2002 996TT Low Fuel Pressure troubleshooting help needed
2002 996TT Low Fuel Pressure troubleshooting help needed
Recently when driving if I noticed if I accelerated quickly the car would sputter which to me typically is a fuel starvation problem. Tthe problem came on rather quickly the car drove fine when I initially took it out and on the way home during a 20 minute drive the problem surfaced. I checked the fuel pressure at the connector by the fuel filter and found the pressure was running about 35 PSI with the car idling vs the needed 55-60 PSI. My thought... the car sat for a long time 3+ years at one point and it probably had questionable fuel which probably killed the pump. I replaced the pump with a Walbro (now known as TI Automotive )F90000262 400LPH, adapter, and pump pick up sock from Radium Engineering to mount it in the stock pick up tank in the fuel tank. The small rubber hoses (a common failure point) have been replaced. The fuel filter has less than 500 mi on it. I also double checked all of the electrical connectors to the pump when it was out and everything was in good condition. The car is stock with no performance modifications.
When I started the car after the new pump was installed and took the car for a test drive it was performing in a similar manner... sputtering and bucking under acceleration. The car starts fine, warms up, idles fine, and there no codes have been thrown. There are no leaks. I checked the fuel pressure again and got a steady 35 PSI. The 35PSI remains when the car is shut off with no leak down or loss of pressure after several hours. I am assuming if there is no pressure leak down after the car is shut off the check valve is also OK which leaves only the fuel pressure regulator as a possible problem or the fuel pump is bad right out of the box?
This is my first post. I checked the available information extensively and ruled out some of the common problems already. Any thoughts on my approach to troubleshooting? I wanted to get some feedback and advice before I decided to pull and replace the fuel pressure regulator or try another fuel pump. Thoughts and feedback would be appreciated!
When I started the car after the new pump was installed and took the car for a test drive it was performing in a similar manner... sputtering and bucking under acceleration. The car starts fine, warms up, idles fine, and there no codes have been thrown. There are no leaks. I checked the fuel pressure again and got a steady 35 PSI. The 35PSI remains when the car is shut off with no leak down or loss of pressure after several hours. I am assuming if there is no pressure leak down after the car is shut off the check valve is also OK which leaves only the fuel pressure regulator as a possible problem or the fuel pump is bad right out of the box?
This is my first post. I checked the available information extensively and ruled out some of the common problems already. Any thoughts on my approach to troubleshooting? I wanted to get some feedback and advice before I decided to pull and replace the fuel pressure regulator or try another fuel pump. Thoughts and feedback would be appreciated!
Definitely replace fuel filter even if fairly new…when that car sat all crud went in to filter. Also, Peter I need to award you the fewest posts per year on 6 speed. One post in 10 years. Congratulations. Unfortunately, someone ran off with your gift.
Last edited by GT3 Chuck; Nov 25, 2025 at 05:06 PM.
Did you figure this out?
You can't just guess that the problem is low fuel pressure and a car sitting with old fuel will not make the pump go bad.
You need Durametric to check codes and log while you drive to see what the problem might be.
You can't just guess that the problem is low fuel pressure and a car sitting with old fuel will not make the pump go bad.
You need Durametric to check codes and log while you drive to see what the problem might be.
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