SuspiciousPizza Posted Friday at 05:52 PM Share Posted Friday at 05:52 PM For SPFI models, the fuel pressure discharge from the fuel pump is 36-50 psi. After the regulator is 20-24 psi @ 700rpm. The regulator drops the high pressure from the pump to a usable pressure for the injector. So there is a high pressure side and a low pressure side, separated by the fuel pressure regulator on the throttle body. Could be an issue with the fuel lines or filters. But most likely the fuel pump is tired and out of spec. Link to comment Share on other sites More sharing options...
cherrythesubaru Posted Friday at 08:00 PM Author Share Posted Friday at 08:00 PM Well wish I had done this check sooner! I'll see if I can find a pump and swap it out. Thanks! Link to comment Share on other sites More sharing options...
cherrythesubaru Posted Friday at 09:43 PM Author Share Posted Friday at 09:43 PM Searching around for a pump that will work. My local parts store carries this pump: https://www.rockauto.com/en/moreinfo.php?pk=1111648 Thoughts on this being a viable replacement? Link to comment Share on other sites More sharing options...
el_freddo Posted Saturday at 01:55 AM Share Posted Saturday at 01:55 AM I don’t know the SPFI well at all, are you sure the fuel pressure spec is 21psi? I thought it would be more inline with other EFIs like the EJs up at about 40psi. I’ve used the same external fuel pump for a NA MPFI EA82 and an EJ22. No issues. My thinking is that your fuel pressure is half of what it should be. This could be the fuel regulator or the fuel pump itself, or both. Pull the vac line for the fuel pressure regulator and make sure it doesn’t smell of fuel. If so, it’s dead. Cheers Bennie Link to comment Share on other sites More sharing options...
SuspiciousPizza Posted Saturday at 11:00 PM Share Posted Saturday at 11:00 PM Yeah that pump should work. Really so long as the pressure, voltage, and current draw are correct (the pump you showed looks to meet those specs) then these cars really don't care. I don't know if it'll last as long as an OEM or equivalent pump but it'll do the job. You may have to do some electrical work and figure out a mounting solution since this isn't an OEM equivalent pump but that's not a big deal and it's nothing too complicated. Sadly OEM/equivalent SPFI pumps are NLA but if you do ever want to keep a lookout for one, the part number is 42021GA242. Good luck, let us know how it goes. :] 1 Link to comment Share on other sites More sharing options...
cherrythesubaru Posted 5 hours ago Author Share Posted 5 hours ago Ok got that pump installed. Still only getting 19/20psi from it though... going to inspect my fuel lines and blow some air through them to see if there are any blockages. Link to comment Share on other sites More sharing options...
SuspiciousPizza Posted 4 hours ago Share Posted 4 hours ago Did you check that fuel filter down near the fuel pump? Too bad you had to go buy that pump but it'll give you more peace of mind in the future. Plus you can keep your old one in the car as a spare if you're ever in the situation you need it. If you do have to replace any rubber fuel hoses, Codan makes hoses that are the right diameter and are very good quality. Check out Volksbolts, they've got a good write up on fuel hoses. If you ever need some reading material. Link to comment Share on other sites More sharing options...
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