[Mrmerlin]

after checking the grounds as Chris points out,
NOTE there may also be some at the back of the V,

I would do a firefly test,
remove the intake tubes and run the car at night look for jumping sparks,
if you see any then a new set of wires is called for , and it probably wouldnt hurt to add them to the engine now

Make sure the coil wires are not touching any metal parts as they will rub and short out.

Get the MAF rebuilt, this will do wonders for drive ability.

Get the injectors cleaned.

Check the timing of the twin dizzy replace the belt if necessary.

check the timing of the cams / crank/ dizzy

replace the temp 2 sensor and possibly the Bosch plug that connects to it.

clean the grounds at the chassis and behind the right Q panel in the hatch floor.

for the high idle it may need to be turned down after correcting the vacuum leaks.

I know I have added a lot of things to do here,
BUT if you dont want to see this car again,
then all of the pieces parts must be in top condition for continued performance,,
so often only one or two of these parts gets repaired and the engine still runs but not well,
now its running like shmack so you have to restore all of the critical components