Set the Base Ignition Timing

** The pictures below are from the 165 but the procedure is the same for all GT4s **

Why do I want to check my ignition timing?

To ensure that the base ignition timing for the engine is set correctly. Also if you have running problems then it is also a good idea to verify that the base timing is still correctly set.

If you are suffering from power loss, detonation or errors e.g. code 52 - knock sensor then this might be a good starting point.

What if my timing is wrong?

If your timing is too far retarded then your performance and mpg will suffer. If you timing is too far advanced then you may end up with detonation and damage your engine.

Okay, how do I set my timing?

Before you start the car, locate the crankshaft pulley, (lhs engine bay near the alternator). Turn the engine over, (either by cranking it over or turning over by a socket on the crank pulley bolt), until you locate a small notch in the pulley. Mark this notch with a dab of Tippex/white paint. Note also the small scale/timing indication on the cambelt housing...
  Start the car and go for a drive to thoroughly warm the engine through. This will ensure that the ECU will not alter the timing due to a "cold engine"
With the car at idle verify that the speed is 700-800rpm once correct then locate the diagnostics connector... the diagnostics socket and bridge together T & E1, (TE1 and E1 for 185 and 205).

Failure to short these pins together will ensure that you do not set the ignition timing correctly!
Connect your timing gun signal lead to No 1 spark plug, carefully noting the orientation of the connecting lead (arrowed), and then connect the negative and positive to the battery
Point the timing gun at the crank pulley and your freshly painted Tippex mark. The notch should line up at the 10 deg mark, if this is correct then job done, your timing is correctly set, if not then proceed as follows:
Locate the distributor assembly. You'll notice that the whole assembly is bolted to the block with 2 bolts. Loosen these but do not remove the bolts. Leave the bolts in place so that the whole dizzy can just be rotated by hand. Rotate the dizzy slowly until the notch aligns with the 10 deg indication on the crankshaft pulley
  Carefully tighten the dizzy securing bolts and re-check the timing as it has a habit of slipping when the dizzy is re-tightened. The bolts should be torqued to 39Nm


This article is intended as a helpful guide as to how I verified/set the ignition timing. If you are in any doubt, or not qualified, do not undertake this maintenance, consult a qualified mechanic. Altering the design of the car from the manufacturers specifications is not recommended, always consult the manual.