Bushwick Posted March 25, 2016 Share Posted March 25, 2016 While dealing with a no start engine that seems to have been the fuel pump, while hood was up, I could hear this very faint buzzing in the higher freq. spectrum. It's so faint, i can't tell which sensor is doing it, but suspect it's causing a battery drain as my couple month old battery only allowed about 15 seconds worth of cranking after not running for 2 days when the car was doing the no start yesterday. Best I can tell, the sounds seems to be coming top of engine, and seems loudest closer to the alternator area or rather behind it, slightly to the passenger side on the top of the engine. I can't feel it either, and it's hard to hear. Disconnecting the battery makes it stop. Key out and 15 minutes later it's still there. Connect battery and it instantly returns. Ideas? Quote Link to comment Share on other sites More sharing options...
TOONGA Posted March 25, 2016 Share Posted March 25, 2016 If this was an EJ engine swap into an EA older vehicle I would say the alternator is making the noise. This is because it is wired to permanent power (EA alternator) not switched power (EJ alternator). As I have no idea what car the alternator / engine is in this is the only advice I can give you. TOONGA Quote Link to comment Share on other sites More sharing options...
Bushwick Posted March 25, 2016 Author Share Posted March 25, 2016 It's a 95' EJ22 with an 11' EZ36 (130 amp) alternator retrofitted. IIRC, I only ran one wire to it (field on or whatever it's called) so it it'll charge when it gets the signal vs. rpm-based on/off, and should be off when engine is off? Think factory 95' was 2 prong, and the EZ alt is 3 prong, so 2 prongs are left alone. I can try unhooking the field on wire, as well as the 12v+ post and see if the sound stops or not. I was thinking it was a sensor up top the manifold area. Suppose I'll try unhooking sensors and see if it goes away, then report back. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted March 25, 2016 Share Posted March 25, 2016 IAC makes noise sometimes. Shouldn't be doing it all the time though. Poor ground connection maybe? 95 ECU grounds down at the back of the #4 runner at the base of he manifold IIRC. Quote Link to comment Share on other sites More sharing options...
TOONGA Posted March 25, 2016 Share Posted March 25, 2016 (edited) It's a 95' EJ22 with an 11' EZ36 (130 amp) alternator retrofitted. IIRC, I only ran one wire to it (field on or whatever it's called) so it it'll charge when it gets the signal vs. rpm-based on/off, and should be off when engine is off? Think factory 95' was 2 prong, and the EZ alt is 3 prong, so 2 prongs are left alone. I can try unhooking the field on wire, as well as the 12v+ post and see if the sound stops or not. I was thinking it was a sensor up top the manifold area. Suppose I'll try unhooking sensors and see if it goes away, then report back. Ok I would say it is the alternator making the noise. As you have wired in a non standard alternator. Check that the power to the wire you ran to the alternator is off when the ignition is off, if not find one that is switched power and this should solve the problem. TOONGA Edited March 25, 2016 by TOONGA Quote Link to comment Share on other sites More sharing options...
Bushwick Posted March 25, 2016 Author Share Posted March 25, 2016 Sound seems to be ahead of the IAC and ahead of TPS, but behind the alt. It's extremely quiet and suspect most wouldn't even hear it. My upper hearing hearing range is 16 khz, and it sounds close to that range, like a test tone sine wave in the 12-14 khz range. I'll try unhooking things later as it's going to be random guessing game. Was hoping to hear an "Oh yeah, that's a known issue, it's the thingamajiggy" to avoid wasted unplugging. Thankfully there isn't too much going on there, but some of the sensors might take a little time to get unhooked, and I'll try and rule alternator out 1st. I reused the factory signal on wire for the alt, so it's turning on the signal just like it would for the factory alt and should be going off with the key off if that's what it did from the factory. I think one terminal is unused and the other is a low voltage indicator for a dummy light, but not 100% certain. Quote Link to comment Share on other sites More sharing options...
TOONGA Posted March 25, 2016 Share Posted March 25, 2016 So I did a little search on that alternator and found this http://forums.nasioc.com/forums/showthread.php?t=1323800&highlight=EZ30&page=113 it may help you. I still believe the alternator is on, hence the noise you are hearing. I have had the same problem with an EJ22 in a brumby and an EJ22 in an XT / vortex. Both times the problem was fixed by changing the way the alternator was wired. TOONGA Quote Link to comment Share on other sites More sharing options...
Bushwick Posted March 26, 2016 Author Share Posted March 26, 2016 (edited) The alt on wire is remaining hot. Probed with key off and it's doing battery voltage. Disconnected it (it shorted briefly after slipping from fingers) and didn't blow a fuse? Was still showing the 12v+ signal. However, the alt is NOT making the buzzing noise (or at least not directly) as the sound still remained. Wasn't as windy out and I was able to get ear closer and trace the buzzing to the IAC? I unhooked it and the sound stopped. I could also hear what sounded like the IAC moving after it's connector was pulled (it was creaking). Any ideas on what's going on? I was thinking maybe the field on wire for the alt was keeping 12v+ in the system when it's supposed to be off, but then I suspect it would have stopped the buzzing, which it didn't. So IAC is staying energized 24/7. Kinda surprised it hasn't burned out and quit working yet. EDIT: Fairtax, do you think a ground issue would be keeping the IAC on? Car has been sitting for roughly 2 days, so that buzzing isn't going away on it's own. Battery voltage was 11.38v before car was started, so there's definitely a drain on the system. Edited March 26, 2016 by Bushwick Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted March 27, 2016 Share Posted March 27, 2016 IAC is moving all the time when the engine is running so it spends all of its time with current running through it. It's designed to do that on top of a hot engine, so doing its thing on a cold engine that isn't running is like a cake walk. The ECU powers the IAC IIRC, so if the ECU isn't turning off, the IAC will still be getting power even if the engine isn't running. Try plugging a code reader into the DLC and see if it connects to the ECU with the key off. It should power up, but not be able to connect. If it does connect the ECU is staying live all the time, and that could be due to a couple reasons. If it's not staying live, a bad ground for the ECU could cause current to backfeed through other circuits in the ECU and cause those other circuits to remain On, even if the ECU is Off. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted March 28, 2016 Author Share Posted March 28, 2016 The ECM ground you stated connects near the number 4 runner, is it just screwed directly to the aluminum? Any idea what color the wire is? I was messing with the black ground jumper near the dog bone mount on top of the trans (I just moved moved it a bit) that seems to be an engine to body ground, and I couldn't hear the IAC. Can't really figure that one out as there should be other grounds from engine to body/battery and that wire would be melted if only strong ground left from starter cranking. It was hardened though, so that's due to be replaced, and I'm thinking of replacing a main ground or adding some redundant engine to body to battery heavy cable ground just in case, but can't figure out why the small ground jumper would have any effect whatsoever? Quote Link to comment Share on other sites More sharing options...
Bushwick Posted March 28, 2016 Author Share Posted March 28, 2016 I can't find that ground you were referring to Fairtax. No. 4 runner would be passenger side, nearest the firewall? I looked at both rear runners and saw no actual point. There are a group of connectors near there, but I didn't see anything terminated into metal. I also tried wiggling that ground jumper again and the sound didn't stop, so maybe I was imagining it going silent before. Bought a new negative battery post + 2 gauge cable x 48" to replace the the OEM one which is getting old, and also picked up a generic 4 gauge to replace the smaller jumper at the top of the trans near the dog bone which I've yet to install either, but would like to also repair or inspect/replace the ECM ground you were referring to, or possibly relocate it to the jumper ground so it's strong. Thanks. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted March 30, 2016 Author Share Posted March 30, 2016 Fairtax, you around? Can you specify where that ECM ground is? Is it part of a connector, or does it ground right to the runner? Can't find it. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted March 31, 2016 Share Posted March 31, 2016 Number 4 is drivers side rear. It's all the way at the base of the runner on the back side. 4 brown wires going to two eyelets, single bolt into the manifold. Look where the line from the fuel rail bends around and goes behind the manifold. It's under that. Hard to see, hard to get to, and probably covered in dirt and grime. I can try to get a pic tomorrow if that'll help. Also, check the 16 pin connector on the passenger side on the bellhousing. The bottom 4 pins are the same ground wires. Make sure they're clean and the connector is clicked together all the way. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted March 31, 2016 Author Share Posted March 31, 2016 Thanks FT. I'll follow your directions and try and find them. I was looking more towards the back of the runners. Can I just trace the wiring back from the 16 pin connector? Or does it make a bunch of detours? Quote Link to comment Share on other sites More sharing options...
idosubaru Posted March 31, 2016 Share Posted March 31, 2016 i've heard IAC's do this before, and it's been awhile but i think they only do it when the key is in the ignition (engine off). but i suspect you've probably already just unplugged the IAC as a test anyway right? get a mechanics stethoscope? i'd try to narrow down the issue before attempting a repair. i feel like a lot of times when i guess on weird issues it ends up wasting me a lot of time - though new grounds/wires wouldn't be a total waste! unplug the main engine harness - does it go away then? maybe that would differentiate engine harness/sensors with alternator/starter/cabling since those are separate harnesses (although it looks like you basically ruled out the alternator already)? i'd unplug every easy component in that area - coil pack, IAC, alternator, power steering connector, A/C connector, and any of the easy to reach solenoids. have you tested your parasitic battery draw yet - should be under 100 milliamps. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted March 31, 2016 Author Share Posted March 31, 2016 @Gary Yeah, IAC buzzes key-off. Definitely putting a drain on battery and by winter battery needed replaced (I thought battery was faulty as it cranked fine until it got cold). Unplugging IAC stopped the sound, which sounds like a higher frequency oscillation. Haven't tried any battery drain testing as I already know this is staying on. Too windy/rainy to mess with it today, so hopefully can get to it tomorrow. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted April 16, 2016 Author Share Posted April 16, 2016 Number 4 is drivers side rear. It's all the way at the base of the runner on the back side. 4 brown wires going to two eyelets, single bolt into the manifold. Look where the line from the fuel rail bends around and goes behind the manifold. It's under that. Hard to see, hard to get to, and probably covered in dirt and grime. I can try to get a pic tomorrow if that'll help. Also, check the 16 pin connector on the passenger side on the bellhousing. The bottom 4 pins are the same ground wires. Make sure they're clean and the connector is clicked together all the way. I still can't find that ground Fairtax. Do you happen to have a pic? Quote Link to comment Share on other sites More sharing options...
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