Need help with possible fuel issue

[Djohnson435]

I have a 2001 mustang GT I’ve owned the car for almost a year now car has been very reliable but here in the past couple of weeks it’s been acting up when I first start the car after it sitting over night or a few hours it runs great no issues but once it hits operating temperatures and I go to get on it or even go above 3500 rpm it starts to break up I broke down on the side of the highway for the first time from it breaking up so bad and it just acts like it’s starving for fuel I’ve changed the fuel pump/filter and put new injectors in but still has the same issue there is no codes being thrown at this time so I’m out of ideas anything will help thank you

 

[wmburns]

Just to confirm. You replaced the fuel injectors on a hunch?

Tell us about what you have done to rule int/out problems with:

• excessive EGR flow
• Have you MEASURED fuel pressure?
• Have you checked to be certain that the fuel pressure sensor (FRPS) intake vacuum reference line is connected and leak free?
• Have you checked to see if the PCM is getting good/reasonable values for IAT and ECT?

Do you have an ODB2 scanner capable of monitoring? Even better one with graphing capabilities? If so, it might short work of your problem.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/

With a good ODB2 scanner one can get easy answer to questions like:

• What does the PCM "think" the fuel pressure is?
• What is the MAF flow at the time?
• What is values for ECT and IAT?
• What are the O2 sensors doing at the time (lean or rich)? Are they switching rich and lean as they should?