Fuel issue?
 

I've read and searched the forums with no luck. I'm hoping you can help.

I revently bought an 04 rx-8 auto. The engine's been replaced.

Car runs great... except when it doesn't.

Typical symptoms start when I'm at about 1/3 tank, and often goes away when I fill it with super. At 1/4-1/3 tank, it sometimes runs fine, but more often, it shakes, sputters and stalls... then won't start easily. Seems especially to be a problem in stop and go traffic. I take care to rev the engine before shutting it off and try and run it until it's warm. Unfortunately, with such a small gas tank and being in Texas, I'm having to fill it every few days to keep it from falling below half a tank.

Any suggestions would be helpful, especially those that are relatively easy and inexpensive. It SEEMS as if there is some gunk in my gas tank?

More info on the car; mileage and any service done?

78,000 miles. All service up to date as of purchase date. Engine replaced at 60,000 miles +/- new coils etc at that time. oil changes only since. I've only had it for a few months.

The odest thing was the other day when it started and stalled... wouldn't start no matter what. Pushed it 50 feet, it started right up but shook/shuttered on occassion.... used "manual" mode to keep the revs high and kept the idle up so it wouldn't stall. Drove it to gas station, filled it up, ran perfectly.

Likely the fuel pump....

Yeah i would look into a new fuel pump. Did you get any type of warranty when you bought the car?

Fuel Pump
http://www.finishlineperformance.com...cat=338&page=2

Fuel Pump Mounting O-Ring
http://www.finishlineperformance.com...cat=338&page=2

Also i would buy some BG44K http://www.finishlineperformance.com...cat=338&page=1

Interesting. Thank you for the advice. Is that something that does "worse" when the tank isn't full? Forgive my ignorance.

if you are gonna go with a new pump, get the bhr one