So I’m fairly new to this thread but this cars been a mystery to me and I’ve tried diagnosing the car multiple times I have a decent amount of mechanical experience and I’ve had multiple techs throw in their comments about it too but we can’t find the issue.

I’ve had the car about 2 months now it’s a 97 Honda prelude type SH.

1st issue: So this has been the most common issue the rpms will jump at idle from anywhere in between 900rpms-1700rpms which I believed at the time might have been the IACV so I cleaned it and I bled the coolant and nothing worked

2nd issue: one of the times I was driving on the highway I was having a little bit of fun with it bc I had just gotten the car so I was testing out the VTEC and in 5th gear bc of the tune it tops out at 107mph and it threw a code for VTEC solenoid failure so I took it home checked everything out and it seemed normal so I just assumed I dropped oil pressure but after the 3rd issue arrived I got it home and there were still no codes but it threw it again when I was in the home stretch of trying to flat tow it home

3rd issue: this one was the most recent one I had a crank no start after hitting a bump in the road it was a pretty big bump so I checked timing and it jumped a tooth or two so I took the whole timing components off replaced the water pump, timing belt, balance shaft belt, tensioner and auto tensioner after that the car started up relatively good and I know it’s an interference motor so I triple checked everything to make sure the motor was good and before I had already replaced plugs and wires, fuel pump, belts, checked all my grounds and fixed most of them previous owner mangled a bunch of **** so I went behind and fixed it all but before I realized timing might be off it was having crank no start issues but when it would run it would backfire like crazy, fuel pressure would be normal, but it would die out after like 10 seconds of it fighting on its own with no CEL or pending codes

4th issue: this is the most recent one I still haven’t gotten everything 100% but timings good but when I was taking it for a test drive about a few days after running it and bleeding all the coolant again bc I just replaced the radiator too since there was a leak now the rpms just completely cut out the cars still on and driving but rpms suddenly tank to zero then cut back on but it’s been shutting off on its own now and it’ll start back up just fine but rpms are bouncy again and idles been **** again and sometimes I can feel small explosions in the catalytic converter which has never happened before

I’m madly in love with this car but I just want to find out what the issue is with the car I’ve diagnosed just about everything I can think of besides internally and a few sensors here and there but to my knowledge clutch is fairly new so it shouldn’t be slipping and the timings not off either so I’m completely at a loss with this car.