Cadillac Repair: caddi issues, fuel pressure regulator, coolant temp

Question
Hi I have 2 concerns with my 1999 cadillac sls that I just purchaced, My first concern is that after I quit driving My car, antifreze starts to come out of the radiator cap rapidly, with the radiator cap securly on the car.  What is causing this? The car is not overheating it usually varies between half way and three quarters to being hot and my radiator fan is working as well.  My second question is sometimes when I start my car it dont start immediatly it will continue to turn over but not turn on.  but once I get it started it usually starts up right away.  What is causing this and what should I do?

Answer
Hi Adrian,

       With the coolant issue I would replace the radiator cap with the engine cold and see what happens after it heats up and gets shut off again. The pressure spring could be weak. The coolant temp. could be hotter than the gauge is showing and someone would need to use an infra red thermometer to check the coolant temp. to see if the gauge is accurate. Also check to see what the protection level is. If it isn't around -34 degrees F then that can change the boiling point. Maybe it is more like 0 or a positive number in which case the coolant needs to be drained and 1 gallon of straight coolant added.

      What you are experiencing here is fuel pressure draining back either into the tank through the fuel pump, a leaking injector or a hole in the fuel pressure regulator. If the fuel rail doesn't hold pressure then it takes longer to prime the lines and injectors before the engine starts. The most likely candidate is a bad fuel pressure regulator and the way to check it is to run the engine and then shut it off. The reg. is located under the top engine cover and once it is removed remove the vacuum line and see if fuel is coming out. You might need to run the engine for a minute or two but watch for fuel and shut it off immediately if fuel is seen and then replace the regulator.

     If you bought the car from a dealer/used car lot I would go back to them and explain the situation and maybe they will offer assistance to partially or completely repair the problems for free. If from an individual then you would be on your own for the repairs. Hope that helps. Bill