I already changed the main fuel pump. I figured this has come up before but I couldn't locate any info. The noise sounds like high pitched wind - but only occurs when I press on the gas. Let off the gas (at any speed) and the sound goes away. Thank you. 133,000 and counting (bought at 105,000)

bearings, or so I was told before... i couldnt figure it out yet, i am having the same problem... do you get like really disturbing high-pitched voices or rather bearable ones? mine do not sound that terrible.

Lots of possibilities, diff whining on drive, low auto fluid or noisy auto pump, radio suppression not working. Good luck.

Now I noticed that this is a 1990 version. In my old 1979 (now getting to be like new)) a leakage develops at the thumb idle screw, as the screw thread wears, and makes a whistling (whinning) noise. Just a thought but it could be a similar airleak. Its fixed in mine by putting plumber's tape around the thread on that screw.....perhaps that wear continues...in later models?