Engine hesitates when accelerating?

Hello,

This could be a problem with your fuel filter. I have included down below that will take to a guide that will help you troubleshoot your vehicles problem. Go through it and get back to us with what you find out.

https://www.2carpros.com/articles/engine-hesitates

Thanks,
Alex
2CarPros

What was the code? You need to post that info for us. The code won't say vacum leak. And with the symptoms you are describing, it could be anything. We are only as good as thr info we are given.I want to help you but I need more to go on.

You will not be able to override the check light, the engine and engine management system is designed to run with the cat converter, the system must run with converters in place.

CEL/SES On

What you need to do here is have the computer scanned for OBD2 codes, there's a problem within the engine management system that caused the light to turn On, this is your starting point of diagnosis

Have you checked fuel pump pressure and drop off rate?

Hi and thanks for using 2CarPros.com. Has the check engine light come on? If so, have you scanned to determine if there are trouble codes stored?

Here is a video related to using a scanner:
https://youtu.be/YV3TRZwer8k

If no trouble codes exist, I would then recommend checking the coolant temperature sensor. Here is a description from alldata of what it does. If the sensor isn't working properly and provides false information to the computer, the air fuel mixture will be wrong and can cause what you are experiencing.

The Engine Coolant Temperature (ECT) sensor is a thermistor, a resistor which changes value based on temperature, mounted in the left cylinder head. Low coolant temperature produces a high resistance, 100,000 ohms at -38°C (-39°F) , while high temperature causes low resistance 70 ohms at 130°C (266°F) .

The Powertrain Control Module (PCM) supplies a 5.0 volt signal to the ECT sensor through a resistor in the PCM and measures the voltage. The voltage is high when the engine is cold. The voltage is low when the engine is hot. The PCM calculates the engine coolant temperature by measuring the voltage. The engine coolant temperature affects most systems the PCM controls.

The scan tool displays engine coolant temperature in degrees. When the engine starts, the engine coolant temperature should rise steadily to about 90°C (194°F) then stabilize when the thermostat opens.

The engine coolant temperature and intake air temperature should be close to each other if the engine ha8 not been run for several hours, overnight. The following DTCs set when the PCM detects a malfunction in the ECT sensor circuit:
DTC P0117 ECT Sensor Circuit Low Voltage
DTC P0118 ECT Sensor Circuit High Voltage
DTC P0125 Excessive Time to Closed Loop
DTC P1114 ECT Sensor CKT Intermittent Low Voltage
DTC P1115 ECT Sensor CKT Intermittent High Voltage

If you find the sensor to be faulty, here are directions for removal and replacement. Additionally, there are pictures to follow for part and location identification.

REMOVAL PROCEDURE
Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
Drain the engine coolant. Refer to Draining and fitting Cooling System in Engine Cooling.
Lower the vehicle.
Disconnect the electrical connector from the Engine Coolant Temperature (ECT) sensor.
NOTE: Refer to Handling Coolant Sensor Notice in Cautions and Notices.
Remove the ECT sensor.
INSTALLATION PROCEDURE
NOTE: Refer to Handling Coolant Sensor Notice in Cautions and Notices.
Coat the ECT sensor threads with sealer GM P/N 12346004 or the equivalent.
NOTE: Refer to fastener Notice in Cautions and Notices.
Install the ECT sensor.
Tighten
Tighten the ECT sensor to 20 N.m (15 lb ft) .
Connect the ECT sensor electrical connector.
Refill the engine coolant. Refer to Draining and fitting Cooling System in Engine Cooling.
Start the engine and check for leaks.
Reinspect the engine coolant level. Refer to Draining and Filling Cooling System in Engine Cooling.

I hope this helps. Let me know if you have other questions or need additional help.

Take care,
Joe

The first thing I would do is monitor the fuel pressure through this entire period to document what the pressure does. This engine is extremely pressure sensitive and must have over 55PSI at all times.

Do you hear the fuel pump for a few secs when you turn key to run? If so do a fuel pressure test if not check ECM B fuse and fuel pump relay then report back

Sounds like a bad fuel pump. You need to hook up a pressure gauge to the fuel pressure service port and measure the pump's output pressure. It should be around 55 to 60 PSI.

Pump is in the tank. If the pressure is low, replace the pump and the fuel filter.

Use a gage and check for proper fuel pressure fuel pressure. Can you check for applicable trouble codes? Some of the national brand autostores will check codes for free.