Hey Norman, welcome to the SS Forums. Please put your city/state in your sig so we know where you are. Your posts will be locked if you don't fill it out.
Now to your starting problem. There are MANY different possibilities here. If you have to give it glow when the engine is hot, it may be a sign that your injection pump is worn out. When the pump is cold, the tolerances are tight and it develops adequate pressure to pop the injectors. When the pump gets hot the tolerances loosen up and the pump can't develop enough pressure to pop. Adding a quart of oil to your diesel can help. Also, if the engine has a bunch of miles on it, the timing chain loosens up and allows the timing to go more retarded I believe. You can compensate for this by loosening the pump mounting bolts and advancing the timing SLIGHTLY. Taking it to a diesel shop and having it timed is a good idea too. Slow cranking speed can also cause poor starting. There is a minimum cranking speed to get the engine fired off, I think it is in the neighborhood of 750rpms, check the Hayne manual. Your starter motor could be getting heat soaked after the engine shuts down and airflow ceases. That will cause a worn starter to really drop off speed. A gear reduction 24v starter is available from Delco and is a great addition. What type of plugs are you running? Are you using the original glow relay and power supply thru the resistors on the firewall? The resistors should have 24v going to them. They step the voltage down for the plugs, but keep the amps high. There are also plugs which are 6 volt slow burn, 6 volt fast burn, 12v fast and slow, etc... That makes a difference because the civvy blazers used all kinds of different plugs over the years. I had really good luck with the AC13Gs.
Please fill out your sig and in your next post, tell us all about your truck like age, mileage, rebuild dates, etc... so we can help you better.
