2002 chevy 6.6 duramax wont start even in warm weather or after motor is warm..... only starts with starting fluid. codes are p0335/p0193/poo87/p0090

Is it automatic or manual. If it's automatic try putting it in neutral and then starting it

You need a dealer, there is a real problem going on here, way over the head of any home do it yourselfer. The main reason is the special tools required to interface with the control modules that are throwing these codes

6 6 Duramax Crank no start GM Chevy GMC Tech Tips Angry mechanic
Duramax LLY FICM Injector Trouble Misfire Part 1

suggest you look at a bunch of these youtube videos .

Leaking intake manifold (vacuum )

You have valves inside the transmission and electronic controls inside the transmission. When cold, valves do not work because the fluid is too thick. Once warm the fluid thins out and allows tranny to shift OK. You can burn your tranny up by not letting it warm up.

Check spark plugs, leads, distributor cap & rotor arm, fuel pump, fuel filter, coil pack(s), relays, replace any items that are suspect IE Fuel filter which has probably not been changed since new even though they should be changed on all vehicles every 18 months, all of this can be done at home & will save you a lot of bucks in mechanic/garage fees,

I am told the glow plugs heat up in "firing" order, also the Duramax uses a intake air heater to warm the air on cold starts.

Sounds like the PRNDL switch on the side of the transmission. Be sure and clear the code before trying to start after replacing it.

i would change the fuel filter i had the same issue on a 01 chevy duramax. as well as put some 911 emergency in the tank. you get that any auto parts store.

if it dont have good compression it will not start check the comp and make sure there no water in oil if fuel pressure is low it will not pop the injector open try some starting fluid