You should check the fuel pressure (the test port is near the firewall at the back of the engine).
For one reason or another, these vehicles absolutely need greater than 55 PSI of fuel pressure or they start hard and don't perform well.
Close LeAnne:
You need 3 things.
Compression
Good hot blue spark to all plugs.
Good gasoline and proper fuel pressure. 63-64 lbs.
If you have all 3 then move on to injector pulse to all injectors.
I think each injector is on a separate driver on that one.
Check for pulse to all of them.
It may be weak on fuel pressure . even a couple of lbs low on a cold start will cause a no start. Double check cold start cranking fuel pressure. If under 63-62 lbs you have problems. One test is to give it a squirt of carb cleaner not starting fluid. If it starts then you have a fuel pressure problem.
Run the full fuel pressure test and post back pressures. Here is the guide lines on testing.
Hard to start cold.
* Check cold start fuel pressure.
* Check engine running fuel pressure.
* Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
The 75-85 is only a check on the capable full pressure of fuel pump.
If you can not find the rubber return line check full pressure by plugging return line or just or the true full pressure can be taken direct at the end fuel filter.
The other thing also is to check your ground wire to the fuel pump, the ground wire a grounded separate to the frame from the fuel pump sending unit harness. Good luck and hope this helps.
