GREENSUBIE Posted May 2, 2006 Author Share Posted May 2, 2006 ok thanks ill check that out, but i think i might have tryed swopping it out but ill make sure im doin the right one It may be blue. My manual dosen't say what the color is. Quote Link to comment Share on other sites More sharing options...
Cougar Posted May 2, 2006 Share Posted May 2, 2006 After looking at the diagram again I saw there is a fuel pump relay also and suspect that may be the trouble since it is a common problem. My manual doesn't give the location of the relay but it may be in the console area with a number of other things. The wire colors shown to the relay are Blk, Blu/Red, Wht, and Blu. The Wht wire provides switched power to the Blu lead. The Blu lead then goes to the control box. The Blu/Red wire from the control box provides power to the pump. Power is provided through the Wht/Blk fusible link which goes to the relay so check the link and make sure you have power from there. Quote Link to comment Share on other sites More sharing options...
Sweet82 Posted May 2, 2006 Share Posted May 2, 2006 The fuel pump control unit may be black or blue depending on the year. My 82 was black with a Mitsubshi logo on it, 84's are typically light blue. You must match the FPCU to the carb. They are not necessarily interchangeable. The relay for the fuel pump may be under your passenger seat? Check under the carpet for a small cylinder. Trace the wiring back and you should find it. I'd also test the wires going off the FPCU and see if it is sending 12v back to the pump? Quote Link to comment Share on other sites More sharing options...
GREENSUBIE Posted May 2, 2006 Author Share Posted May 2, 2006 Ok, i found the fuel pump control unit, its blue with the mitsubshi logo, i found the relays under the passenger seat also, how would i match the FPCU to the carb? The fuel pump control unit may be black or blue depending on the year. My 82 was black with a Mitsubshi logo on it, 84's are typically light blue. You must match the FPCU to the carb. They are not necessarily interchangeable. The relay for the fuel pump may be under your passenger seat? Check under the carpet for a small cylinder. Trace the wiring back and you should find it. I'd also test the wires going off the FPCU and see if it is sending 12v back to the pump? Quote Link to comment Share on other sites More sharing options...
Sweet82 Posted May 2, 2006 Share Posted May 2, 2006 If your car was running normally before it quit, the FPCU you have is the proper one. If it is not putting out the power like it should then replace it with a FPCU with the same numbers on the box. Subaru used a couple different carbs and the boxes are specific to the carbs on the car. I'd check your system and find out where the 12v is stopping and the 3v is starting. Quote Link to comment Share on other sites More sharing options...
Cougar Posted May 2, 2006 Share Posted May 2, 2006 I would suspect the relay as the problem over the control unit. If you check the wires I told you about with your meter you will find the problem lies. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted May 2, 2006 Share Posted May 2, 2006 The two types of control units are for feedback(blue) vs. non-feedback(black). They are functionally equivelent, but the feedback carb version also controls choke power. GD Quote Link to comment Share on other sites More sharing options...
Sweet82 Posted May 3, 2006 Share Posted May 3, 2006 My Hatch, "Summer" is a 1982 Carter Weber and my box is black. My FPCU controls the choke as I have found out the hard way... I can "make" a blue one work but I have to jump a wire to the choke. The blue and the black boxes are wired differently. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted May 3, 2006 Share Posted May 3, 2006 DOH! Yeah - my bad - the feedback version does NOT control the choke - the ECU does. Sorry. GD Quote Link to comment Share on other sites More sharing options...
Cougar Posted May 3, 2006 Share Posted May 3, 2006 Before you get carried away with the FPCU, have you checked the voltage on wires that I mentioned earlier? I still suspect you have a relay problem and not a FPCU problem. Quote Link to comment Share on other sites More sharing options...
GREENSUBIE Posted May 3, 2006 Author Share Posted May 3, 2006 yea i checked the wire, at the FPCU (blue box) is where i traced the wires to and from there i aint getting any volts from the blue/red wire so i think there is a problem with the FPCU, because all the other wires have power that should have power, so i took apart one of my 2 FPCUs and tested it hooked up and found out that there is a switch on the circuit board and the switch isnt workin, so i went to radio shack and bought another switch ($2 wortha try) and if i screw it up i still got the other if its not the prob After looking at the diagram again I saw there is a fuel pump relay also and suspect that may be the trouble since it is a common problem. My manual doesn't give the location of the relay but it may be in the console area with a number of other things. The wire colors shown to the relay are Blk, Blu/Red, Wht, and Blu. The Wht wire provides switched power to the Blu lead. The Blu lead then goes to the control box. The Blu/Red wire from the control box provides power to the pump. Power is provided through the Wht/Blk fusible link which goes to the relay so check the link and make sure you have power from there. Quote Link to comment Share on other sites More sharing options...
Cougar Posted May 3, 2006 Share Posted May 3, 2006 It has a switch you say. I assume you are talking about a relay and it may be bad. If you had 12 volts on the Blu wire then the problem is within the control unit or the ECU which controls the FPCU I think. One other thing to check is the spark. If the system is not generating a spark then it may shut the pump down for safety reasons. Quote Link to comment Share on other sites More sharing options...
GREENSUBIE Posted May 3, 2006 Author Share Posted May 3, 2006 no the blue and red wire has nothin, no volts, but there is a little switch in side the bluse box, i opened it up and tested around and found a relay or what ever it is i think its a switch to control the voltage for the fuel pump, but anyhow i went to radio shack and bought another and am replacing it, It has a switch you say. I assume you are talking about a relay and it may be bad. If you had 12 volts on the Blu wire then the problem is within the control unit or the ECU which controls the FPCU I think. One other thing to check is the spark. If the system is not generating a spark then it may shut the pump down for safety reasons. Quote Link to comment Share on other sites More sharing options...
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