Acceleration issue

Hi,

What you described can be a few things. First, is the check engine light staying on when the engine is running? If it is, scan the computer for diagnostic trouble codes.

Here is a quick video showing how it is done:

https://youtu.be/YV3TRZwer8k

I realize most people don't own a scanner, but most parts stores will do it at no charge or even lend / rent a scanner to you. If the light is on, this should be done.

Next, since there is an issue with power, the first thing I am suspecting is there is an issue with a weak fuel pump. Test fuel pressure to confirm there are no issues there.

Here is a link that shows in general how it's done:

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

Here are the directions specific to your vehicle for testing fuel pressure. The attached pictures correlate with the directions.

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2003 Nissan-Datsun Maxima V6-3.5L (VQ35)
Component Tests and General Diagnostics
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Pump Fuel Pressure Testing and Inspection Component Tests and General Diagnostics
COMPONENT TESTS AND GENERAL DIAGNOSTICS
Fuel Pressure Check
- When reconnecting fuel line, always use new clamps.
- Make sure that clamp screw does not contact adjacent parts.
- Use a torque driver to tighten clamps.
- Use Pressure Gauge to check fuel pressure.
- Do not perform fuel pressure check with system operating. Fuel pressure gauge may indicate false readings.

pic 1

1. Perform fuel pressure Release Procedure to zero.
2. Disconnect fuel tube joint between fuel damper and injector tube and set fuel pressure check adapter (J44321).

pic 2

3. Install pressure gauge to the fuel pressure check adapter as shown in the figure.
4. Start engine and check for fuel leakage.
5. Read the indication of fuel pressure gauge.
At idling: Approximately 350 kPa (3.57 kg/Sq cm, 51 psi)
6. If results are unsatisfactory, go to next step.
7. Check the following.
- Fuel hoses and fuel tubes for clogging
- Fuel filter for clogging
- Fuel pump
- Fuel pressure regulator for clogging
If OK, replace fuel pressure regulator.
If NG, repair or replace.

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Let me know if this helps. Also, let me know the results. Please keep in mind, I am basing this on the idea that the check engine light isn't on. If it is, there are other things which can cause it, so let me know.

Take care,
Joe