It's been awhile but I finally got my car back up and driving. Issues with injectors and lack of time kept her down for close to a year... but the last step was reseating the egr gasket and now she is running, what seems like perfect... though there is an issue, I am getting 2 codes... P0302 and usually P1320

To confirm there is an issue with cylinder 2, when I pull the connectors of the coils it's the only one that doesn't change how the engine sounds.
Alright, so today i went thought the basics, swapped everything from cylinder 2 -> 4, checking the codes along the way (of course erasing old codes first). Everything being... injectors, plugs (new, put them in yesterday), coil packs.

I have looked at the service manual, and they are fairly generic codes so plenty of other things to check. Ill be renting a compression test, and fuel pressure gauge soon to rule those out...

the condenser clip broke so haven't been able to pull it for an Ohm check yet (if it's bad would it only cause 1 cylinder to be misfiring?)

crankshaft sensors were all checked.

I'm getting power to the coil pack, Ill have to check that there is continuity to the ecm.

Anyone have recommendations on the next few steps they would do?

 

When you say "running perfectly," does that mean you don't notice any vibration or lack of power while driving and/or idling? If that's the case, then maybe it's just an infrequent, occurrence? If the compression was bad enough that it was causing consistent misfire in that one cylinder, I would think you'd definitely feel it.
When you clear the codes, they come back immediately?

Condenser is not specific to cylinder 1. This is literally just a small (0.47 uF) capacitor between the 12V rail and ground that serves to suppress (filter) the high frequency transients that can occur on the 12V line due to the normal operation of ALL of the coil packs. It should, by definition, be very high resistance. That said, however, I've seen a few videos that show some pretty ugly connections to the condenser. Maybe not on the 96/97? but on the versions that are covered in tape in the engine wire harness. In any case, the point being, if it were not functioning as it should, you might be hearing some excessive ignition noise on your stereo AND it would be affecting all the coils equally. If anything, a bad condenser might contribute to un-due long-term stress on the transistors in the coil packs, but I really don't think it could be the cause of specific cylinder misfire. Probably at least worth checking the health of the connector.

If you've thoroughly convinced yourself that you've got a known good coil, injector, and plug (NGK) on cylinder 2, then there is one very "low-tech" test that you can do to convince yourself that the cylinder is actually getting spark. I've done this on my '96 (also manual), but it's definitely a last-resort, proceed at your own risk kind of thing. Current probes (and even old-school timing lights) are the more "appropriate" tools, but if you don't happen to have those laying around, then start by removing ONLY the coil pack in question. Next, find something suitably small and non-conductive to lay on top of the engine at the cylinder in question (a small, clean hand towel works fine). Take one of your old (assumed good) spark plugs and gently insert it into the business end of the coil you just took out. Re-connect the coil to the wire harness and lay it (with the plug installed) exposed on the towel in a good position where you can see the spark gap. The point is to position the coil and plug assembly so that the tip of the plug is sufficiently hanging "in the air" and not making contact with anything. At this point you need an alligator clip lead test wire, or some other appropriate clip-on insulated wire that you can connect between the Cathode (threaded metal part of the plug) and the engine block (to complete the circuit).

At this point, you can very briefly start the engine (i.e. use a helper), and if the coil from that cylinder is functional and getting signal, then you will very obviously see (and hear) the spark happening at the plug. Obviously don't do it for more than a brief moment. No need to be dumping un-burnt gas through the exhaust unnecessarily. Handy diagnostic on occasion, but if you're not comfortable doing it, then by all means don't. Seriously... make sure you have zero gas vapor anywhere.

If you really do have good spark and fuel, and the car is running "OK" except for the fact that you're getting the codes, then it just might be a sporadic ECU issue or connector issue somewhere, but what a pain trying to track down either of those. Make sure that plastic plug to the coil is in good shape and the wires coming into it don't look stressed. CRC electrical connector cleaner is a fantastic product to have around for any old electrical systems, if you find dirty connectors, but in my experience the actual connectors (unless broken) are rarely the issue.

Unfortunately, you're rapidly running out of other options. The pressure in the fuel rail affects all injectors equally. Certainly fine to check and see that you're getting good pressure and that the regulator is NOT leaking out it's vacuum port, but again, not going to be the cause of a single cylinder misfire. Your getting into serious "Murphy" territory here, along the lines of taking out a bad fuel injector, and then replacing it with a new injector that also turned out to be bad, etc. I will say, however, that I had an injector go completely off line (solenoid coil opened up) which caused the cylinder to get NO gas. Car ran horribly, but the computer threw ZERO codes over the course of limping it back home and starting it several more times. So I have to wonder if a partially clogged injector would even throw a code? Mine certainly didn't under those circumstances. Just for what it's worth.

Good luck!

_______________
'96 i30t, Manual 275K

 

Alright just checked, and there is a spark. If I didn't have a code then I would assume everything was running just fine. Took it for a test drive, there was no hesitation. Power range was juat fine, car ran strong. Listened to the injectors and they all sounds the same. Also, Coils packs are oem (never changed them).

 

Which brand of spark plugs did you install.
This is important.

 

Ngk 7090 g power platinum tip

 

Just drove it, 5 mile drive to destination the service light never turned on... let the car rest for a couple hours, go to turn on the car and 30 seconds later the service light kicks on, I didn't have my scanner with me. Going to check it but assumed it's still cylinder 2 misfire (p0302)

But the car seemed to drive good, and didn't stumble with the power from what I felt.

 

What a mystery! So it at least seems to be a consistent problem, and it's tripping the code with 2 sequential drive events. In other words, whatever is tripping the code is happening every time you drive the car. So a few more questions...
1. Can you still remove cylinder 2 coil plug and not detect ANY slowing of the engine speed? If things are working normally, you should definitely detect a slight drop in engine RPM when you separate the plug from the coil.
2. Have you looked at any live data from your scanner? How are the short and long-term fuel trims looking between the two banks?
3. You said the connector on the condenser capacitor broke, was this just in the course of your trouble-shooting this problem? Or was that something that you found had already happened. Do you notice any excessive engine "whine" with the stereo ON (it really should be dead quiet)?
4. Any other odd electrical things happening? Surging/flickering dome lights at various engine speeds? Headlights dimming when the A/C compressor kicks on? What's the age/health on the alternator?
5. Have you measured the DC voltage of the system with engine idling as well as up at 2-3K RPM?
6. Are you noticing any gas smells while driving the car. Or after it's been sitting shortly after driving? Excessively stinky exhaust? (i.e. potentially leaky, bad injector). Extended crank time after parking the car and then starting 30-45 minutes later could also be pointing to a leaky injector (although not the only cause of extended crank).
7. You said you already checked crank and camshaft sensors, and presumably they have never thrown any codes, so probably no issues there.

I seriously doubt this has anything to do with the fuel delivery system and is most likely an electrical issue, potentially a wiring issue. Did you say the car sat for a significant period? Looked for any signs of critter damage to wires? Definitely inspect wire harness ground connections to the block.

Just some thoughts

 

Alright just checked the codes from that drive. I got 2 new codes, p1445(manufacturer control) and p0130 (02 sensors circut bank 1 sensor 1). That includes my other 2, cylinder 2 misfire and the p1320( manufacturer control)..... that was after I came home, let it sit again and erased the codes, only one that popped up after a few min wad the original 1320, not a misfire.

I find it vrry strange how the start of the day it drove without any service light popping on.

i pulled cylinder 2 and tho there is a bit of rpm drop, it's not as noticeable as the other cylinders.

Only drove about 10 miles, gauge didn't seem any lower.

No live data only using my ob2 scanner (what would I need to see live data?)

the condenser connector is fine, it's just the little tab that u have to push in to unplug broke off... so it's not ez to unplug, and I figured that only 1 misfire so it's probably not that, i broke it when tried to unplug, the plastic just broke immediately.

No electrical issues, I just installed a new alternator alittle bit before the car went under for the injector replacement.

I guess alittle bit of exhaust smell, I do think that I need to chsnge a gasket in the back of the car... possibly rear valve seal, i was getting some smoke from the back a few days ago, haven't seen it sense tho(it also was the first time letting it run for a bit in a long time)

 

P1445 (evap canister purge volume control). Definitely some diagnostic things you can do on that system to determine where the fault is occurring, but hard to see how it would be related to the original 1320. May be completely un-related.

Live data is feature of some of the more capable OBD2 readers such as this .
Handy for evaluating the health of O2 sensors and a lot of the other sensors/systems in real time. You can plot the data vs. time, which can be really informative. It's not a full scope, but certainly a nice tool for the DIY'er.

For example, if you have a bad injector issue such as insufficient gas or leaking too much gas, this will be reflected in the long-term fuel trims, which are treated separately per bank (bank 1, firewall, cylinders 1,3,5) (bank 2, radiator side, cylinders 2,4,6). I recently replaced all 6 injectors, (front 3 first, back 3 last for obvious reasons). Prior to replacement, both banks were reading positive 10 to 12% on the long term trims, indicating that the engine was running lean and the ECU was compensating by asking for more fuel from the injectors. Based on how clogged the screens were on the old injectors, this was not surprising. After replacement of the front three (all Hitachi, Rockauto), the trim values on bank 2 dropped to zero, while bank 1 remained the same. After replacing the back three, the bank 1 trims also dropped to zero, signaling that the air-fuel mixture is now almost perfect. There are certainly other things that can throw off the ratio (vacuum leaks, faulty mass-air flow sensor, bad 02 sensors, insufficient spark, etc.), but it's a very helpful tool in a situation like this to confirm that repairs were effective. The live data will also tell you things like how well the MAF sensor is working (no more guessing), Intake air temp, coolant temp, throttle position, idle rpm, timing, O2 sensor voltages, etc. etc. Obviously this is in addition to reading and storing trouble codes. But, back to the problem at hand...

I know you replaced at least one coil, but unfortunately, it's starting to sound more and more like you need to replace the full set in order to completely rule them out as the culprit for your p1320 code. You won't do much better than the Rockauto Hitachi parts ($37-ish each). I wouldn't buy parts like these from ebay or Amazon under any circumstance (just too much counterfeiting going on). And if you buy locally, make sure and get the Hitachis.
(OK... so re-reading your OP, you may have already replaced all the coils. However, if they were "off-brand," then unfortunately, you could still be running into a problem. It feels like a "throwing-good-money-after-bad" situation, which is a tough decision, AND it's entirely possible it wouldn't fix the issue).

Not surprising that you'd be burning off some residual oil seepage from an engine that's been sitting.

Also, if you clear codes, don't be surprised if you get nothing popping up on the first drive afterwards. A lot of these codes have a "2-drive" rule and have to occur on two sequential drives before they will register. Service manual will add some clarity there.

If you can confirm that your fuel trims (during closed-loop engine control) are within reasonable limits (+/- 12 % ish), AND the car is running well, then the reality is that you may have to decide how much money you want to throw at the "problem." If it's a gremlin-like electrical and/or coil issue, it's practically guaranteed that it will only make itself more apparent over time, at which point you might be able to fix with confidence. The joys of keeping the old cars on the road...always a trade-off between cost, time, and risk.

 

Few more drives around, everything feels just fine. Those new codes p0130 & p1445 haven't come back, weird. When I erase the codes, instead of the check engine light coming on right away, it stays off for the whole ride to a location but then it will kick on when I start the car up and drive back home.
Still got the cylinder 2 misfire. Going to get a compression test soon.
No significant difference in the gas consumption with these trips.