There are few factory 80 down here HZJ80 with A442 and indeed it's slow .. but surprisingly ( at least to me ) they are not really worst than a manual 1HZ 80 ..
2H that's a slow Turtle ( never 80 factory Drivetrain although )
None of those Toyota diesel motors ( even NA ) are really to good about mileage .. specially when you are reving them up ( HW speed ) trying to make them to " perform " well ..
Drop a message to your ISP or hosting provider .. they should take care of your situation.
That happen a lot when using a shared hosting .. in your same server could have a shady spam generator ( or worst ) domain ..