[chem_man]

Have you checked to see what your fuel pressure is and if your fuel pressure regulator is working properly and not leaking?

Have you ever changed the fuel filter?

 

[chem_man]

OK on hoping you could read the fuel pressure with the Tech II. I doubt that there is a fuel pressure senor in the fuel injection system.

Since no one else has asked, what DTCs are present (current, pending and historical)?

 

[chem_man]

OK. The reason why I asked is because if you were looking at a throttle body or an accelerator pedal problem, then a pending DTC would have likely shown up when you read the OBDII system. So, in the meantime, let's keep this simple and look for horses and not zebras.

Find out what the fuel pressure is, and I would be monitoring the short and long term fuel trims to see if something shows up (a sudden swing to the positive or negative) when you start to accelerate and feel the hesitation.

Now for another question. When you fill up with gas, do you keep goosing the gas nozzle after the pump initially shuts off in order to get a full tank (or a better dollar amount on the gas pump), or do you stop gassing up and return the nozzle to the pump? Please answer honestly.

 

[chem_man]

OK on the fuel trims. I am a little suspicious of the STFT in that it sees a larger change of 14% points. The LTFT looks OK.

Have you ever monitored both the STFT and LTFT values over a time period, say 10 to 30 minutes? What I would be looking for are swings to the negative by 10+ percentage points. It could indicate a fuel saturated charcoal canister. What happens in that case is the EVAP valves open allowing air to flow through the charcoal canister and become a fuel carrier and is introduced to the engine. When this happens, the STFT will go highly negative (indicating a rich condition) for a period of time indicating that the PCM is cutting back on the amount of fuel being introduced into the combustion chamber.

I had this happen to me on a 1999 Buick Century. When I filled up I would try and round it off to the nearest tenth of a dollar or sometimes just keep going until the tank was full. Well, after several years of doing that, it finally caught up with me and I wound up changing out the charcoal canister. The old canister was significantly heavier than it's replacement (an ACDelco OEM part). I imagine it would have taken years for all the fuel to be purged from the charcoal, if ever.

I'm not saying this is the cause of what you are experiencing, but it might be worth watching your fuel trims over an extended drive time of 20 - 30 minutes.

Also, when you find out what your fuel pressure is please let us know.

Good Luck!

 

[chem_man]

@TrFg24 - Welcome to the Forum!

For your benefit, please start a brand new thread of your very own so we can focus solely on you. Please remember to include Year, Make, Model, Sub-Model, Trim Level, Engine, Mileage, any and all Diagnostic Trouble Codes (DTCs) from the OBDII system, what warning lights on the instrument cluster are illuminated, a complete description of the problem you are experiencing, and any attempted repairs you have made. Also, please advise us on your level of automotive mechanical abilities - beginner, been working on vehicles for 5 years (oil changes, tune ups, brake work, etc.) or I'm 50+ years old and have been working on cars since I was in high school and the only thing I haven't done is to tear down, clean and rebuild an automatic transmission, ...

Thanks and waiting to hear back from you.