Hello, first time starting a thread on here.

I have a 99 4runner limited 3.4 automatic trans 4x4 with about 256k miles. I have had the rig for about 6years now and it's always been a great and reliable vehicle. I have gone allot of awesome places in my 4runner. Towards the start of the new year it started giving me some problems, Rough idle and misfires. After chasing problems and throwing parts at it I finally figured out it was a injector failing along with the fuel pressure regulator. I got that fixed and she's been running great. So this leads me to a new minor issue.

I don't drive her very much nowadays, pretty much just a weekend camper/hunting rig and grocery getter now. Occasional when I go to start it hot or cold I get a slightly longer crank time and the battery light on the dash flashes a few times then it turns over. The battery light only flashes when I'm starting it and goes away as soon as the engine starts. Today I took a multimeter to my battery and alternator and they seem to be within the specs they should be. After surfing the web for a hour I decided I would check the electric connections and grounds. What I found is the ground that goes from the back of the engine block to the fire wall was pretty saturated with oil and road grime. I cleaned up the connection point on the block really well and also cleaned the wire too. I reconnected the ground and started it and she turned over really smooth and quick. But like I said it only does the rough start and flashing battery light every once in a while. The problem could still be there and it just hasn't had a opportunity to present itself.

So my question is, do you guys think a dirty/bad ground connection could cause a occasional rough start and flashing battery light? What other parts do you think I should check?

I know this is like finding a needle in a hay stack but any suggestions would be appreciated.

List of parts replaced in the past 6 months

Spark plugs
Ignition coils/wires
Upstream/down stream o2 sensors
Fuel filter
Fuel pressure regulator
Fuel injectors
Oil/oil filter
Air filter
Cleaned MAF

Starter is new, about 12 months old.

I know there's a few other parts I replaced but can't think of them at the moment.

Thanks guys, I love this forum by the way. I have been lurking around on here for about 6 years now and this is my first time starting a thread.