Diffuse upstream ions at low energy (~1.6 keV) fluctuate rapidly compared to higher energy ions and vary in intensity in a systematic way with ϕ, the angle between the interplanetary magnetic field BI and the earth-sun direction. The 1.6 keV ion intensity is highest when ϕ is in the range 60¿ to 90¿, and these ions may nearly disappear for values of ϕ near 0¿. There is a rather narrow energy range in which the flux remains remarkably constant. At times this energy interval may be centered at an energy as high as 30 keV and at other times as low as 6 keV. This energy appears to vary systematically with the angle ϕ. We have also found that few ions scatter out of the foreshock onto less disturbed interplanetary field lines upstream from the foreshock boundary. Finally, we have found several events in which diffuse ions with energies at least as high as 60 keV are present on field lines that make angles up to 60¿ with respect to the earth-sun direction. In these cases a first-order Fermi process would have only about 3 minutes to increase the energy of the upstream ions. Energization at the bow shock may provide the required additional acceleration. Intermediate upstream ions of 60 keV energy appear even at ϕ angles up to 80¿.