I have a 2006 Roush Stage 2 non-supercharged and sometimes after driving awhile when I go to take off the car acts like it has no power struggling to go over 3,000 RPM. I have seen the TSB on hesitation on acceleration, but my takes off fine just lacks power. I don't want to put a $300.00 fuel pump and doesn't fix the car. Any input would be apprieciated.

 

If you hadn't already tried running a diagnostics test that would probably point you in the right direction. But my 2000 gt was doing something similar, ran the test and code said it was the fuel pump driver module, turned out the fuel pump went out

 

Start with cleaning the TB, and not to say the obvious, but how's your air filter? Then I'd start looking at fuel delivery.

 

Whens the last time you had your fuel filter changed out and put some fuel cleaner in your tank? I use Chevron Techron fuel system cleaner about every 3,000 - 5,000 miles.

 

You can pick up a $20 fuel pressure gauge to check for fuel pressure issues. Don't just start throwing parts at it. You may also want to check the cats, they could have gotten jacked up. Had a '00 Camaro that the cats melted on. If you hit it with a screwdriver, they'll sound really solid if they're jacked up.

Are their any dash lights?

 

The fuel filter has been changed, the air filter has been cleaned and there are no codes stored. It's kind of hard to diagnose because it doesn't do it all the time and when it does do it it's for a short time. I could go and drive it right now and it won't act up. It has to have been driven a while and if the ambiant temp has to be high. That's why that TSB about the fuel pump makes sense that after extensive driving air bubbles form around the fuel pump causing a hesitation, but I want to be sure before I replace the pump.

 

Since you mentioned not having any codes stored, do you see the CEL come on but go off? If so, it could be a "soft" code thrown, I think I remember reading some posts recently where this was attributed to the Throttle Body wiring or Sensor... Here is a post that talks about a "soft-code"... . This probably won't help you identify the problem, but I only mentioned it because you tried to pull codes and nothing came up.

Don

 

No, the check engine light doesn't come on at all when the issue happens. I might just have to take a chance and put a fuel pump in it. I have a feeling that unless it gets worse it's going to be hard to diagnose.