Master Acceleration Diagnose and Fix Car Sputtering

I suspect the bad gas mileage is because your car is getting warm physically, but the ECU thinks its cold. You may also have some leaky fuel ... Bad gas. Drain and replace. You either filled up with tainted gas, or it has been sitting. Troy. '67 Coupe, built 289 C4 ... After servicing the tranny I drove the car and found that it seemed the transmission was fine but it was an engine problem. It really struggles ... Try increasing engine speed slowly in neutral, and if it starts to miss at the same RPM as 65 mph it may be too much vacuum advance. I had that ... Now my car sputters on acceleration, especially when it first starts. I've been reading various threads (https://www.mgexp.com/forum/mgb-and-gt-forum.1 ... As soon as I get about 35% throttle it will start to sputter and spit out the exhaust. Side of turbo A/F are rich at this point around 11.8. Have you inspected the main relay? Maybe a solder joint is going bad. As for where to put a Fuel Pressure gauge, You could put it on top of the ... A Direct Scan file would probably answer this perfectly because the BLM matrix pops out right away. Any chance you know someone with Direct Scan ... Could be as simple as dirty spark plugs or spark plug gap. If you are note getting any "check engine" light on the dash, chances are you won't ... My Jeep YJ runs great when I accelerate very slowly. If I try to accelerate quickly, it starts to sputter, and the check engine light will sometimes come on.