Thanks for the information.
If it is stiff after shutdown, then I would think you do not have a fuel pressure problem. I would suspect something else.
Lets try and pull the fault codes from the engine ECM. I have seen the ECM be the problem when the injector driver module inside of the ECM fails. When this happens, you will have fault codes in the ECM for all 6 injectors. If you have never done this before, here is how to pull the codes. All codes are 2 digits.
Use the following procedure to retrieve the flash codes if the engine is equipped with a diagnostic lamp:
- 1. Turn the ignition keyswitch to the On position/ Engine OFF.
- 2. Turn the cruise control ON/OFF switch to the OFF position.
- 3. Move the SET/RESUME switch to either position. Hold that position until the yellow lamp begins to flash.
The yellow lamp will flash in order to indicate a two digit flash code and the SET/RESUME switch may be released. The sequence of flashes represents the system diagnostic message. Count the first sequence of flashes in order to determine the first digit of the flash code. After a two second pause, the second sequence of flashes will identify the second digit of the flash code.
Any additional flash codes will follow after a pause. These codes will be displayed in the same manner. Flash Code 55 indicates that No Detected Faults have occurred since the ignition keyswitch has been turned to the ON position.
Let me know what codes you get (if any) and I can tell you what they mean.