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Discussion Starter · #24 ·
I’ve made some more good progress.

So I just ran a new hose from the PCV to the intake manifold and left my oil catch can between the valve cover vent and intake pipe. I have a second oil catch can I can use between the PCV and intake manifold, but I’m going to leave that alone until I can fix all my other issues first.

I swapped the spark plugs between cylinders 2 and 4; cylinder 4 spark plugs was black and wet which tells me that fuel isn’t being completely burnt so it’s probably not making spark. I then got engine codes for high idle rpm, cylinder 4 misfire, and random misfire. There was definitely an issue at cylinder 4, and the random misfire was probably due to the dirty spark plug now in cylinder 2. I bought new spark plugs last night while racking my brain over the possible causes and gapped and installed them this morning. The high idle and misfire 4 codes still remained so I narrowed the issue down to cylinder 4 coil pack or connector. I checked all 4 connectors’ pin 1 voltage and pin 2 grounds and everything looked good. The issue was either the pin 3 signal from the ecu or the coil pack itself. To test this I pulled the cylinder 1 and 2 connectors off, removed the cylinder 3 and 4 coil packs and inserted spark plugs into them. I used jumper cables to ground the spark plugs to the negative battery terminal, and had my brother turn the engine while I watched the spark plugs.

Test 1:
Connector 3, CP 3, SP 3 = Good Spark
Connector 4, CP 4, SP 4 = No Spark
Test 2:
Connector 3, CP 4, SP 4 = No Spark
Connector 4, CP 3, SP 3 = Good Spark
Test 3:
Connector 3, CP 4, SP 3 = No Spark
Connector 4, CP 3, SP 4 = Good Spark

The common denominator here was the coil pack from cylinder 4, so this had to be the problem child. I was suprised because this was one of my BRAND NEW NGK coil packs. I replaced the bad coil pack with one of my old ones, took it for a test drive, and the misfire code is completely gone now.

I’m still left with the high idle RPM code, so I took my smoke machine out to check for vacuum leaks. Surely enough, I have a new leak at the front passenger corner of my valve cover. I must not have installed it correctly, so I’m going to head over to autozone and just get agasket to see if that’ll fix it.

It’s as close as it’s ever been to running right and I’m so excited. I still have a few smaller things to tweak; my side exhaust needs to be raised and my parking brake needs adjusted to prevent the car from rolling on an incline.
 

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Discussion Starter · #25 ·
The new valve cover gasket seems to be doing the trick. I installed it, ran the smoke machine again, sealed down a few looser connections over some of the hoses, and did the relearns. It seems to be running perfect, I just finished my first trip without any check engine light. I even had some guy in a Lancer try to chase me down in the backroads and we had some fun. He caught me at a stoplight and asked what I was running and what exhaust I had. With the exhaust coming out the side, I guess it probably is kinda funny to follow a quick noisy car with no visible pipes 😂
 

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Discussion Starter · #26 ·
Alright so I’m getting cylinder 4 misfire codes again. It was only happening at first when I the car was idling with AC off. Anytime there was any load on the engine it seemed to run smooth. The engine code would only come back sparingly if I let the car sit and idle for about 20 minutes or so. I bought another NGK coil pack to replace the old Hanshin coil pack I was using as a substitute but it didn’t seem to fix the issue. The problem seems to be progressively getting worse because the engine code is coming back more frequently when sitting and now it’s coming back while driving. I think there’s an electrical issue killing my coil packs somehow. Before my engine swap, I added a grounding jumper going from the battery to the head where the coil packs are grounded and from the head there to the alternator bracket ground. I removed the jumper to the alternator bracket, but that hasn’t seemed to change anything. I’ll try disconnecting the jumper from the battery to the head, if that doesn’t work then I may consider wiring new grounds from the coil pack connectors straight to the battery. I really wish I could get my hands on a spare 04-06 Spec V engine harness to replace the coil pack wiring with a larger wire size without sacrificing my original harness, but all the junkyards have is 1.8’s.
 

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Someone had a misfire due to the plug not being fully installed/torqued and it supposedly backed out iirc; another issue might be a faulty spark plug as well. Did you swap coil packs around yet?

Another one might be the injector as well, I'd swap it to a location that the coil pack isn't going to.
 

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Discussion Starter · #28 ·
Someone had a misfire due to the plug not being fully installed/torqued and it supposedly backed out iirc; another issue might be a faulty spark plug as well. Did you swap coil packs around yet?
Yea, spark plugs and coil packs are all brand new. Cylinder 4 is currently on its second new coil pack since the other new one stopped working. I gapped the spark plugs at .48 and torqued them all to 20 pound feet at install. I might pull the cylinder 4 spark plug out in just a minute to inspect it and see what’s happening. I believe some electrical issue is killing my coil pack and my spark is becoming weaker until the coil pack gives out, so I’m expecting the cylinder 4 spark plug to look black and wet again as a result of not burning fuel efficiently.
 

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Discussion Starter · #29 ·
I tried idling with and without the grounding jumpers, it doesn’t seem to change anything so I’m leaving them on.
So the car starts at 1200-1500 rpm and runs smoothly there. As it warms up and settles at 800-1000 rpm it noticeably and frequently misfires. Turn on the AC and it stays around 800 rpm and sounds smoother with less cabin vibrations, but it is less noticeably misfiring. You sorta have to be listening for it to notice it.
 

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Discussion Starter · #31 ·
Ok, so I didn’t pull the spark plug to look at it. Instead I swapped the new NGK coil back to the old Hanshin and it’s back to working almost perfectly. At idle it’s smoother overall, but again if you’re listening for the misfire then you can hear it. I just took it for a drive to get gas, and it’s got torque in low rpm’s that I was losing earlier this morning during my drive to and from church. I still think there’s a high resistance to ground issue with cylinder 4 compared to the other cylinders. This would make cylinder 4 coil pack draw more current to power the same electrical load as the other cylinders, and that high current/ resistance is probably causing more heat and electronic degradation. For whatever reason the Hanshin is handling the situation better than the NGK’s.
 

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Discussion Starter · #32 ·
I don’t really want to swap injectors because they’re “Professional Cleaned / Hot Tanked / Benched Tested / New Orings by Fuel Injector Connection - OEM” from 2JR. If I’m going to do the work to take the plenum off, remove injectors, and reinstall everything then I may as well look at upgrading injector size, swapping from my Altima to a Rouge plenum, and get tuned for e85. I already had a spare injector harness so I just swapped them and checked my fuel injector resistances just to be safe.

Injector resistance in ohms
1 - 14.3
2 - 14.7
3 - 14.5
4 - 14.4

Swapping the injector harness doesn’t seem to have changed anything yet. This is the most annoying check engine light yet so far because it seems like it’s so close to being right. Sitting at the gas station with the AC off earlier to write my last post gave the ECU the signal for a misfire check engine code before I left, but sitting here with the AC on writing this post hasn’t sent the signal and I’ve been here longer.
 

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So the car starts at 1200-1500 rpm and runs smoothly there. As it warms up and settles at 800-1000 rpm it noticeably and frequently misfires. Turn on the AC and it stays around 800 rpm and sounds smoother with less cabin vibrations, but it is less noticeably misfiring. You sorta have to be listening for it to notice it.
I have a similar problem. As you, idles fine until warm and settles then rough idle with occasional hiccup but no codes. Runs fine with plenty of low torque.
Have installed new cam & crank sensors, O2 sensor, coil packs and MAF but not been able to find problem yet. Suspecting vacuum leak.
 

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Did you try a noid light yet? Make sure the light blinks and is not a constant on any of the cylinders... you keeping an eye on the oil?
Make sure you ain't filling up with unburnt fuel.
You probably know all that already. Was reading up and was thinking possibly the injector wire harness but looks like you changed that out.
Kinda feels like wiring or computer.
 

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Discussion Starter · #35 ·
Did you try a noid light yet? Make sure the light blinks and is not a constant on any of the cylinders... you keeping an eye on the oil?
Make sure you ain't filling up with unburnt fuel.
You probably know all that already. Was reading up and was thinking possibly the injector wire harness but looks like you changed that out.
Kinda feels like wiring or computer.
I haven’t tried a noid light, that might be next on my shopping list..
I checked the oil early this weekend because the last time I checked it in early or mid-august it was low. This time the oil level was good, but it was a lot darker color than what I was expecting. I think I can attribute this to the motor running like shit when I had coil pack connectors swapped and the dead NGK coil pack installed. The oil isn’t old or high mileage yet, it was fresh changed when I swapped the engine. I probably should get some fresh oil in just to be safe.
I’m going to stay on the lookout for SE-R or spec V’s in junkyards, or maybe get an ECU or harness off of eBay somehow.
 

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I can check pull a part by me and see what they got up there. If that oil don't smell like gas we can probably rule out an injector over spraying. I was thinking for the hell of it put some iridium plugs in (not sure what you got in there now) iridium plugs don't tax your electric as much as others. You were saying it's better with ac on. That makes me think when the alternator is kicking your getting some extra juice in the system. Either pushing through the problem or just masking it. Possibly with iridium having less electric draw may do something for you. But I'm just guessing from my house. Hard to see from here lol.

I'll try to get to pull a part Saturday and see what's up there. As far as years what can you use? Just 04...

One more thing that probably means nothing. Mine is a 04 spec v, when I bought it the first month I was chasing an electrical problem. Car ran like shit but also killed the battery after about 4-5 days sitting. Never really figured out the why but I changed my dash cluster and it fixed everything. Then I found this place and seen there where differences between years and alarms I guess I got lucky because I don't even remember what year I yanked this cluster from but it works.

I'll go rack my brain some more, see if I can think of something
 

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Discussion Starter · #37 ·
I can check pull a part by me and see what they got up there. If that oil don't smell like gas we can probably rule out an injector over spraying. I was thinking for the hell of it put some iridium plugs in (not sure what you got in there now) iridium plugs don't tax your electric as much as others. You were saying it's better with ac on. That makes me think when the alternator is kicking your getting some extra juice in the system. Either pushing through the problem or just masking it. Possibly with iridium having less electric draw may do something for you. But I'm just guessing from my house. Hard to see from here lol.

I'll try to get to pull a part Saturday and see what's up there. As far as years what can you use? Just 04...

One more thing that probably means nothing. Mine is a 04 spec v, when I bought it the first month I was chasing an electrical problem. Car ran like shit but also killed the battery after about 4-5 days sitting. Never really figured out the why but I changed my dash cluster and it fixed everything. Then I found this place and seen there where differences between years and alarms I guess I got lucky because I don't even remember what year I yanked this cluster from but it works.

I'll go rack my brain some more, see if I can think of something
So when I originally swapped the engine in, I had installed NGK iridium plugs and gapped them at .44”. When I went to re-gap them to .48” I had bent the center electrode on 2 of them, so I replaced them with NGK platinums for peace of mind. I could try the iridium’s again but I don’t think it’ll make a huge difference; it behaved similarly with either type.

I’ll stop being stubborn and probably swap injectors this weekend if I can get all the new gaskets I need. I don’t think it’s the issue, but it’s best to be 100% sure before going forward.

I’m pretty sure any 04-06 Ecu and harness should work. I see plenty of ECU’s on eBay but no harnesses so it seems like a junkyard visit to grab both is inevitable as long as I can rule out my fuel injector as the issue. I’m going to check the inventories of the junkyards around Tennessee daily, but if you find an SE-R before I do then I’ll try to make it worth your trip.
 

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Couldn't tell you as the known difference is a wideband inplace of a narrow band for the up stream o2, could be more but don't see why not
 
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