wires and bad plugs will all cause that as well as a air leak in the vacumn hose on galant

idle air control valve or your fact idle valve is not working properly, all two of these are housed in the throttle body.You can try cleaning the throttle body firet if it dont work you knpw what to do. Good luck.

the correct transmission fluid is ATF+4, any other trans fluid will spoil the transmission.
i use platinum spark plugs in my engine, works great.

Can you tell if your car is a GDI or MPI? What do you mean by buking? Can you describe the problem a little bit more...like when it does it cold or hot full throttle or slow openings?