Hard starting?

[Ashman]

Hi all, The other week, I put some 89 octane in my car, only about 5 gallons worth, on top of a couple of gallons of premium that was still in the tank.

Immediately I started having loss of power, and harder starting, and some black smoke on startup, hot or cold.

After the gas was done, I put premium back in, and the problem was gone, no hard starting, no loss of power, no black smoke.

Well after that tank of premium, I refilled with premium again, and the problem was still gone. Buit now even with premium, my car is hard to start. I can crank it, it will engane, but then the engine will die unless I gas it to stop it.

It returns to idle just fine, and I am on my way.

I am thinking I might have a fouled plug, faulty cap, rotor, or maybe a wire.

Or perhaps is it the elusive OVP?

Either that, or the gas station has low octane in their premim pump so they can rip us off.

Whatever the problem is, I'd like to get it resolved.

What do you guys think? I will happily replace plugs, cap, rotor, etc if needed, or even the ovp.

What do you guys think is the cause? Remember this has only happened in the last week to week and a half, and the car did the same symptons with lower grade gas, but now it has high grade and its doing it again.

Alon