My truck is spitting and spuddering when it gets up to about 45 or 50 the more i give it gas the more it acts up. it cranks fine and doesnt smoke

Clean the idle speed control valve in the upper intake near the throttle valve with CRC brand throttle cleaner.

smoke smell like burning oil or hot antifreeze..

Code 1683 is for a problem with the EGR solenoid which controls the EGR valve, and code 597 is for the IAC valve not being able to keep idle speed at the correct setting.
A leaking EGR valve could cause the symptoms you describe.
I assume you looked at the cap and rotor and they are ok.

Great!

compression test
check for internal crack in turbo
replace plugs
check for blown head gasket

manufacturer decided they wanted a unique system of fuel injection, at least different then that of most systems. The control valve may act up and not allow fuel to inject at intervals. Instead, it may take be clogged with debri, gunk, and other trash which needs to be serviced in a shop to be repaired. One very common activity with your fuel injector is it may cause the valve to stay closed and burn gas in a manner that is inconsistent with normal gas usage, the vehicle will start to blow out black and dark smoke out the rear end, trick your cars oxygen sensor, and allow the system to burn a larger amount of fuel for the same mileage. This problem needs to be solved in a shop where the equipment is available to make adjustments and flush out your system.

pump and filter are in the fuel tank. the box you speak of could be the bottom of the trunk or a vacum canister.

A good pump and a bad one look identical; problem with the bad one is that after running for a while, it gets hat, begins to bind and then stops. Once cooled down, it will repeat the process. Even when pressure testing, it may "seem" fine but not be., 'till it gets bad enough to show up during testing. Your crank position sensor can act the same way, so can an ignition coil. (internal expansion during heating shows internal shorting.) When in "no start" check for spark. This should separate fuel problem from ignition related stuff. Then, go from there. Do real testing...guessing and replacing parts can cost you a fortune.

Hello

I am also facing the same problem

http://consumerguideauto.howstuffworks.com/1990-to-1994-chevrolet-lumina.htm

This will help you

Thanks

looks like you need a fuel pump. your current pump is dying.
and wont send enough pressure.