Hello. Tried a search but couldn't find anything that sounds like my situation. So my 84 z28 runs terribly-like it's only running on one bank. This just started yesterday. The first time, I thought I was running out of gas. But it seems to happen any time I'm under quarter tank. If I add gas, she runs fine-until the next time it drops below a quarter. I have 2 theories on this. First, the car sat 2 days and it's been raining a lot. Water in the tank? I plan to try seafoam with a fill up. Can't hurt anything. Second, maybe a failing fuel pump? It also seems to bog more when going uphill. Any ideas? Thanks in advance.

 

Maybe the sender and/or fuel guage is not reading accurate, and you don't have a 1/4 tank left - maybe you are running out. When it gets to the 1/4 tank mark on the guage, fill it up completely, and see how many gallons it holds. We have a +/- 15 gallon tank, so if it takes close to 15 gallons, then your not at 1/4 tank, your empty.

 

Thanks for the reply. Gave that a shot. No dice. Filled the tank, put in a can of seafoam, changed the fuel filter, and as a precaution sprayed out the carb. Still does it. Yesterday, I thought i may have figured it out, but apparently not. With the air cleaner off and the engine running, I noticed the choke wasn't fully open. So I adjusted it. Car ran normal for a few minutes. Then it acted up again. So I leaned the choke out some more. Ran fine for about 20 miles. Then...back to the same problem. I also noticed when it starts running bad and the bottom drops out, it will sometimes backfire from the rear of the exhaust. Exhaust backfires are a result of a rich condition-correct? So, the car is drowning in fuel. But why? The carb is brand new. Only been on there about 2 months. Ran great before. The only thing I can come up with is the weather changes here. It's significantly colder now. I may need to adjust settings-but what? Am I on the right track? Any help would be greatly appreciated. My commute to work is awful as a result. I should also say the issue seems to appear after driving for a while. It is usually absent upon startup. Thanks