Chrysler Caravan/Voyager/Town n Country 1984-1995

Ignition Timing

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Basic timing should be checked at each tune-up in order to gain maximum engine performance. While timing is not likely to change very much with electronic ignition systems, it becomes a critical factor necessary to reduce engine emissions and improve driveability.

A stroboscopic (dynamic) timing light must be used, since static lights are too inaccurate for emission controlled engines.

Some timing light have other features built into them, such as dwell meters or tachometers. These are nice, in that they reduce the tangle of wires under the hood when you're working, but may duplicate the functions of tools your already have. One worthwhile feature, which is becoming more of a necessity with higher voltage ignition systems, is an inductive pickup. The inductive pickup clamps around the No. 1 spark plug wire, sensing the surges of high voltage electricity as they are sent to the plug. The advantage is that no mechanical connection is inserted between the wire and the plug, which eliminates false signals to the timing light. A timing light with an inductive pickup should be used on electronic ignition systems

ADJUSTMENT




CAUTION
Always apply parking brake and block wheels before performing any engine running tests.

2.2L and 2.6L Engines

See Figures 1, 2, 3 and 4



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Fig. Fig. 1: Timing mark-2.2L engines



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Fig. Fig. 2: Timing mark-2.6L engines



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Fig. Fig. 3: Typical timing mark window



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Fig. Fig. 4: Checking the timing with a timing light and adjusting by turning the distributor

  1. Clean off the timing marks.
  2.  
  3. Mark the pulley or damper notch and the timing scale with white chalk or paint. If the timing notch on the damper or pulley is not visible, bump the engine around with the starter or turn the crankshaft with a wrench on the front pulley bolt to get it to an accessible position.
  4.  
  5. Connect a suitable inductive timing light to number one cylinder plug wire.
  6.  
  7. Connect a tachometer unit with the positive lead to the negative terminal of the coil and the negative lead to a known good engine ground. Select the tachometer appropriate cylinder position.
  8.  
  9. Warm the engine to normal operating temperature. Open the throttle and release to make sure the idle speed screw is against its stop, and not on fast idle.
  10.  
  11. On vehicles equipped with a carburetor switch, connect a jumper wire between the carburetor switch and ground to obtain specified rpm. Disconnect and plug the vacuum hose at the Spark Control Computer (SCC). (Refer to the specifications decal under the hood for specific instructions).
  12.  
  13. Read the engine rpm on the tachometer's 1,000 rpm scale, and adjust the curb idle to the specification noted on the under hood label.
  14.  
  15. Aim the timing light toward the timing indicator, and read the degree marks. If the flash occurs when the timing mark is before the correct specification, timing is advanced. If the flash occurs when timing mark is after the correct specification, timing is retarded.
  16.  

Models equipped with the 2.2L engine have a notch on the torque converter or flywheel, with the numerical timing marks on the bell housing. Models equipped with the 2.6L engine have the timing marks on the front crankshaft pulley.

  1. If adjustment is necessary, loosen the distributor hold-down screw. Turn the distributor slowly (while observing the timing marks with the timing light) until the timing mark is correctly aligned to the specified value. Once the timing is correct, tighten the hold-down screw. Recheck the timing and curb idle speed. If the curb idle speed has changed, readjust it to the specified value, then reset the ignition timing. Repeat the curb idle setting, and ignition timing until both are within specification.
  2.  
  3. Disconnect the timing light and install all vacuum hoses, if necessary.
  4.  
  5. Turn the engine off, then remove the jumper wire and tachometer.
  6.  

2.5L and 3.0L Engines

See Figures 5 and 6



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Fig. Fig. 5: Timing mark-2.5L engines



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Fig. Fig. 6: Timing mark-3.0L engines

  1. Clean off the timing marks.
  2.  
  3. Mark the pulley or damper notch and the timing scale with white chalk or paint. If the timing notch on the damper or pulley is not visible, bump the engine around with the starter or turn the crankshaft with a wrench on the front pulley bolt to get it to an accessible position.
  4.  
  5. Connect a suitable inductive timing light to the No. 1 cylinder spark plug wire.
  6.  
  7. Connect a tachometer unit, positive lead to the negative terminal of the coil and the negative lead to a known good engine ground. Select the tachometer appropriate cylinder position.
  8.  
  9. Warm the engine to normal operating temperature.
  10.  
  11. With the engine at the normal operating temperature, disconnect the coolant temperature sensor. The radiator fan and instrument panel check engine lamp should come on. (See specifications decal under the hood for specific instructions).
  12.  
  13. Read the engine rpm on the tachometer's 1000 rpm scale. Adjust the curb idle to the specification noted on the underhood label.
  14.  
  15. Aim the timing light toward the timing indicator, and read the degree marks. If the flash occurs when the timing mark is before the specified value, timing is advanced. If the flash occurs when the timing mark is after the specification, timing is retarded.
  16.  

Models equipped with the 2.5L engine have the timing marks visible through a window on the transaxle housing. Models equipped with the 3.0L engine have the timing marks on the front crankshaft pulley.

  1. If adjustment is necessary, loosen the distributor hold-down screw. Turn the distributor slowly to specified value, and tighten the hold-down screw. Recheck the ignition timing.
  2.  
  3. Turn the engine off. Remove the tachometer and timing light.
  4.  
  5. Connect the coolant temperature sensor.
  6.  

Reconnecting the coolant temperature sensor will turn the check engine lamp off; however, a fault code will be stored in the SMEC. After 50 to 100 key on/off cycles the SMEC will cancel the fault code. The code can also be canceled by disconnecting the battery.

3.3L and 3.8L Engines

The 3.3L and 3.8L engine use an electronic distributorless ignition system. The ignition timing cannot be changed or set in any way.

 
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