Hello guys
I've got a 1990 LTC II with 302 EFI DURASPARK
Last year I started noticing that when I lift the acceleration pedal during cruising it feels like twitching and bumping. I have replaced the intake manifold gasket, but it didnt work.
Then I changed rotor and cap, high voltage wires and sparks. Not a single change.
During the year it seemed to get worse - I have clearly heard the misfire sound from the exhaust.
Then this spring I SUDDENLY wanted to test the new stroboscope, and attached it to this running motor... and i saw certaing misfiring! It was truly certain with exact sound from exhaust pipe after I saw the missing blink of the stobe eye.

So.
- I have changed the control module.
(Meh)
- I've changer the Hall sensor (gee, that was dirty and long)
(Double meh)
- I've took out the brains and resolded the capacitors
(Began to work smoother but the same problem is like HELLO THERE)

Then it was summer and i suddenly found out that the warmer it gets, the worse it works.
When it was hot, like +30C the engine started, rumbled and died in like 1 minute. Once i managed to travel a bit, but it cut off in the middle of the highway and it took me like half an hour to start it again.
Besides, lately it was +5C and the engine started nice and sweet, no signs of problem. Then in 10 minutes it strted rumbling and misfiring.
Also! I can hear the sound like it's crunching candy when working this way. When it's nice this sound doesnt appear.

I've seen smt about "Double grounding and issues with diode in the alternator when warming up" on necro-posts from 2005, but no exact details on where to look. I've dropped extra grounding to the engine, but it didn't seem to make a day.

Please help me with your experience.

 

Did you change the coil?

 

Yes, yes I did, I didnt mention it in the text, srry, just forgot. Of course, I've changed everything that was in Original Lincoln Manual about the igninition

 

So hey, here's the video of it working after veing warmed up
You can definetly hear the "candy crunching noise" from the engine, that appears only with the problem, and the misfire on the exhaust, like BUM
I have a suggestion that this is an alternator issue, cause the noise comes from it's side, but i can't tell 100% because engine is loud and noisy itself

What's your opinion?

 

Here is a video of cold engine work

 

 

The oil pressure has to be less than 3-5 PSI (I think) for the red oil light to turn on. That is not a good sign. Combine that with the noise from the engine when warm points to a serious internal problem. You could verify the oil pressure using a mechanical gauge, and probably should do so before tearing the engine down.