jrettenmayer Posted February 17, 2010 Share Posted February 17, 2010 Hello subaru experts! Question: I swapped an EJ (1990) into my EA wagon (1986). I can hear some noise in my speakers when the car is running, sort of a humming sound. The tone of the noise increases with engine RPM - somehow, I'm getting some sort of interference or something that is coming over the speakers. Any ideas what it could be? Quote Link to comment Share on other sites More sharing options...
sube101 Posted February 17, 2010 Share Posted February 17, 2010 i would check all of your grounds Quote Link to comment Share on other sites More sharing options...
jrettenmayer Posted February 17, 2010 Author Share Posted February 17, 2010 So...I did something I'm not sure others did - all my grounds are in the harness - I think it's engine connector E3 - plus a ground coming off the ignition relay. I don't think there were others. How should this harness be grounded? Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 18, 2010 Share Posted February 18, 2010 More powerful EJ alternator. You probably just need to ground the engine to the body better. If nothing else put an isolator on the power supply to the stereo. All my EJ grounds the stock ones through the harness....except for the Ig and Fuel relay wires. I don't think you did anything wrong. Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 18, 2010 Share Posted February 18, 2010 everything for the engine control should be grounded to the block. then the block grounded to the battery. you've probably got some interference. did you take your power sources from the same circuit as the stereo somewhere? Quote Link to comment Share on other sites More sharing options...
jrettenmayer Posted February 18, 2010 Author Share Posted February 18, 2010 No...power sources for the ECU came all from the 4 wires running to the ignition (IIRC). I'll get a better wire for grounding the engine block to the battery, and also to the chassis. The wire I've got on there now is only freaking huge and black and runs from the starter to the NEG terminal on my battery... Seriously, though...you think I need more/better grounds? There is another one, maybe 14 gauge wire, running straight off the NEG terminal and bolted to the block also. I'd think with the negative battery cable and that other ground, plus at least one good chassis ground, I'd be good. I DO remember reading in chux's writeup that poor grounding is a common problem in this swap...:sigh:. Looks like I'm not done yet. On a side note, maybe someone had some ideas for another problem I've been having: every so often, the EJ just dies (at low idle, usually when I'm slowing down and making a turn). Think I need a surge tank or something like that? So far, it's just fired right back up, so I don't think it's anything major. Quote Link to comment Share on other sites More sharing options...
jrettenmayer Posted February 18, 2010 Author Share Posted February 18, 2010 Wait, just read numchux's post more closely. "Everything for the engine control should be grounded to the block" - does this include the ECU? And how about the Select Monitor plug? Can't remember which one, or both, had a ground. I think I just grounded that under the dash to the framework for the steering column. Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 18, 2010 Share Posted February 18, 2010 yes, all grounds for the ECU should go straight to the block. this is how they're wired in the stock car. I've never had a car show abnormal symptoms as a result, but I've never wired it any other way. But I have seen a few sources (including the installation manual for my Link Standalone) that mention that grounding one part of the system through the chassis can cause a difference in resistance.....which is a bad thing. Quote Link to comment Share on other sites More sharing options...
renob123 Posted February 18, 2010 Share Posted February 18, 2010 yes, all grounds for the ECU should go straight to the block. this is how they're wired in the stock car. I've never had a car show abnormal symptoms as a result, but I've never wired it any other way. But I have seen a few sources (including the installation manual for my Link Standalone) that mention that grounding one part of the system through the chassis can cause a difference in resistance.....which is a bad thing. I just searched, but I didn't find anything on your standalone on USMB. I thought the Link went the way of the dodo. Is there a thread somewhere where you give specifics? I know this is a semi-hijack, but I think there's some value to the community here as well. Thanks. Jacob Quote Link to comment Share on other sites More sharing options...
jrettenmayer Posted February 18, 2010 Author Share Posted February 18, 2010 Interesting... How about the ground for the ignition relay? Quote Link to comment Share on other sites More sharing options...
Gloyale Posted February 18, 2010 Share Posted February 18, 2010 Seriously, though...you think I need more/better grounds? There is another one, maybe 14 gauge wire, running straight off the NEG terminal and bolted to the block also. I'd think with the negative battery cable and that other ground, plus at least one good chassis ground, I'd be good. I DO remember reading in chux's writeup that poor grounding is a common problem in this swap...:sigh:. Looks like I'm not done yet. Your engine is gournded well it sounds. But the Engine is mounted on rubber mounts. For the CHASSIS to be grounded, you need a couple good straps from the block to the body. There should be one in the Front/drivers side corner, and one that goes from the top of the trans to the firewall. Add as many others as you want. Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 18, 2010 Share Posted February 18, 2010 I just searched, but I didn't find anything on your standalone on USMB. I thought the Link went the way of the dodo. Is there a thread somewhere where you give specifics? I know this is a semi-hijack, but I think there's some value to the community here as well. Thanks. Jacob http://www.linkecu.com the one I have is a v4 LEM. and yes, relay as well. but, unless you separated it for some reason, it should be tied into the grounds for the ECU as well. Quote Link to comment Share on other sites More sharing options...
renob123 Posted February 18, 2010 Share Posted February 18, 2010 http://www.linkecu.comthe one I have is a v4 LEM. and yes, relay as well. but, unless you separated it for some reason, it should be tied into the grounds for the ECU as well. Thanks. I already knew about the site. I was just wondering if you had a thread going or something so I could see how it works on a Subaru. Jacob Quote Link to comment Share on other sites More sharing options...
jrettenmayer Posted February 18, 2010 Author Share Posted February 18, 2010 Thanks everyone for your replies. Sounds like I need to get some time to get my grounds done up better than they are now. I appreciate the help and all the knowledge! Quote Link to comment Share on other sites More sharing options...
ShawnW Posted February 18, 2010 Share Posted February 18, 2010 IT could be the fuel pump which I normally ground on the body of the pump itself. Quote Link to comment Share on other sites More sharing options...
renob123 Posted February 19, 2010 Share Posted February 19, 2010 Thanks everyone for your replies. Sounds like I need to get some time to get my grounds done up better than they are now. I appreciate the help and all the knowledge! It's more of a band-aid fix, and it will only work sometimes, but you could try a cheap ground loop isolator from Radio Shack. I have one in one of my cars, and it seems to help. Of course, it depends completely on your setup. Jacob Quote Link to comment Share on other sites More sharing options...
jrettenmayer Posted February 19, 2010 Author Share Posted February 19, 2010 Well, I fixed up a couple of grounds, including the one from the front drivers side of the block to the battery, and also ran the grounds for the IGN relay and the select monitor out and grounded them to the block, right where the NEG battery cable grounds. The noise is still in the speakers, though it's reduced somewhat, and everything seems to work a little "better" - lights seemed a little brighter, engine seemed a little more peppy... I'll check into the fuel pump. I grounded that to the chassis, and specifically to a screw under the rear seat. Where do others typically ground the fuel pump? Quote Link to comment Share on other sites More sharing options...
kingbobdole Posted February 20, 2010 Share Posted February 20, 2010 Is it a buzzing? Maybe be the spark plug wires or a bad coil as well. Quote Link to comment Share on other sites More sharing options...
jrettenmayer Posted February 20, 2010 Author Share Posted February 20, 2010 It's a humming sound. I'm going to try changing the ground for the fuel pump today and see if that helps. Where do you guys usually ground your fuel pump? Quote Link to comment Share on other sites More sharing options...
Don_Quixpunch Posted February 22, 2010 Share Posted February 22, 2010 You haven't mentioned what you've got in the way of amplifiers and such. But one thing that commonly gets overlooked is induction noise. If you have input level wires running alongside your main harness or a large power wire you can pick up a lot of noise through them. That's why the pros run power on one side of the car and signal on the other side. If that's not it, try looking at existing ground points for dirt and loose connections. Especially the ground for the head unit itself. Quote Link to comment Share on other sites More sharing options...
jrettenmayer Posted February 27, 2010 Author Share Posted February 27, 2010 I don't have any speakers other than the crappy stock speakers and I still have the crappy stock head unit too. The noise wasn't there before I did the EJ swap....I cleaned up/redid some of the grounds in the engine compartment, which helped the noise a bit. Someone mentioned grounding the fuel pump to itself (the chassis), so I might try that too. I don't think it's got a super ground right now, so I could probably improve that a bit. Quote Link to comment Share on other sites More sharing options...
Mykeys Toy Posted February 27, 2010 Share Posted February 27, 2010 For the stock stereo by all means just use the existing stereo wires. If you ever update/upgrade find a new place to ground the stereo. Your ground should be equivelant to all power sources. As for the block I dont know what size wire you used to go to the battery but the same rule applies. I personally upgraded to 4 AWG and get zero noise but Also have not done this swap. It is never a bad thing to go overkill on your grounds, especially when it comes to stereo goodies which is eventually the focus on all my vehicles.. I am obsessed I cat seem to stop myself. It is safer and much less chance to introduce ground loop or interference noise. Just my .02 Mike Quote Link to comment Share on other sites More sharing options...
Don_Quixpunch Posted February 27, 2010 Share Posted February 27, 2010 I'm not incredibly knowledgeable with the Subie wiring, but I've been tinkering with stereos for years. I still have an EA engine in my Brat, but I upgraded to a 100 amp alternator. I changed to larger ground cables along with the larger power cable. No noise at all. Historically, my main cause of interference has been dirty and loose grounds. Quote Link to comment Share on other sites More sharing options...
jrettenmayer Posted February 27, 2010 Author Share Posted February 27, 2010 I did upgrade my grounds, both from the block to the battery, and from the chassis to the battery. The EA has shielded cable for some of it's sensors and I cut and spliced it in one section, so there is a spot that is not shielded - I'm thinking this is the source of my noise perhaps. I dunno, but if it is, I guess I'll just have to live with it. Quote Link to comment Share on other sites More sharing options...
Don_Quixpunch Posted February 28, 2010 Share Posted February 28, 2010 If I were having that problem, the next thing I would look at is how clean and tight the ground for the stereo is. If it's too hard to get to, I'd just cut the wire and splice in a new ground. As long as you hit the body, it doesn't matter where it is. When I put my head unit in, I just ran a new ground wire. But the PO committed some pretty severe *********************ery in my cars electrical system. Quote Link to comment Share on other sites More sharing options...
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