I have a problem with my car, I have a 92 LX, when I start it every thing is fine and after a couple of minuets of driving and I stop at a stop light then for some risen the RPM goes down the battery goes down almost like it wants to tern off, I pull over to check it, I disconnect the battery thinking that the alternator wasn’t working properly, but that wasn’t it, so then I tern off the car then start it and it goes back to normal. I did a tune up new sparkplug, sparkplug wire, etcetera.???