I have a 1995 Geo tracker, and lately when i stop at red lights and the such or if i idle to long the car vibrates and the RPMs drop to almost nothing. I haven't had it stall yet but its gotten close. A buddy of mine is a mechanic and he thinks that the alternator has a bad ground connection. I don't know much about cars. Is he right or could it be something else? I replaced the spark plug wires and cables as regular maintenance so i know those are good. I also got a new battery to try and solve this problem but it didn't work.
How many miles?
Do you do any highway driving or almost all city?
Mostly City, the poor thing has a top speed of 65 on a good day. however I've been able to get all the way up to 80 on a downhill with no wind haha
A rough idle could come from a dirty MAF (Mass Air Flow) sensor. You should also clean the throttle body. And, if the vehicle has, as I think it might, an IAC (Idle Air Control), often attached to the throttle body, that, too, should be cleaned.
So, that's one set of possible interventions.
You might also have some sort of EVAP leak. So, check all hoses and clamps, in-and-out of the engine. Even a small leak would have a negative effect.
These are the easiest and cheapest things to do. See the videos: (The IAC video is for a Toyota, but the procedure should be similar on your Tracker).
https://www.youtube.com/watch?v=NWCKvU2FmDc
https://www.youtube.com/watch?v=VOUB1UiDkKc
Thanks for the ideas, now i have a set list of possibilities to go through and check. I'll end up doing all of them anyways just to be safe.
its mind blowing you still have a 25 year old Geo Tracker on the road
It's a dream to drive it, i bought it because my dad had a purple one when i was younger. He eventually sold it because my mother thought it was unsafe.
Well, then have him diagnose & fix it for you. Don’t you trust him?
I do, however although he is a mechanic we now both work at the same place. We're both mechanics for a medical manufacturing company. He's a good friend and a great mechanic but I prefer to do all my car work myself and only bother him when i need help. My dad was a mechanic and being foolish i didn't learn from him all i should've. I lost both my parents a year after graduating highschool in an accident, so now i try to do all my own car work and maintenance even if i'm not that good yet. My friend, Jesse btw, understands that. I'm not a stubborn man, but i at least give things a shot before handing them over.