I've made a few posts in this group before and got some very good advice, so here's the question;
Recently purchased '95 Chevy High Top Van (G-20) with 350 motor (at least that's what the label says inside the engine compartment). Not sure about the transmission model, although it has overdrive (automatic, of course).
I've changed the rotor and cap, added new spark plugs, and advanced the timing as far as I dare. Also changed the O2 sensor ($60 just for the sensor, ouch!).
This thing starts quick and runs very smooth, no misses or pings, but the spark plugs DON"T have that 'tan' color you get when your burning the right fuel mixture, which makes me suspicious. Instead they are nearly WHITE, which means its running too lean, and seems to confound the mystery (at least to me).
Now the biggest problem. It only gets 11-12 mpg, and that's on the highway. Around town it gets 10, maybe 11 (I've checked it twice). I know this is a high top, so they tend to be a little heavy (4800 curb weight last I checked) and not the most aerodynamic of vehicles, but I've owned vans with 350"s before (it's been a few years) and I don't remember the mileage being _that_ bad.!!
Or am I asking for too much!??
Sorry about the long post, Just wanted to make sure you had all pertinent info.