Why does my 1988 Honda Accord lx excelerate when I first crank it up

My car excelerates 1 minute after I crank it I pat the gas then it goes down to 1 and half
RPM then 30 seconds later it does the same thing and I repeat the same thing of patting
the gas peddle  and it goes back to 1and half RPM it will not excelerate again untill I cut
the car off and start it back up this happened every time I crank ,y 1988 Honda Accord
LX it is a 5 speed 4cyl