funky monk Posted June 10, 2013 Share Posted June 10, 2013 Since picking up my car a month ago, I'd been experiencing a hesitation between 2-3k, slow start and rough idle on warm start. After finally getting to Cobb last week (not before wasting $100 at Renick first) they found that the fuel pressure was too high under load and that it dropped to 0 when the car shut off. I had the fuel pump changed to a DW unit and when they pulled the stock one out, this is what they found: http://legacygt.com/forums/picture.php?albumid=1655&pictureid=8502 It's a bit difficult to see and they're very fine particles but some were caught in the pump filter. No one there had seen this before and neither had any of the 3 guys at my regular shop. We're unsure what it's from but it has to be something in the tank. They're also unsure if any got farther along through the fuel system. After changing the pump, the hesitation seems to be gone but the pressure is still high (69 psi) under accel with 33 at idle. From what I understand, the normal range is mid 30's, correct? Starting is better but still slow at times. Has anyone had issues like this before? For reference, car is currently stock but previously had DP, manual boost controller and stg 2 protune. No modifications to fuel system and no reason the tank should have metal in it. Link to comment Share on other sites More sharing options...
I Donated Too sigmafour Posted June 10, 2013 I Donated Too Share Posted June 10, 2013 are they rust particles/ferrous material, did you try putting a magnet near them to identify the type of metal? How do you know so much about the previous mods and are you absolutely sure the fuel system was never modded and returned to stock? Link to comment Share on other sites More sharing options...
funky monk Posted June 10, 2013 Author Share Posted June 10, 2013 Didn't use a magnet. PO kept good records. He also included the parts with the car. Nothing in the records indicates work was done on the fuel system and he put everything in there including oil changes. Link to comment Share on other sites More sharing options...
13fido13 Posted June 10, 2013 Share Posted June 10, 2013 Could simply be metal shavings from fuel system manufacture. I'm sure some pieces slip into the tank when they are drilling. Link to comment Share on other sites More sharing options...
Rizz01 Posted June 21, 2013 Share Posted June 21, 2013 First, fuel pressure coming out of the tank should be 50-60 psi. The pressure after the regulator should be around 40 psi at idle, warmed up with no check engine light. The lower limit is 38 psi. Goodness knows what we could potentially pick up at the gas pumps and its a real roll of the dice. I had a very similar issue an changed the sending unit. Unless you already know, the sender not only contains a rheostat for fuel level indication and a pump, there's also a fuel temp sensor, a pressure sensor, and a filter. According to knowledgeable Subaru techs, the unit should be changed shortly after 100k. It hurts since the unit costs $312 from Subaru. The aftermarket versions are around the same cost, so stick with the OEM. Anyway, dropped the new unit in and solved my issues. Hope this helps! Good luck!!!! Link to comment Share on other sites More sharing options...
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