Chevrolet Repair: 1992 Chevy S-10 Blazer, 4x4, 4.3 Liter, 6 cyl., fuel pressure regulator, vacuum line

Question
It had been spitting and sputtering a bit, but once you ran the engine hard enough to maintain 64 and over, it wouldn't do it anymore. I hadn't had any trouble like this for a half a week and then it died the other day while driving down the highway. It will crank, but it wont run. Sounds like it might not be firing. Fuel Pump is new and still working. Thoughts of the timing chain have crossed the families mind. What do you think?
Thank you for any help you can give,
J.

Answer
A quick way to check the timing chain is to remove a valve cover and see if the rocker arms are moving. I am thinking fuel pressure regulator. Are the injectors spraying? pull the vacuum line off of the regulator and turn the key on. Is the pump running? Is there fuel spraying out of the place where the vacuum line was removed from? If the pump is running and there is fuel comming out of the regulator then there is your problem. Go back to basic's. You need 3 things for an engine to run. Air, Spark, Fuel. Start with Spark pull a plug and put it on a ground such as the block. Crank the motor and see if you are getting a good blue spark. Then check the regulator and see if you have fuel spraying out of the throttle body injectors. If this all checks out pull the valve cover and see if the rocker arms are moving.