I have 1982 Porsche 944,its been sitting for 4 years, put new battery,ignition coil and new spark plugs but still have no spark,what component/unit is going to trigger the coil to produce spark?

Not much left unchanged is there and no doubt you have done compression testing on all 4 cylinders as well. (If not you need to). I assume it is cranking over normally with the starter motor but not firing.

I would try one of the Porsche Owners Forums for this as one of the other 944 owners there should be able to help..... Like this one..................

Porsche 924 944 968 Technical Forum Pelican Parts Technical BBS

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https://www.reliable-store.com/products/1982-1991-porsche-944-944s2-944-turbos-951-service-repair-manual

I would take a hair dryer and start to blow dry the coil, all the electrical wires that are attached to the ignition system, is a 12v tester to check primary circuit ( clip the coil + and touch the ground to see if you have elec flow, touch the frame of the car ) if it lit up then I would take the coil to have your mechanic check out if the coil is ok. Then get one of those spark plug wire ignition tester, it just clip on to the ignition wire and turn the motor, just test all 4 wire just to make sure, then the last thing to check is spark plugs, u can remove them but have them rest touching the engine block, turn it over n u shud get sparks going, o/w is the plugs, just replaced them is only like 10-12 bucks each.

to check that substitute the ecm with a known good unit

hello there
it is possible that you need DME control relay.It costs about 20$

proporsche

You injector are plugged,Below the fuel tank is the fuel pump you will need to test this for fuel sitting for ten years the fuel pulsation damper are dried out and you will have to run the fuel pump till the dampner unplugs,turn the key the fuel pump should of been heard if its not electrolyte has already settle in the pump and rendered it useless,you will need a fuel pump

Sounds like you need a new cap and rotor.

Start at the coil. With key in on, the coil should have a hot wire to the primary side of coil. You have the manual-does it show troubleshooting for the ignition system? You will most certainly need an automotive volt tester, a digital volt-ohm meter (DVOM) is best buy, also known as a multi-meter. Doesn't have to be an expensive one either-$30 for decent ones. Use it to test for power at the coil when key is on- that's why they call it the "ignition switch", hey? So if you have power to coil, read up on your ignition system to see how the coil is controlled to deliver spark. On American makes of those years, an ignition control module was used to turn the primary side of coil on and off. Before computers, the ICM was controlled by a pick-up coil inside the distributor to tell the control module where the crankshaft was. So spark would be delivered at the right time.

the most likely cause is a defective crank pick up sensor that is failing when hot = No spark untill cold

check cam belt