I have a 86 NA auto, bone stock. everythings good but only ONE problem. Sometimes when i started my car, it revved up to 2500rmp(this part is normal), then it would start dropping to 500 then stall, if i wanted to prevent that, I needed to give it a little gas, then it would be fine. Sometimes it can hold it by itself, sometimes not. Any idea why? thanks

 

bad thermowax or dirty/bad bac

 

^

 

Other thing is something wrong with that engine warm up system, which is a load of ***** and needs to be removed....