# New gas issues



## WDMelvin (Jun 23, 2014)

If there is a thread about this already, please point me toward it. Again , I have a 70 GTO 400 4 speed car of my dad's that I work on. He was wondering how to tune it for newer gas. Seems like it is running terribly rich. The exhaust smell in the garage after starting or parking is strong with a slight tinge of fuel. I've gone through the entire fuel system from tank to carb and there are no leaks at all. We were wondering if the newer fuels don't quite burn all the way and will give this kind if issue? I don't think the carb is adjusted correctly and is rich right now due to the black exhaust pipes. It does not appear to smoke black out the back but I put a new a tank and sending unit in it and it is drinking gas like it is going out of style. We were told that the engine was retarded a little and I checked the timing but I may not have had the rpm down low enough (about 675) to get past the mechanical advance which may explain lots of fuel use but I need to further investigate what the timing actually is. I checked it and it was off the scale showing maybe 15-16 deg BTC but it never would knock/ping or start hard. If the sending unit is working correctly, I checked it full and empty before I installed it, it has used about 3/4 tank in about 100 miles. Yikes! I guess I'm looking for input on how to tune for the new gas to get complete combustion and why it is eating gas. To my knowledge we are at the stock CR of 10.5:1. Thanks.


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