Hi, Sure it could have been the fuel, a good car is like a good horse, both need to be exercised. I use Lucas fuel additve frequently, it cleared up an injector problem on my 88, I put it in all my vehicles, the 99 Vette has only 8000mi. on it and is in new condition. I found on my 88 the the base engine timing was never adjusted, a connector that has to be dis-connected to set base timing still had the factory tape on it. The timing was off 6 degrees, it made a world of difference when I set it properly. You have my cell number, we should get together for a coffee somewhere and compare notes, by the way, my name is Joe Arnone. See Ya