1994 GMC Suburban Owner's Manual - Page 75

lf Your Diesel Engine Won't Start If you've run out of fuel, look at "Running Out of Fuel" (see "Diesel Fuel Requirements and Fuel System" in the Index). If you're not out of fuel, and your engine won't start, do this: Turn your ignition key to RUN. Make sure that the "GLOW PLUGS" light is out. Then turn the ignition key to START. If the light doesn't go off, wait a few seconds, then try starting your engine again. And, see your dealer as soon as you can for a starting system check. If the light comes on and then goes off and you know your batteries are charged, but your engine still won't start, your vehicle needs service. If the light does not come on when the engine is cold, your vehicle needs service. If your batteries don't have enough charge to start your engine, see "Battery" in the Index. Be sure you have the right oil for your engine, and that you've changed the oil at the proper times. If you use the wrong oil, your engine may be harder to start. If the engine starts,runs a short time,then stops, your vehicle needs service. Engine Coolant Heater (Engine Block Heater 4 2-19