Engine missing wont fire properly, i think its the spark plugs how do i change them ?

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.

It's already not start before you changed or after changed ?
If before. the timing belt or might be broken , burn fuel pump's fuse, injector's fuse or main engine relay.
If after. It's possible miss some wire that still not connect.

Mai

remove the plug from the #1 cylinder, and install it into the #2 cylinder , and put plug from # 2 clyinder in to #1 plug hole, connect plug wires, and start up vehichle, and if computer shows misfire on # 2 cylinder , then you have a bad plug, possibly porcelin insulator could have a hair line crack in it, hope that this information has helped you.

Check proper firing order first then make sure u didnt sqish a spark plug? Did it miss fire before work was done?

If your car is miss firing and your husband changed the coil packs,the wires leading from coil packs to sparkplugs must have got crossed.This will change car timing which will result in the car miss firing.He needs to go over wiring and correct problem for car to run right.You can go online to autozone.com and type in Info about car to get the correct wiring layout.Your problem isnt the new plugs n wires.Its the wiring layout.

Hi, I think you have not connected the proper electrical wirings it needs to feed the coil, starter motor and distributor, Try retrace your step again you must have missed some wire connection.
You're running with the twin turbo ones I assume. So by way of description you have done all the right thing except power the motor propperly. Cheers

P0300 Multiple/Random Misfire detected.
P0301 Misfire detected - Cyls. 1-4.
P0302 Misfire detected - Cyls. 1-4.

change plugs and wires distributor cap and rotor.+coil.if all is good .do a compression test.

usually its the plastic housing, also could be injectors not firing properly.

here is a little thread that should help...
http://www.automotiveforums.com/vbulletin/t644772.html

remove all plugs adjust the gap to 0.2 cm to 0.27 cm remember not to break them while adjusting the gap. or else check the spark distributor and contact me.