Engine will not run properly and appears to be missing on all cylinders. The fuel pressure and eletronics are fine.

If your 96 E250 300ci was running perfectly and then started missing and the code is indicating a miss fire in cylinders 1 and 2, there could be a few potential causes. Here are a few steps you can try to troubleshoot and resolve the issue:

1. Check the ignition system: Make sure that the ignition system is functioning properly. Check the distributor cap, rotor, spark plug wires, and ignition coil for any signs of wear or damage.
2. Check the fuel system: Make sure that the fuel system is functioning properly. Check the fuel filter, fuel pressure, and fuel injectors for any signs of wear or damage.
3. Check the compression: A compression test can help to determine if the engine is getting enough compression to run properly. Low compression in cylinders 1 and 2 can cause the engine to miss fire.
4. Check the vacuum lines: Make sure that the vacuum lines are properly connected and not leaking. Any vacuum leaks can cause the engine to run poorly and miss fire.
5. Check the PCV valve: The PCV (positive crankcase ventilation) valve can become clogged or malfunctioning and cause the engine to run poorly and miss fire.
6. Check the EGR valve: The EGR (exhaust gas recirculation) valve can become clogged or malfunctioning and cause the engine to run poorly and miss fire.
7. Check the Engine Control Module: The Engine Control Module (ECM) controls the ignition and fuel systems and if it's malfunctioning it can cause the engine to miss fire.

It's important to note that some of these steps may require special tools and knowledge of the vehicle's engine system, so it's best to take it to a professional mechanic to avoid causing more damage.

Sounds like. MAP sensor or cam sensor. You didn't say if Chechen engine light is on. No light on check throttle. body and TPS . it may be loose.

change the fuel filter if you have not done that does it have a check engine light on?

Seems that the fuel pressure regulator is bad, place a vise on the fuel return hose and if the car runs well replace the pressure regulator.

Have a fuel pressure test done to determine if proper pressure is there. At very least change fuel filter.

if you have only one cylinder getting that excessive fuel it indicates that the computer thinks that that cylinder is not sparking and thinks no fuel is the proble. this is due to a timing issue. even though you replace the injector which was most likely not the problem to begin with. in order to get spark the coil has to energize you more than likely have a bad coil pack.replace the coil and your miss will no longer exist.

put gas in it

Have fuel pressure checked at fuel rail, scan ecm for codes or replace fuel filter.

I think that the problem comes from the alternator.

Your O2 sensors may be freaking out. The O2 sensors tell the ECM how much fuel to send through the injectors. When the O2 sensors quit working right, the ECM has no idea what to do with the fuel. Do a fuel pressure test as well. If the pressure regulator is working correctly, it'll go through alot of fuel as well. You should be at 40 psi. When running you should be at 37 psi.