When you know it's gonna give you a hard start, try turning the key on and off 3 times before actually starting it. If it fires right up, then you have fuel pressure bleeding off. I know you said fuel pressure checked fine, but once the car is running it will be fine. There is an anti-drain back valve in the fuel pump that is supposed to prevent pressure from rapidly dropping, if it's gone bad, you will get symptoms like you describe. The only way to fix it is to replace the pump. I drove a car with this issue for over a year before I got around to replacing the fuel pump. One way to confirm is hook a gauge up, turn the key on
(but don't start) and see if it holds at 40PSI or better for at least 10 minutes. If it drops off right away, then it's likely the drain back valve in the pump.
For the coolant sensor codes, check the plug and wiring (at the water pump) and make sure everything is in good shape. It's often that stuff and not the actual sensor causing the issue.
Also, for future reference, for engine/drivetrain related problems, it's best to use the other sections. The engine maintenance section gets a lot more traffic than the roadmaster section and you'll get more responses. Only post in this section if it is something roadmaster specific.
Last edited by Goldmaster; 08-21-2013 at 01:48 PM.