well today after i got off work i went out and started my car. My car started and then the like the rpms stayed right around 250 and i gave it some gas and my whole car felt like it was shaking. I poped hte hood (it is still lshaking) the engine was shaking pretty good. I gave it some gas andthe rpms slowly went up. then it all of a sudden went to its purr. it was really wierd does any one know what this means? does it mean my engine is going out? is it seizing? or what let me know i really dont know. Thanks
Oh its a 1990 gxl rx7 na

 

could be as simple as old spark plugs. Tune up lately?