17 hours ago, Joja2k said:

PS. while idling, the timing jumps anywhere from 3 degrees all the way to about 10 degrees, but as I press the gas pedal, it starts jumping all around.

Uhm, I think I don't see nor hear any issue, tbh a lower quality coil or a misadjusted dis gap will cause this. Heck, my mpi jumps around +- 3deg

The following is just my info that may or may not be of use to you and may or may not be directly relevant to your current issue. For 30+ years I did run old (20-50 years old) "classic" cars for daily, work, short and long commutes, UK and European holidays and club events so I do have experience of this if nothing else.

When I used to be on a "classic" forum, for about 10 years, things that would often appear about this subject were -

• reverting back to previous old distributor from poor quality new electronic distributor (or back to traditional contact breaker sets from electronic contact breaker points kits)

• faulty (often intermittent) poor quality new rotor arms

• faulty poor quality new high tension leads

• faulty poor quality cheap new spark plugs

• (all of above could have been bought as kit package or individually)

• poor electric contacts or wiring that has been overlooked, sometimes just needing a clean, securing or repositioning

• poor quality new testing equipment

• with Haynes or any other manual it has to be considered when it was written and that it deals with factory standard car and parts

• often road test were not (or could not) done to see how the engine actual goes, feels, sounds, smells rather than just relying on book figures (which are usually a good starting point) for a car or engine that is old and used with a perhaps a mixture of old and new parts which perhaps have yet to bed in with each other.

Not all new ignition parts are poor quality and/or have faults but the quality could be very hit and miss and the faults and problems with them might show up straight away or with some use, often not much use because many of those cars got very little use so it could be quite a while after the part was fitted. I bought an excellent fully (top and bottom) electronic distributor which was on the car for 14 years of my use (still on the car now as far as I know) never needed adjusting and never played up - but it was about five times the price of the very intermittent quality cheap alternatives.

When the cheap alternatives were fitted by other owners many would also carry the old distributor in the boot as an emergency swap repair, I preferred to fit and forget good and reliable parts (when you could get them) and not carry any spare parts, same as I and others wouldn't with a new car.

Good luck.