Honda civic 97

Lately my car shows on the tachometer 0,5 in P, normally its close to 1 in P. It goes almost to 0 and then the "check engine" lights blink once and the techometer goes up to close 1,5(the engine giving gass itself), and again goes back to close 0 and repeats. And while driving the the check engine light blinks once or twice every 30 sec to 2min.

Is it maybe a problem with the Emission Control System?

 

Does it drive OK, just not idle steady?

If that's the case you would start by cleaning the IACV, check that the cooling system is full (look in the radiator, not just the white plastic tank, when the engine is cold), and adjust the valves.

If it also misfires / shakes while driving, especially when you step on the gas pedal hard, that is likely weak sparks. Replace the plugs, wires, cap/rotor in that order if you don't want to spend the money on all at once.

 

I have cleaned the IACV, changed plugs, changed cap/rotor 2 months ago and no change. I have noticed that it happens when the motor is warm. When I start it up in the morning it has no problem, but 10min in it start with the problems, but now its gotten alot worse.

It now can blink over 10 times in 1 minute, and when giving some gass with high rmp it blinks almost all the time. When its blinking the car "shakes". When a blink happens the rpm lower quicly and goes back up again and result for the motor to shake because of sudden rpm change. Normally it blinks 6 times in a row so it rpm goes down and up again 6 times. Any chance of knowing what might the problem be?