1998 BMW Z3 1.9 Cylinder misfire codes. Rough on cold wet starts

code p 0305 is the no 5 cylinder misfire and included in the list of causes are plugs and wires but unfortunately also in the list of causes are== injector, injector connections and wiring and this is the most common area of the misfire and not the plugs or ignition circuit
pull and check no 5 injector and place it in another cylinder and see if the fault moves to the new cylinder
if it doesn't move it is in the wiring and control
if it does move , replace the injector

Is the engine running rough?

Is the same cylinder causing the problem? If so take a close look at the spark plug for fuel fouling. The cylinder may be over fueled causing plug fouling. You may also have a bad coil or defective spark plug. Try swapping coil and plug with one from adjacent cylinder to see if misfire changes to that cylinder

Could be several things, such as leaky fuel injector flooding cylinder after shutdown, or oil fouling plug due to bad valve guide seal of broken piston ring. Install brand new plug, run about 20 miles, let engine get cold overnight, remove plug to red is it wet with gas or oil sooty.

The flashing and rough running is to to a misfire or misfires cause by arcing due to moisture on ignition components. Eventually these misfires can lead to other problems such as damage catalytic converter. Start by identifying which cylinder(s) is/are misfiring. The arching can be reproduced with a spray bottle filled with soapy water. Spray the ignition components (wires, coils, distributor cap...)and look for the vehicle to idle rough. Replace any faulty component.

Here you go - this'll help you translate your engine codes. Looks like your getting a "Multiple Cylinder Misfire With Fuel Cut-off" and "Misfire Cylinder 5 With Fuel Cut-off". Hopefully you just need a good tune up, but this should point you in the right direction. Good Luck.

http://www.obd-codes.com/trouble_codes/bmw/

P0301 Cylinder No. 1 Misfire Detected
P0302 Cylinder No. 2 Misfire Detected
P0303 Cylinder No. 3 Misfire Detected
P0304 Cylinder No. 4 Misfire Detected
P0305 Cylinder No. 5 Misfire Detected
P0306 Cylinder No. 6 Misfire Detected
P1346 Variable Valve Timing (VVT) Circuit Range/Performance Fault
P1349 Variable Valve Timing (VVT) System Malfunction
P0330 Knock Sensor
P0446 EVAP Vent Control Fault
P0430 Catalyst System

Stop driving immediately.....

You defiantly skipped on your timing........

Hi, the 4.3 liters have an injection system on them that can leak and will show up as a misfire. it is common but elusive to find. you might consider taking the van to a repair shop to have the problem diagnosed and go on from there.

all the codes you have are all related to the fuel trim, this problem needs to be looked at with a european capable scanner for futher tests sorry.

the problem could be in air mass flow sensor, but it's expensive