last circuit was a 116 (lh 2.4) sorry. Have you tried a timing light?
So point 15 is not getting 12V when measured to ground?
try this from VLVworld.com
Introduction
This section describes the components of the ignition system and how to adjust them. Some tools are necessary for the adjustment procedures and a description of those is also given. You can find and purchase most of the parts described in this page (and some you don't see!) in the following parts catalogue pages from VLVworld.com:
740/760/780 Ignition Catalogue
940/960/S90/V90 Ignition Catalogue
A brief description of the main components and their functions:
Ignition Coil- The ignition coil converts the 12V from the battery into a low current, high voltage charge capable of jumping the spark plug gap.
Distributor- The distributor determines where the charge from the ignition coil is sent. Under the distributor cap is a rotating unit called the rotor which makes contact between the ignition coil wire and one of the spark plug wires. On models before 1988 there is a hall effect sensor inside the distributor. This is wired to the ignition computer and senses the position of the camshaft. Models after 1988 utilise an rpm sensor on the flywheel to perform the same task.
Spark Plugs- The spark plugs each sit inside a combustion chamber. When the timing is right (as noted by the distributor) a current is sent along the spark plug wire. This current will then produce a spark igniting the whole combustion chamber.
Wiring- The coil wire connects the ignition coil to the distributor cap and spark plug wires then run to each plug. These wires are sometimes referred to as high-tension or ht leads. The wiring must be well insulated to prevent loss of current.
Knock Sensor- The knock sensor causes the ignition computer to retard the ignition timing if knocking (preignition) is occurring.
Power Stage- The power stage amplifies the pulses sent from the ignition computer before sending the signal to the ignition coil.
Ignition Computer- The ignition computer or 'control unit' receives inputs from the various sensors and determines the ignition timing. VOLVO ignition computers rarely fail, check all connections and debug the system systematically.
A brief description of tools used with the ignition system:
Spark Plug Gap Tool- This tool is used to measure the spacing between the electrodes at the end of a spark plug. The gap spacing should always be checked- new plugs may not be set for your VOLVO. It should cost under US$5. An alterative is to use feeler gauges, if you have them.
Timing Light- A timing light attaches to the battery and around one of the ht leads. When the trigger is pulled it flashes, corresponding to current sensed in the ht lead. A basic timing light should cost under US$50 from any auto parts store, or a mechanically inclined neighbor may have one you could borrow.
Voltmeter- A voltmeter will enable you to check the resistance of wires, and ensure continuity. More than anything else a voltmeter will help eliminate wiring concerns from ignition system troubleshooting.
Troubleshooting
No Start
Check fuses, connections, battery
Check for a dry coil tower and distributor cap
Use a timing light to check for current in the coil-distributor wire
Check resistance of the coil-distributor wire (ideally 5.6±1 k-ohm/meter)
Check resistance of coil
Primary resistance: 0.5 to 0.9 ohms
Secondary resistance: 6.0 to 9.5 K-ohms
Inspect distributor cap and rotor for damage
Engine Misfires
Irregular- loose connection before the distributor
Regular- Distributor cap, spark plug wires, spark plugs
Check each wire with a timing light
No current on a wire: fault is in wire or distributor cap. Check resistance of the suspect wire (ideally 5.6±1 k-ohm/meter), inspect cap/rotor.
Current on all wires: fault is with spark plug(s). Check or replace each spark plug.
