Sorry, no picture tutorial but I've still got everything I wrote so the next time I have the cover off my engine, I'll take some snaps
Yup, that's the solenoid cap although that picture is from an Alfa I believe but it looks exactly the same on the Abarth. This is what I recently posted into another thread, might be useful. Test 1 is conducted with the engine off, Test 2 and 3 with the engine running.
1) To test the solenoid: What you're trying to do is to test the variator solenoid, and it's easy to diagnose, just put your multimeter across the 2 terminals of the solenoid (the blobs on the top, not the plug connectors) and check for continuity, if there's none (eg. you've got some resistance there) then undo the 2 philips screws on the top of it and remove the cap (pull it off, don't twist), connect the multimeter to the 2 spikes on the solenoid and check for continuity again, I bet you get it this time. if you do then it's the cap at fault, what you need to do is drop little balls of solder into the 2 holes for the spikes in the cap and then fit it back on, then you should have your continuity back accross the plug terminals. If you didn't have continuity across the cap and the actuator pins, then the actuator is probably at fault and you'll need to get it replaced.
2) To test the
ECU: Take the plug off the solenoid and connect a multimeter to the socket of the plug. There's three there and I can't remember which ones you need to test but essentially, what your trying to do is is see if the
ECU changes the voltage across the two of the pins when the engine goes through the rev range. At idle until about 3500rpm, there should be 0volts. At 3500-4750rpm, there should be 12v and from 4750 to redline, there should be 0v. If you see that happen, then the
ECu is okay
3) To test the Variator: The solenoid has a permanent 12v on one of the pins it but the other pin is only grounded by the
ECU when the variator is to be actuated. This means that you can test the solenoid by grounding one of the terminals (the bottom terminal I think, test this yourself by using the multimeter and testing the voltage between the chassis and each solder blob on the top of the solenoid cap. Whichever doesn't give you a voltage reading, is the one you want to ground). So... with the engine running, briefly touch a wire between the chassis and the solder on the cap that is supposed to be grounded by the
ECU.
If everything is working as it should in the solenoid and the variator then the engine should almost stall straight away. This is because the variator has altered the inlet valve timing at idle meaning that the inlet valve is open at the wrong time messing with the compression and ignition.
