ferp420 Posted August 24, 2016 Share Posted August 24, 2016 Is there a good ground from the bat to the body to the motor to bat to motor to body if you loose one of those grounds everything goes haywire maybe the previous owner took one off or broke it and didn't hook it back up when he changed the battery its just so easy to over look Quote Link to comment Share on other sites More sharing options...
Shortaay Posted August 24, 2016 Author Share Posted August 24, 2016 (edited) The fuel pump relay coil and one contact terminal gets +12V via a Black / White wire, from a 15A fuse that is switched by the ignition switch. The other end of the coil is run via Blue / Black to the ECU. The contact terminal that goes to the pump is a blue / white wire. The Black/White wire should have +12 with the key in run position. The Blue Black should be close to GND, but won't stay there after about 3 seconds of non running engine. The Blue White should be opposite of the Blue Black. What matches / doesn't match with what you are seeing? I will have to check this again... I have 4 wires in my connector I do have 12v with key on on the thicker gauge black and white wire. If I jump it to the other thicker gauge wire I get 12v at the pump. I will have to check the close to ground tonight when I get home I think thats where I was getting myself confused. So the ecu actually sends the ground? Is there a good ground from the bat to the body to the motor to bat to motor to body if you loose one of those grounds everything goes haywire maybe the previous owner took one off or broke it and didn't hook it back up when he changed the battery its just so easy to over look Ground off battery goes in a big bundle back towards the starter. There is a ground from the body to the bracket on the the cylinder head and a ground from the coil bracket to that same bracket on the head. Should I add a ground from neg post directly to body? Edited August 24, 2016 by Shortaay Quote Link to comment Share on other sites More sharing options...
DaveT Posted August 24, 2016 Share Posted August 24, 2016 There should be a 10 or 8 AWG wire from battery - directly to the body. Use an existing hole in the sheet metal within the reach of about 10" of wire. Scrape the paint off, and apply some wheel bearing grease to keep the joint from corroding. Quote Link to comment Share on other sites More sharing options...
DaveT Posted August 24, 2016 Share Posted August 24, 2016 Yes, the ecu pulls that wire to gnd to activate the relay. Quote Link to comment Share on other sites More sharing options...
Shortaay Posted August 24, 2016 Author Share Posted August 24, 2016 Ok I have some extra 8 ga in my toolbox and some extra ends, I will add a ground or 2 tonight, and I will check the ground on my relay Quote Link to comment Share on other sites More sharing options...
Shortaay Posted August 29, 2016 Author Share Posted August 29, 2016 Finally got a chance to do some testing I have no wires that are going to ground when I turn the key on at the relay plug does that mean I have a bad ECU or is there a chance of something else being the problem Quote Link to comment Share on other sites More sharing options...
DaveT Posted August 29, 2016 Share Posted August 29, 2016 Sounds like it, or the wire Going to it. Before replaceing the ecu, I would unhook the signal wire from the relay, and try grounding that relay coil terminal to verify that the relay turns on the pump. Removing the 3 connector from the ecu should isolate it so it is safe to test the relay. Quote Link to comment Share on other sites More sharing options...
Shortaay Posted August 29, 2016 Author Share Posted August 29, 2016 (edited) Ok. I will try that when I get home also I still don't know why I have 4 wires on my plug. I have 2 thicker gauge wires black with a white stripe then I have the blue and white and the blue and black as discussed above. Jumping the right black and white to the blue and white does give 12v back to the pump Anyone had one of these ecus apart? Im curious what controls the initital pump run before I uses crank signal. I have an electronics genius at my work. I might pull my ecu back out and find a pinout and see if we can trace it down Edited August 29, 2016 by Shortaay Quote Link to comment Share on other sites More sharing options...
Shortaay Posted August 29, 2016 Author Share Posted August 29, 2016 (edited) I might attempt this first... http://www.ultimatesubaru.org/forum/topic/74173-how-to-repair-a-damaged-ecu-for-ea82-if-the-fuel-pump-doesnt-run/ Although it says MPFI Edited August 29, 2016 by Shortaay Quote Link to comment Share on other sites More sharing options...
DaveT Posted August 29, 2016 Share Posted August 29, 2016 I have opened one or 2. They are computer controlled. At one time I was going to reverse engineer the things, but I have not yet needed to. Quote Link to comment Share on other sites More sharing options...
robm Posted August 30, 2016 Share Posted August 30, 2016 If you dig deep, you will find a thread on this website about the internals of the ECU, and specifically the transistor that is triggered to turn on the pump. The timing thing that fires it for startup, then keeps the pump running when the engine starts, is bound to be in the software, If the transistor is bad, it is possible to replace it, but another ECU is probably a lot easier way to go. If a new ECU fixes the problem, then turn your electronic guru loose on the old ECU. If he fixes it, great, if not, no harm done. Quote Link to comment Share on other sites More sharing options...
Shortaay Posted August 30, 2016 Author Share Posted August 30, 2016 Yeah. between wisdom tooth issues and my birthday I havent got to verify 100% that the ecu is the issue. I found the post linked above for the MPFI but havent found anything for SPFI yet. I have a whole box of parts on the way. Been trying to source a cheap ECU locally but havent found much as usual. Quote Link to comment Share on other sites More sharing options...
robm Posted August 30, 2016 Share Posted August 30, 2016 I would still try swapping in a different relay. There are 3 of them right beside the FP relay. Quote Link to comment Share on other sites More sharing options...
Shortaay Posted August 30, 2016 Author Share Posted August 30, 2016 Ive done that. There is no switching ground going to the relay Quote Link to comment Share on other sites More sharing options...
robm Posted August 31, 2016 Share Posted August 31, 2016 Good start. Run a wire direct from the battery to the red wire on the pump to make it run, and then try to start the car. (I ran mine for months like this, off and on depending on how co-operative the relay was feeling that day.) The ECM may have more than one problem, or the problem it has may exhibit more symptoms besides the FP not working. Quote Link to comment Share on other sites More sharing options...
Shortaay Posted August 31, 2016 Author Share Posted August 31, 2016 That's what I'm thinking. It wouldn't start with starting fluid either. So I have a possible spark issue as well. I have a good working fuel pump, relay, coil, dist cap, rotor and wires on the way for diagnosing. Next question what do I need to find when I'm looking for an ECU do I need to stick with 90-93 Loyale with the exact same setup as mine Quote Link to comment Share on other sites More sharing options...
DaveT Posted August 31, 2016 Share Posted August 31, 2016 I have Seen mention of a pin that tells the ecu if it is running with a standard or auto transmission. So that should not matter. I've swapped spfi engines between 87 gl through 93 loyale, no problem, never had to change out the ecu. Possible difference may exist between CA and 49 state, but I do not know. Quote Link to comment Share on other sites More sharing options...
Shortaay Posted August 31, 2016 Author Share Posted August 31, 2016 Well I found one locally from an 88 GL with an automatic if it'll work I will grab it Quote Link to comment Share on other sites More sharing options...
Shortaay Posted September 14, 2016 Author Share Posted September 14, 2016 I'm getting annoyed now. Parts replaced so far. Distributor cap, rotor, wires, coil with bracket, fuel pump, fuel pump relay and ecu. Still no ground at the relay... Quote Link to comment Share on other sites More sharing options...
Shortaay Posted September 15, 2016 Author Share Posted September 15, 2016 Obviously, alot of the parts replaced werent totally related to the problems but needed to be done just to to mileage and condition. Just trying to figure out what my next step is. If I have green connectors plugged under the hood and I still have no ground turning on and off at the relay. Do I have a wiring issue between ecu and the relay? Quote Link to comment Share on other sites More sharing options...
robm Posted September 15, 2016 Share Posted September 15, 2016 Can you get the car to run at all? It is rude, crude and ugly, but just run a wire from the battery to the pump, and see if it will start. I drove mine like this for months. Put an inline fuse on the wire, it is even more or less safe. A running car is a good start. Can you determine which pin in the ECU harness is for the fuel pump? Is there continuity between there and the relay? Can you see ground on that pin when the green connectors are together, so it should be pulsing the fuel pump? Does the pump run if you ground the relay (bypass the ECU)? Quote Link to comment Share on other sites More sharing options...
Shortaay Posted September 15, 2016 Author Share Posted September 15, 2016 Can you get the car to run at all? It is rude, crude and ugly, but just run a wire from the battery to the pump, and see if it will start. I drove mine like this for months. Put an inline fuse on the wire, it is even more or less safe. A running car is a good start. Can you determine which pin in the ECU harness is for the fuel pump? Is there continuity between there and the relay? Can you see ground on that pin when the green connectors are together, so it should be pulsing the fuel pump? Does the pump run if you ground the relay (bypass the ECU)? I havent had the car running whatsoever.The pump is back out the car right now so I can replace a cracked hose. I will have it installed this afternoon. I have 12v at the pump itself if I jump the relay. I havent tried grounding the relay yet. Its soo damn tight up in those bundles of wire, tracing the wire has been a nightmare. I will do a continuity test this afternoon. I get no ground on that pin even with the green connectors together Quote Link to comment Share on other sites More sharing options...
Shortaay Posted September 15, 2016 Author Share Posted September 15, 2016 (edited) I'm to the point now where I almost just want to cry according to the guy that I got the car from he didn't touch any wiring other than stereo I cut apart non Factory tape on the harness trying to trace some wires I found butt connectors everywhere I found a harness with all black wires with half the wires coming out and looks like it's been hot everything just seems jacked I tried to follow the black Trace blue wire to the ECM and it seems to follow the main harness up towards the front. Wiring usually don't phase me one bit but dealing with somebody else's hack jobs really makes me upset I guess I just need to print off the diagrams and attempt to follow. Even though stuff that I'm seeing on the diagram that I have in front of me isn't matching what I have here Edited September 15, 2016 by Shortaay 1 Quote Link to comment Share on other sites More sharing options...
Shortaay Posted September 15, 2016 Author Share Posted September 15, 2016 (edited) Still won't start on starting fluid either so I have multiple issues going on I don't even know where to start especially saying the guy said that the car was running fine and then set for less than 2 months now I'm getting scared because I noticed what looked like Mouse residue in the backseat I'm hoping I don't have a wiring nightmare in front of me.... would me uploading pictures of what I'm seeing in this harness help anybody with giving me a diagnosis. Or a video? Edited September 15, 2016 by Shortaay Quote Link to comment Share on other sites More sharing options...
mudduck Posted September 15, 2016 Share Posted September 15, 2016 Have you checked all the fuses under the dash? I can't remember which one it isc number 5 i think it is, that will cause the symptoms your describing. Quote Link to comment Share on other sites More sharing options...
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