Cylinder Head Swaps Mazda 626 from 1993 1,8i to 1996 2,0i

Not knowing what the actual problem is I can only suggest the firing orders.
Is yours the four cylinder engine or the six cylinder?
The Four cylinder engine will probably use the sequence 1, 3, 4, 2, as this is usually the most common one in use. Cylinder One is the cylinder nearest the belts and pulleys and you count away from you towards the transmission and gearbox.
The six cylinder uses the firing order 1, 2, 3, 4, 5, 6. Cylinder One is also at the belt and pulley end of the engine but the numbering is different on a 'V' engine. The numbers go 'left, right, left, right, left, right' odd one side evens the other.
Stand next to the engine with the gearbox furthest away from you and the end with the belts and pulley wheels nearest to you. Number One is the cylinder nearest to you on the Left. Number Two is the one nearest to you on the Right. The Left side is numbers 1, 3, and 5 and the right side is 2, 4, and 6,

Thread Head bolt torque and sequence
Read the threads, but it states:
According to my manual the removal and the replacement sequence are different. Removal (looking from the cam sprockets )
headbolt 1-3-9-5-7 are on the left and 2-4-10-9-8 are on the right. Remove in that progression.
Instillation 9-5-1-3-7 are on the left and 10-6-2-4-8 are on the right tighten in that order.
Tighten to 25Nm or 18 ft/lb. and retighten the cyl hd blt 70 deg plus 70 deg plus 50 deg using the angular torque guage KM-470-B.
Hope this helps. Might help to make a sketch and label the 5 headbolts on each side.

The left head is located on the left side of the motor, when you're sitting in the vehicle. When you're looking from the engine compartment directly at the motor, the left head/side would be just the opposite. facing the motor with the belts looking at you, the left head would be to your right side. The number one piston/cylinder is the head wher the front of the head is closest to you when standing and looking at the belts.

Cylinder head cracks are rarely visible, can usually only be found with testing equipment found in machine shops. If the head comes with at least a minimal warranty, you can have the head tested as soon as you recieve it for your own peace of mind. Head testing is generallly cheaper than having to replace the head later.

Hope this helps!

Timing marks on the 3L motor are: (looking from the front of the engine) right side camshaft sprocket (1 dot on sprocket and the cylinder head); left side camshaft sprocket (1 dot on sprocket and clyinder head); crankshaft sprocket (arrow on the block and an inverted arrow on the face of the sprocket) and of course the timing belt cover

looking under hood to the back left cylinder.that number 1 follow it to coil number 1.

Its tighten to this amount then by angle

25. Cylinder Head W/intake Manifold
· Clean up cylinder head lower surface and cylinder
body upper surface.
· Install cylinder head as softly.
· Apply engine oil to screw and seat of cylinder
head bolts.
· Tighten cylinder head bolts in following sequence
1st Step

36 Lbs /ft
2nd Step
60° - 1/3 a of a turn
3rd Step
60° -- same

And thats in a spiral out from the center .

1cylinder is first from passenger side of car!firing order is 1342!

a weep from the cylinder head gasket. try retorqueing the cylinderhead

hi.im a mechanic from the philippines.the torque of all your cylinder head for your nissan sentra 1997 is 60 nm.apply 30 nm of torque first on all the cylinderhead bolts then torque it agian directly to 60 nm. i also drive and repair nissan cars.