Spark plug closed by engine.

[Yogitech1]

I've put about $1,500 in this Journey of mine. TIPM, PCM and ALTERNATOR replaced, PCM twice both preprogrammed, second one did the job almost, the second pack in the transmission had to be changed also. With the replacement PCM I had no 4th gear and no shifting by throttle pressure. That's all fixed now but, I have a new issue that has us perplexed. I can accelerate quite quickly for a 4 cyl. but, if I have to suddenly get out of the way due to misjudged timing, if I stomp to the floor, I will electrically lose a cylinder and lock in with no acceleration and max rpm around 2,500 or so the tach says. In the past this has slammed #2 spark plug shut but, yesterday the plug slamming didn't happen but, still missing engine. After checking the plug and restarting the engine it ran fine.

Does anyone have a clue as to what is happening. Going back to the spark plug, the 2 times before when this happened for a few seconds it sounded like peanuts rolling around in the engine, this last time I lost a cylinder, no rolling Peanuts and no closed plug.

PS the second PCM had to be reprogrammed at the transmission shop even though it came preprogrammed by the distributor.

Edited April 6 by Yogitech1

[John/Horace]

So it’s the 3.5 timing belt engine I assume.  Still original belt most likely. Either wrong longer spark plugs getting hit or slightly stretched belt/weak tensioner triggering limp mode power loss.  The fact it still ran after piston clipped plug is pretty impressive. Very time consuming complex job to swap out belt and tensioner and usually water pump.

Edited April 11 by John/Horace

[Yogitech1]

Sorry I thought I included that it's a 2.4L engine and before the computer issues it never hit a plug, even if I pushed it to the floor but, now I can't it's like the timing goes wacky at WOT.