adamv3 Posted January 3, 2010 Share Posted January 3, 2010 Alright guys my subaru has got me totally stumped. It's an 89 GL SPFI 4WD. Two days ago I drove it to my dad's garage to change the passenger side axle. Car drove there fine and hasn't given me any real running issues since I have owned it. After tackling the axle I went to start it and noticed the fuel pump wasn't engaging (I can usually hear it pulsing when ignition is on). After some research on this site I did some testing and here are the results -replaced the relay, still nothing -sent direct power to the pump and fuel is definitely getting to the engine(unplugged a fuel line at the filter) -engine will not run even with direct power to the pump -check all the applicable fuses under the dash -disconnected/reconnected the negative battery cable idk about subies but this is how I have always reset ECU's After all this testing I can't get the fuel pump to turn on under the power of the car and even with direct power it will not start. I'm wondering if there is a main fuse or an ECU fuse located somewhere else that I am not aware of or if I knocked a critical ground wire loose in the axle changing process. To change the axle I did beat on the control arm quite aggressively but nothing more than I did to change the ball joints. Any help will be greatly appreciated as this is my daily driver right now. Thanks, Adam. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 3, 2010 Share Posted January 3, 2010 The fuel pump does not run unless the ECU detects a tach signal, or you are cranking. I doubt that the fuel pump is even related to your problem. If you usually hear it pulsing then I would guess that someone has left the test connectors connected - green two-pin connector under the dash or behind the strut tower.... Check the fuses first. Might have a blown fuse that powers the ECU. And check the fusible links - test across them for voltage. Check for spark. Sounds to me like something in the ignition is loose or damaged. GD Link to comment Share on other sites More sharing options...
adamv3 Posted January 3, 2010 Author Share Posted January 3, 2010 Ok I want to test these things tomorrow but I'm not very familiar with some of these electronics. Where are the fusible links located? And as far as these test connectors are concerned, there is a box in front of my strut tower with 4 green or black U-shaped wires are these what you are referring to? They all appear to form a U and are connected at both ends. Is the ecu fuse located in the main fuse box under the dash? I apologize for my ignorance on this matter and appreciate the help. Link to comment Share on other sites More sharing options...
john in KY Posted January 3, 2010 Share Posted January 3, 2010 That box next to the battery contains the 4 fusible links. Test connector should be close to the brake MC. If I am reading what you posted correctly, you have fuel flow. Have you checked for spark? Fuse box should have one marked IGN. Good idea to check that one. Remove the distributor cap and verify the rotor turns while cranking the engine. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 3, 2010 Share Posted January 3, 2010 Disconnect both the green and black wires behind the strut. Those are for testing and should always be disconnected. That's why your fuel pump cycled with the key on. Now that it doesn't cycle anymore I would say you have a definite electrical problem. Probably a power supply to the ECU is disconnected somewhere. GD Link to comment Share on other sites More sharing options...
MilesFox Posted January 3, 2010 Share Posted January 3, 2010 take off the distributor cap and observe the rotor is spinning when the engine cranks. if the rotor is not turning, see if the set screw fell out. easy fix if so. otherwise if the distributor is not turning, suspect a broken timing belt. do this first to rule that out before going into electrical troubleshooting. the test clips are for retrieving trouble codes and setting initial timing check fuse #5 horn/hazard/clock. this is hot all the time and is live with the ecu Link to comment Share on other sites More sharing options...
adamv3 Posted January 3, 2010 Author Share Posted January 3, 2010 The rotor is turning in the distributor, I forgot to add that we checked that. In order to be totally clear, the 4 U-shaped wires in front of the strut tower are the fusible links, correct? And the test connectors are sets of wires with plugs that are closer to the firewall on the driver's side? I will upload pictures when I arrive there today. As far as power to the ECU goes, where should I be looking for a possible failure? Are there places that are common for breaking connection or a main ground that could have come loose? Link to comment Share on other sites More sharing options...
GeneralDisorder Posted January 3, 2010 Share Posted January 3, 2010 Yes - the wires behind the strut tower closer to the firewall are the test connectors and the U shaped one's are the fusible links. Check for +12v on both sides of the links. They have constant power supply even with the ignition off. As for where you will find the problem - that's anyone's guess. Your problem is not at all common or typical. My guess is the fusible links are loose or corroded but that's only a guess. One of them is a major power supply to the ECU. But there are half a dozen different power supplies to the ECU so it could be something else. GD Link to comment Share on other sites More sharing options...
Log1call Posted January 3, 2010 Share Posted January 3, 2010 Given that you drove the car into the workshop, I'd have to suppose that whatever is wrong has been caused by the work you did to the car. I'd stop disturbing stuff for the time being and just look really carefully all around where you were working, especially under the bonnet. You must have bumped something, perhaps a wire, perhaps a vacumm pipe. If you keep fiddling you might just obscure the problem worse than ever in my opinion. Link to comment Share on other sites More sharing options...
adamv3 Posted January 4, 2010 Author Share Posted January 4, 2010 So after many hours of useless troubleshooting the problem turned out to be the clock fuse. I never would have thought to check that fuse and still don't fully understand why it is constantly hot to the ecu. If it wasn't for you Subaru gurus this could have taken me days to figure out, so thank you greatly for all your help. Now the issue seems to be the fuse has blown for a second time. After replacing the fuse the car started multiple times just fine. I drove it home (about 30 miles) with no issues and parked it for the night. I went to start it this morning and it gave me the same issue so I changed the fuse and it started right up. Is there anything in particular that causes this fuse to blow? Link to comment Share on other sites More sharing options...
Loyale 2.7 Turbo Posted January 4, 2010 Share Posted January 4, 2010 Glad to Read that you Found the Problem's Cause, but this... ...the problem turned out to be the clock fuse. I ... don't fully understand why it is constantly hot to the ecu. ... ...is Not a Normal Behaviour as far as I Know on those Subies, Could I Ask if you or the Previous Owner did installed something like an Aftermarket Radio (The ones that Needs a Constant ON Power wire to Keep the Settings in Memory) or Halogens, or Alarm, or anything like That? ... Because maybe there is a Misplaced wire at the Fuse Box. So I Kindly Suggest you to take out the Fuse Box and check each Wire for some unwanted power Detour, also Maybe there could been a Loose Wire that could have "Moved" when you Worked the Axles... I Hope this could Help. Kind Regards. Link to comment Share on other sites More sharing options...
adamv3 Posted January 4, 2010 Author Share Posted January 4, 2010 I did install an aftermarket stereo myself but I didn't modify any of the wiring, I just purchased a harness to fit the car. I have only owned the car for a few months and it has never given me any mechanical issues until now. The car appears to be totally unmodified to the best of my Subaru knowledge which is obviously not very extensive. Link to comment Share on other sites More sharing options...
MilesFox Posted January 4, 2010 Share Posted January 4, 2010 i was going to ask if you had an aftermarket radio. there is a green wire behind the stereo that is hot all the time, and if you short that out, there goes your #5 fuse. double chack your radio harness and make sure this wire is not grounding out. that may very well be your issue. i had the same issue and tore half my dash out, backfed power to this green wire, to later discover i had blown the same fuse! Link to comment Share on other sites More sharing options...
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