Afternoon I have a opel kadett 1.6i it's a 1999 model can you please tell me the correct firing order for it please

Question edited for clarity. The 'Addition Information' area is for us to ask you questions before committing to an answer. I incorporated that into your question and corrected spelling and tossed in a load of CAPS.
Question moved to model category.

The important thing setting up the cam timing is not only that piston 1 is at TDC, it must also be on the firing stroke, in other words both intake and exhaust valves closed.

Diagrams and videos in the link

https://www.google.com/search?q=opel+kadett+1600+cam+timing+marks+diagram

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What year is this vehicle? Some manufacturers mark the distributor cap where number one is. If it isn't marked you can use a ratchet and socket to manually turn the crank clockwise until the timing marks line up correctly. When you then check the rotor inside the distributor cap it should be pointing at the terminal for cylinder 1, then working clockwise fit the rest of the plug leads in the correct firing order. I think the firing order is 1, 3, 4, 2.
Number 1 is the cylinder nearest the Belts and pulleys on the end of the engine.

well that firing order is wrong!
an Opel Kadett 200ie, 1996
no country told and 15 engines used world wide this car.
last one in UK is 1995
so I guess it is not UK?
sold under 11 names world wide.
IN UK it is really a Vauxhall Astra Mk II. badged as Opel. now that is confusing.
not diesel, but petrol AND ALL ARE INLINE 4 BANGER'S.
every car made ,every manual for for them in print tells you 2 answers ( distributors)
1: lost all distrib setting
2: or not lost SETTINGS, Crank not turned.

so read that book it tells you to do this.

SPIN ENGINE TO SEE DISTRIB ROTOR ROTATION CCW OR CW/? (HOLD THAT THOUGHT)
by hand
set crank pulley TO TDC ,-0 DEGREE'S AND BOTH VALVES CLOSED #1 CYLINDER. (CALLED FIRING)#1
CAP OFF. MARK ROTOR #1 TO DISTRIB BODY
THEN CAP ON AND MARK #1 ON CAP.
PUT #1 WIRE TO #1 CAP
AND 1,3,4,2, IN CW OR CCW DIRECTION SEEn ABOVE. at FIRST STEP.

DONE car runs.
if distributor was pulled there are 15 engine answers.

next time on all cars made on earth with HV spark wires
do them 1 at a time. and win.
distribs or any car with HV spark wires seen (sets)

If the shaft jams, the valve timing is incorrect.

Firing order is 1,3,4,2

Buy a copy of the "Vauxhall TIS" dvd from eBay. These have wiring diagrams for all Opel cars

Conrod torque settings for opel cadett 1.6 gse

please specify the actual year of this vehicle as the opel kadett was stopped in about 93 and the astra introduced ,in europe anyway so please state the exact year and build country as this can vary as well ,been caught out on this before with ford escort ,and a californian model that bears no resembelence to a europeon model of the same year