Hard to start

Good afternoon.

Can you tell me the code and what parts you replaced?

As far as the hard start, there is a spider assembly that contains the injectors and the regulator. The regulator is common for leaking raw fuel into the intake causing a flooding condition.

I would start with a fuel pressure test to verify fuel pressure especially when it sits overnight.

It sounds like you will possibly need the spider assembly.

Roy

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

1. Disconnect the negative battery cable.
2. Relieve the fuel system pressure. Refer to Fuel Pressure Relief Procedure.
3. Remove the upper intake manifold assembly.

NOTE: Do not use any solvent that contains Methyl Ethyl Ketone (MEK). This solvent may damage fuel system components.

4. Before removal, clean the fuel meter body assembly with a spray type engine cleaner, GM X-30A or the equivalent, if necessary. Follow the package instructions. Do not soak fuel meter body assemblies in liquid cleaning solvent.

NOTE: Cover the injector sockets in order to prevent dirt and other contaminants from entering the open fuel passages.

IMPORTANT: When disconnecting the poppet nozzles, remember the sequence in order to ensure correct poppet nozzle placement to each cylinder.

5. Squeeze the poppet nozzle locking tabs together while lifting the nozzle out of the casting socket.

imageOpen In New TabZoom/Print

6. Remove the fuel meter body from the bracket by releasing the lock tabs on the bracket.

Is the 446 still active?

Roy

Okay, clearing a code does nothing. It needs to be diagnosed and repaired. Besides, it has no effect on your current issue.

Again, what parts have been changed?

Roy

CIRCUIT DESCRIPTION
The Power-train Control Module (PCM) monitors the performance of the Evaporative Emission (EVAP) system by applying a predetermined level of vacuum to the EVAP system then monitors the vacuum decay rate. The PCM sets this Diagnostic Trouble Code (DTC) if the vacuum decay rate is more than a predetermined value.

CONDITIONS FOR RUNNING THE DTC
DTCs P0107, P0108, P0110, P0112, P0113, P0115, P0117, P0118, P0121, P0121, P0122, P0123, P0125, P0440, P0442, P0443, P0449, P0452, P0453, P1106, P1107, P1111, P1112, P1114, P1115, P1121, or P1122 are not set.
The ignition voltage is between 10-18 volts.
The Barometric Pressure (BARO) is more than 75 kPa.
The fuel level is between 15-85 percent of full capacity.
The Engine Coolant Temperature (ECT) is between 4-30°C (39-86°F).
The Intake Air Temperature (IAT) is between 4-30°C (39-86°F).
The start up ECT and the IAT are within 9°C (16°F) of each other.

CONDITIONS FOR SETTING THE DTC

IMPORTANT: This DTC does not report a first failed test. A first fail of this DTC will have a scan tool status as Not Run.
The EVAP vacuum decay rate is more than a predetermined value.
The conditions are present for more than 2 seconds.

OR

The vacuum present in the EVAP system is more than a predetermined value.
The conditions are present for more than 4 seconds.

ACTION TAKEN WHEN THE DTC SETS
The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS

IMPORTANT:
Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.
An accurate indication of fuel level is required for the PCM to properly pass or fail this DTC. Always diagnose the fuel level sensor DTCs before using the diagnostic table for this DTC. Always inspect for fuel level sensor DTCs that are stored as History.
The Service Bay Test may have to be performed in cold ambient air temperatures when the vehicle is running a winter grade fuel. The scan tool displays a message when the Service Bay Test does not run.
Inspect for a charcoal release from the vapor canister. Refer to Evaporative Emission (EVAP) System Cleaning procedure. See: Evaporative Emissions System > Procedures > Evaporative Emission (EVAP) System Cleaning

CONDITIONS FOR RUNNING THE SERVICE BAY TEST
The battery voltage is between 10.5-17.5 volts.
The fuel level is between 15-85 percent of the full capacity.
The engine temperature is between 3.5-35°C (38-95°F).

Perform a physical inspection of the EVAP system. Inspect for the following conditions:
A loose, missing, defective, or incorrect fuel tank cap
Incorrectly routed or defective EVAP system vacuum and vapor lines
A malfunctioning or damaged vapor canister
Charcoal release from the vapor canister-Refer to Evaporative Emission (EVAP) System Cleaning. See: Evaporative Emissions System > Procedures > Evaporative Emission (EVAP) System Cleaning

imageOpen In New TabZoom/Print

The vacuum and pressure in the EVAP system is measured in inches of water (H2O). Most gauges measure vacuum in inches of mercury (Hg) and pressure in pounds per square inch (psi). The table shows how the values compare.

Okay, so the purge valve was the only thing replaced for the evap system issue.

I would check the vent valve for the fuel tank. It may be stuck open causing this code.

You need a scan tool to work the valve and see if it opens and closes on command.

Roy

. Turn OFF the ignition.
2. Raise the vehicle.
3. Remove the spare tire (underbody mounted spare tire only).
4. Disconnect the EVAP canister vent valve harness connector.
5. Disconnect the vent hose (1) from the EVAP canister vent valve (2).
6. Release the tang on the vent bracket (4).
7. Remove the vent valve (2) from the bracket (4).

Okay, and it opened as well and you could blow through it?

Was there voltage to the solenoid with the key on?

Roy

Thanks for your service.

Okay, the PCM is what grounds or opens and closes those solenoids.

That is why you need a scan tool to see if it is doing its job. It may very well be a failing PCM.

Roy

You are welcome.

Roy