I just had a thought regarding my old OM615 motor. Since my motor has an actual throttlebody, what are my risks of a runaway engine? I don't have any warning signs - line from the vac pump to the manifold is clean, doesn't use oil, etc. But, since I have controll of the air entering the engine as well, wouldn't a runaway condition just cause a bunch of smoke but not uncontrollable revs?

__________________
1971 220D/4-speed ~250K mi. Family owned (dads side) through three generations since <5K miles.
1992 Chrysler LeBaron, 3.0V6 125K. Family owned (moms side) through three generations since new.
1977 Chevy Camaro Continual hotrod project
1970 Cadillac Sedan DeVille 472ci and nearly 19' long
1974 Fiat Spider Still needs work