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The engine does have a manual primer pump located on the fuel filter housing. Located next to the primer pump is the bleed screw.( be sure to remove it completely to prime fuel system . then after clear fuel comes out, reinstall screw and pump primer until hard)
Now if you had contaminated fuel ( water in fuel) This can cause the injectors not to pass the fuel through the injector tips. ( it just returns it to the tank)
I have also seen debris from a failed injection pump cause the injectors not to open , and also stick open. GM has a published bulletin regarding injector issues after replacing a failed injection pump. It is ( 08-06-04-029C )
Here is the description from the bulletin.
Some customers may comment on an illumination of the MIL/SES with one or more of the following symptoms:
Upon further investigation, the technician may find DTC P0087- Fuel Rail Pressure (FRP) Too Low stored in the ECM.
A ceramic high pressure valve ball fracture inside the fuel injection pump may lead to internal pump damage resulting in low fuel rail pressure. This condition may contaminate the common fuel rails and fuel injectors with debris. The fuel injection pump may operate, but with reduced output flow.
|• ||If the past repair order history shows the fuel injection pump was replaced, inspect the left fuel rail for debris and/or fuel contamination. It will be necessary to remove the fuel pressure relief valve to visually inspect inside the fuel rail. Refer to Fuel Pressure Relief Valve Replacement in SI.|
|- ||If particle debris is found in the left fuel rail, perform Steps 12-19.|
|- ||If no debris is found in the left fuel rail, install the fuel pressure relief valve and tighten. Perform the fuel injector return flow test by referring to Fuel Return System Diagnosis in SI.|
Tighten the fuel pressure relief valve to 100 N·m (74 lb ft).
|• ||If the vehicle will not start and/or there is evidence of a leak coming from the fuel injection pump, inspect for a missing or damaged cup plug on the fuel injection pump. If a damaged cup plug is found, perform Steps 11-19.|
|• ||If the fuel injection pump has not been previously replaced and there is no evidence that the cup plug is damaged, test the fuel injection pump for excessive fuel pressure fluctuations by following Steps 1- 10 below.|
Replace the fuel injection pump assembly. Refer to Fuel Injection Pump Replacement in SI.Replace the left and right fuel injector rails. Refer to Fuel Rail Assembly Replacement in SI.Replace all eight fuel injectors. Refer to Fuel Injector Replacement in SI.Reprogram injector flow rates. Refer to Fuel Injector Flow Rate Programming in SI.Flush all high pressure fuel lines of debris. Refer to Fuel System Cleaning in SI.Replace the fuel filter. Refer to Fuel Filter Replacement in SI.Prime the fuel system. Refer to System Priming in SI.Start the engine and inspect for fuel leaks. Refer to Fuel Leak Diagnosis in SI.Clear any codes and verify that the condition has been corrected.
This is not the complete bulletin, but as you can see if this has had a pump replaced there is a possibility for debris to enter the fuel system and contaminate the entire high pressure side of the fuel injection system .
This would entail a very expensive cleaning process, and replacement of fuel system components .( injectors, fuel rails, )
You can have the dealer inspect this per this bulletin to verify.