Mazda 3 - unexplained stalling

[jeppsG8]

Time to turn to the experts here. Problem is absolutely owning me.

2008 Mazda 3s - 2.3l - 5 speed - 75k miles

While driving, the car will lose power (engine not electrical). Feels like I lift my foot completely off the throttle. Depending on how high the RPMs are at the time, it will either drop 1.5-2k RPM and then pick up again abruptly and 'slam' forward. If the RPMs are 2k or below it will usually stall out completely. I can always depress the clutch and restart it immediately. It does this now about every 20 - 30 seconds and doesn't matter if I'm at highway speed, or 25 mph. Gear doesn't matter. A/C doesn't matter. No CE or Codes being thrown.

Power is very normal before and after 'stalling'. Closest thing I have felt like this before was hitting a speed governor on other cars where the fuel gets cut momentarily until the speed drops.

Now, here is the part that is owning me. First thought is that the fuel pump is failing electrically. However I wanted to first rule out the MAF Sensor. I cleaned it (same problem). I disconnected it and the car runs albeit poorly, but it never stalls or loses power. So suspecting bad MAF, I replaced it with brand new and cleared the codes that appeared from disconnecting MAF. Immediately the same problem. I've replaced the fuel pump relay and checked/replaced/cleaned the intake, air filter, throttle body. Car is completely stock.

Any ideas would be helpful.

Thanks,
Brandon

[jeppsG8]

Finally fixed. Fuel pump was failing intermittently. New fuel pump fixed it. Strange behavior but what do you do.

[Chevelleguy]

I really like my G8 and am working through solving a number of issues that were not mentioned when purchased and when solved, will make it a great driver. It is a 09 GT, stock, and 55,000 miles. For the second time, the car has lost all power at highway speed. Once at about 60 mph and yesterday at approximately 80 mph. The engine will die and I have to coast to find the safest area to pull over. The first time, about two months and 3,000 miles back, the fuel gauge showed 1/4 tank. The car would turn over but not fire off just as it would if out of fuel. I walked to station , purchased 2 gallon can and after fueling, car started instantly. Assumed sending unit was bad and until I could replace it, I never let it get to the 1/4 mark. Drove the G8 700 miles from MS to Orlando with no issues. Yesterday, returning home, on I-10 at 80 mph, it died again. Fuel gauge read between 1/2 and 1/4. Trying to restart it brought the same (out of fuel) results as before. After about five minutes of sitting and trying to determine options, it started and ran fine. Filled with fuel and it only held 12 gallons which corresponded with gauge. This is similar to jeppsG8's issue. Has anyone else experienced this and solved it? Check engine light never came on. Have not checked for a code. Thanks