Timing Belt has come off. What do we need to do?

It is recommended that a timing belt should be change every 100,000km. Honda's and Acura's especially. Whenever the water pump is changed, it is also wise to change the timing belt too as it is all in one spot, and VS. In some cars, [Acura's], when the timing belt breaks, it also can tear your valves in your engine apart, so I hope that this answers your question

Arrows point to timing marks in correct position.

Below is the master help link provided to go through belt routing diagram:---Timing belt, drive belt, serpentine belt, accessory belt, fan belt, engine belt routing diagrams for all types of car models?
Click the link below: ----

http://carbeltrouting.blogspot.in/2012/02/timing-beltdrive-beltserpentine.html
----------This will help. Thanks.

I need a diagram on how to line up a timing belt for a 1996 chevy cavalier 2.4l

1. Remove the timing belt.
   

   Crankshaft and camshaft timing marks-2.4L engine
   

   Timing belt tensioner-2.4L engine
   

   Camshaft sprocket alignment-2.4L engine
   

   Timing belt installation-2.4L engine
   

   Timing belt tension adjustment-2.4L engine
   

   Timing belt tension verification-2.4L engine
   
   

Timing Belt Removal & Installation SOHC To Remove:

1. Disconnect battery negative cable.
2. Remove fresh air duct.
3. Drain engine coolant into an appropriate container and retighten radiator drain plug.
4. Remove upper radiator hose.
5. Remove fan clutch assembly bolts.
6. Remove 5 cooling fan shroud bolts.
7. Remove fan shroud and fan as an assembly.
8. Loosen alternator mounting bolts and remove drive belt from pulley.
9. Remove fan pulley.
10. Remove 4 cooling fan assembly bolts.
11. Remove cooling fan assembly.
12. Remove 4 bolts and upper timing belt cover.
13. Remove 2 lower bolts and lower timing belt cover.
14. Loosen adjusting bolt and remove A/C belt.
15. Remove alternator belt.
16. Loosen power steering pump lock bolt and mounting bolt.
17. Remove drive belt from crankshaft damper. Camshaft timing marks
    
    
18. Turn crankshaft until timing mark on front housing and the arrow "2" on the camshaft pulley align.
19. Remove 5 bolts and remove damper.
20. Remove timing belt guide from timing belt pulley.
21. Loosen tensioner lock bolt.
22. Pry tensioner away from timing belt and tighten lock bolt to relieve tension on the timing belt. NOTE: Mark the direction of timing belt rotation on the belt if it is being reused.
    
23. Remove timing belt.

To Install:
Timing belt pulley timing marks

NOTE: Timing belt pulley timing mark and timing mark must be aligned.
Camshaft timing marks

NOTE: The arrow at "2" on camshaft pulley must be aligned with timing mark on front housing.
Timing belt installation

1. Install timing belt with minimal slack from timing belt pulley to water pump and from water pump to camshaft pulley.
2. Loosen tensioner lock bolt until tension is applied to timing belt. CAUTION
   Do not turn crankshaft counterclockwise.
   
3. Turn crankshaft pulley 2 full turns clockwise and ensure timing marks are properly aligned.
4. Tighten tensioner lock bolt to 33 ft lb (45 Nm).
5. Apply a force of 21 lb to timing belt midway between idler pulley and camshaft pulley.
   • Deflection should measure 0.43-0.51 inch (11-13 mm)
   NOTE: if timing belt deflection is incorrect remove timing belt and install NEW tensioner spring.
   
6. Install timing belt guide.
7. Install crankshaft damper pulley.
8. Install 5 crankshaft damper pulley bolts. Tighten bolts to 132 in lb (15 Nm).
9. Install power steering pump drive belt.
10. Adjust power steering pump drive belt tension and tighten lock bolt and mounting bolt.
11. Install alternator drive belt.
12. Install A/C drive belt.
13. Install lower timing belt cover and bolts. Tighten bolts to 84 in lb (10 Nm).
14. Install upper timing belt cover and bolts. Tighten bolts to 84 in lb (10 Nm).
15. Install cooling fan assembly and 4 bolts. Tighten bolts to 27 ft lb (37 Nm).
16. Install fan pulley.
17. Install fan clutch and shroud as an assembly. Tighten bolts to 74 in lb (8 Nm).
18. Tighten 4 cooling fan nuts to 16 ft lb (22 Nm).
19. Adjust alternator belt tension and tighten alternator mounting bolts.
20. Install upper radiator hose.
21. Install fresh air duct.
22. Connect battery negative cable.
23. Refill/bleed cooling system.

DOHC To Remove:

1. Disconnect battery negative cable.
2. Remove fresh air duct.
3. Remove 5 cooling fan shroud bolts and 4 thermo-modulated fan nuts.
4. Remove 4 thermo-modulated fan shroud fasteners.
5. Remove generator drive belt.
6. Remove fan pulley (located above crankshaft pulley).
7. Remove 4 bolts and splash shield (located under front of vehicle).
8. Remove A/C drive belt and power steering drive belt. Timing Belt Removal
   
   
9. Remove 5 bolts and upper timing belt cover.
10. Remove 2 bolts and lower timing belt cover.
11. Loosen tensioner lock bolt and pivot tensioner pulley outboard.
12. Retighten tensioner lock bolt. NOTE: Mark timing belt for rotation if it is being reused.
    
13. Remove timing belt.

To Install:
Crankshaft match marks

1. Align marks on timing belt pulley and pump body. Camshaft pulley alignment marks
   
   
2. Align marks on camshaft pulleys with alignment marks on seal plate.
3. Install timing belt. NOTE: No looseness should exist on the tension side and at the camshaft pulleys.
   
4. Loosen tensioner lock bolt.
5. Turn crankshaft 2 revolutions in direction of rotation and check that timing marks are still in alignment.
6. Tighten timing belt tension lock bolt to 27-38 ft lb (32-52 Nm).
7. Apply a force of 22 lbs to timing belt between camshaft sprockets.
   • Belt deflection should measure 0.30-0.33 in (7.5-8.5 mm)
   NOTE: Replace tensioner spring if timing belt deflection is excessive.
   Timing Belt Installation
   
   
8. Install lower timing belt cover.
9. Install upper timing belt cover.
10. Install power steering drive belt and adjust belt tension.
11. Install fan pulley.
12. Install generator drive belt and adjust belt tension.
13. Install A/C drive belt and adjust belt tension.
14. Install splash guard.
15. Install fan and fan shroud.
16. Install 4 fan bolts. Tighten to 24 ft lb (33 Nm).
17. Install fan shroud mounting bolts.
18. Install fresh air duct.
19. Connect hose to resonance chamber.
20. Connect battery negative cable.

You need to get a manual. Try the Haynes manual for your car. Try autozone; generally available for around $20-$25. This is not the type of thing that can be covered here in enough detail to do you any good. You need pictures.
General procedure is to buy new timing belt. Make sure cylinder #1 is set at TDC. Disconnect negative battery cable. Remove engine covers to access timing belt and remove timing belt Make sure all components are properly aligned and loosen pensioner to remove old timing belt. Install new timing belt. Tension belt. Double check to ensure all components are aligned properly, replace timing belt covers and reconnect battery.

3.5L Engine

Remove or disconnect the following:

1. Negative battery cable
   

• Engine coolant
  
• Water pump pulley bolts
  
• Alternator bolt, loosen only
  
• Water pump pulley and drive belts
  
• Crankshaft pulley
  
• Timing belt cover(s)
  

1. Turn the crankshaft until the timing marks on the camshaft sprocket and cylinder head are aligned.
   
2. Loosen the timing belt tensioner bolt and turn the tensioner counterclockwise as far as it will go. Tighten the adjusting bolt.
   
3. Mark the timing belt with an arrow showing direction of rotation.
   
4. Remove the timing belt.
   
5. If defective, remove the timing belt tensioner.
   

Timing belt sprocket alignment mark positioning for belt removal and installation—3.5L engine

To install:

1. If necessary, install the timing belt tensioner.
   
2. Attach the top of the tensioner spring on the engine coolant pump pin. Ensure the hook on the pin is facing down and the hook on the tensioner is facing away from the engine
   
3. Rotate the timing belt tensioner to the extreme counterclockwise position. Temporarily lock the tensioner in place.
   
4. Align the timing marks of the camshaft and crankshaft sprockets.
   
5. Install the timing belt on the crankshaft sprocket, then onto the rear camshaft sprocket.
   
6. Route the belt to the coolant pump pulley, the front camshaft sprocket and the timing belt tensioner.
   
7. Apply force counterclockwise to the rear camshaft sprocket with tension on the tight side of the belt and check that timing marks are aligned.
   
8. Loosen the tensioner bolt 1–2 turns and tighten the timing belt to a tension of 57–84 lbs. (260–380 N).
   
9. Turn the crankshaft two turns clockwise.
   
10. Readjust the sprocket timing marks and tighten the tensioner bolts.
    
11. Install the timing belt covers.
    
12. Install the crankshaft pulley and tighten to 108–116 ft. lbs. (150–160 Nm).
    
13. Install or connect the following:
    
    • Timing belt cover(s)
      
    • Crankshaft pulley
      
    • A/C compressor belt
      
    • Water pump pulley
      
    • V belt
      
    • Negative battery cable
      
    • Engine with coolant
      

Technically, nothing else needs to be changed when replacing a timing belt, however it is recommended or suggested to replace the timing belt tensioner and water pump while doing the belt. These items are only accessable when doing a timing belt. The cost should be under $100.00

All of your fan belts needs to be taken off because the timing belt is located beneath the crankshaft pulley. There is a possibility that you may need to lift the motor off its motor mounts to gain access to the timing belt. Remember, the timing belt can't be seen from the outside.