Infosecdad Posted February 28, 2019 Share Posted February 28, 2019 How are your OCV angles? still in sync? OCVs are very much in alignment. I pulled the #1 plug and scoped it, what I could see looked fine. I decided to just put it back together as the family wanted Chinese carryout. So I headed out to the market first, ran like crap. #1 misfiring to 50 and reseting. #3 misfiring continuously, rolling to 100 and looping around. 8 min drive, shuddering, just pissed off. Stop at the market, idle for a min, shut it off. Get a few things, come back out, start it up. Different car, smoother, minimal misfire. Stop at autozone, get a can of liquid moly injector cleaner, dump it in the tank. Idle and running continues to smooth out. Pick up Chinese, head home, running really smooth now. Last leg of the trip, nothing more than a 2 on #1... Honestly, I'm thinking the last fill up put some crap into that injector rail or something like that. I'll keep an eye on it, but hoping that's what it was. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted February 28, 2019 Share Posted February 28, 2019 That's interesting that this would have affected injectors only on that rail. Link to comment Share on other sites More sharing options...
StkmltS Posted February 28, 2019 Author Share Posted February 28, 2019 Sounds reasonable to think that a large enough piece of gunk stuck in the line (pre-fuel rail) might have an affect on the fuel flow going to both injectors. The likelihood of that being the problem seems highly unlikely so don't take this as my suggestion to tear apart a fuel rail My DiySB rebuild Got Misfires? Link to comment Share on other sites More sharing options...
Infosecdad Posted February 28, 2019 Share Posted February 28, 2019 (edited) Sounds reasonable to think that a large enough piece of gunk stuck in the line (pre-fuel rail) might have an affect on the fuel flow going to both injectors. The likelihood of that being the problem seems highly unlikely so don't take this as my suggestion to tear apart a fuel rail Not gonna now that it's running smoothly :-D That's basically the only scenario I can come up with as it started happening within a couple blocks of filling up. And it hit both injectors on that side. As it cleared up, it cleared on #1 in the front first, then for #3 in the back. The interesting thing is that the fuel delivery is sequential. It flows through #2, #4, #1, #3... So if something got in, it made it cleanly past 2/4 before mucking something up before 1/3, then got past #1, and finally cleared on #3. Whether it returned back to the tank or dissolved don't know. I removed the pulse dampener from the return line when I went to an STi FPR so it can't get stuck there. Edited February 28, 2019 by Infosecdad Link to comment Share on other sites More sharing options...
xt2005bonbon Posted February 28, 2019 Share Posted February 28, 2019 That's crazy. And that was Shell gas, supposedly good gas? Link to comment Share on other sites More sharing options...
StkmltS Posted February 28, 2019 Author Share Posted February 28, 2019 I'm all about jumping to conclusions and spending money based on assumptions (see my build thread), but let's not blame Shell just yet. Remember, the single thing that protects our cars from certain destruction comes from Shell... the almighty Rotella 5w-40. It could have been a chunk 'o gunk that was floating around in there from another fill up. My DiySB rebuild Got Misfires? Link to comment Share on other sites More sharing options...
xt2005bonbon Posted February 28, 2019 Share Posted February 28, 2019 You are right. Link to comment Share on other sites More sharing options...
Infosecdad Posted March 8, 2019 Share Posted March 8, 2019 (edited) Ok, looks like I'm back for more... Running smoothly, then bam! idling like crap. Misfires on #1 and #3 again. Then clears for a while, then returns. Temp, humidity, stuff like that doesn't seem to play a part. I replaced the #3 injector with one from my original set, didn't change the behavior. Most of the time, she runs really smooth, idles smoothly, great power, just a joy. About 1 of 3 trips, she loses her mind (at least for part of the trip). Yesterday, I needed to go to Costco, about 5 min into the drive, she just goes mad. #3 is misfiring badly, worse under load. Even when misfires are registering, the engine is bucking like it's on three cylinders. Running really rich, can smell the gas, tail pipes were all sooted, backfiring when letting of at times. Sometimes #1 joins in, but this time #3 (with a replaced injector, new plugs, and new coil) is the primary. Get to Costco, mutter all sorts of stuff, go get the few things I need. Come out, start her up, purrs like a kitten. Drives like a dream for 15 min, then loses her mind for about 2 min, then back to super smooth. I'm beating my head against the wall trying to figure out what could be root cause. - It's only ever effected the passenger bank (#1/#3) - Sometimes one cylinder, sometimes both - When it's happening, the engine is running really rough (like missing a cylinder) - It can run really rough without registering any misfires - When rough, it feels like it's dumping fuel (or at least not burning it) Right now, it seems to me that a certain condition is met, the ECU freaks out and it all goes down hill. Makes me wonder if a sensor is starting to freak out. - front 02? Wouldn't that impact more that just that bank? - cam sensor? Could the cam sensor on that side be responsible for this? (probably not) - Something telling the spark plug/coil to stop firing? That would explain the strong fuel smell, rich conditions, and backfiring... - ???? sensor? And no, I haven't checked valve clearance yet. I'm not convinced that could be it based on the really intermittent behavior. I've thought about a valve sticking open, but it would be weird to have it on two cylinders. Continuing research, I'm thinking about what could be responsible for two cylinders on one side to stop firing the plug... Thoughts, ideas? Edited March 8, 2019 by Infosecdad Link to comment Share on other sites More sharing options...
rhino6303 Posted March 8, 2019 Share Posted March 8, 2019 Ok, looks like I'm back for more... Running smoothly, then bam! idling like crap. Misfires on #1 and #3 again. Then clears for a while, then returns. Temp, humidity, stuff like that doesn't seem to play a part. I replaced the #3 injector with one from my original set, didn't change the behavior. Most of the time, she runs really smooth, idles smoothly, great power, just a joy. About 1 of 3 trips, she loses her mind (at least for part of the trip). Yesterday, I needed to go to Costco, about 5 min into the drive, she just goes mad. #3 is misfiring badly, worse under load. Even when misfires are registering, the engine is bucking like it's on three cylinders. Running really rich, can smell the gas, tail pipes were all sooted, backfiring when letting of at times. Sometimes #1 joins in, but this time #3 (with a replaced injector, new plugs, and new coil) is the primary. Get to Costco, mutter all sorts of stuff, go get the few things I need. Come out, start her up, purrs like a kitten. Drives like a dream for 15 min, then loses her mind for about 2 min, then back to super smooth. I'm beating my head against the wall trying to figure out what could be root cause. - It's only ever effected the passenger bank (#1/#3) - Sometimes one cylinder, sometimes both - When it's happening, the engine is running really rough (like missing a cylinder) - It can run really rough without registering any misfires - When rough, it feels like it's dumping fuel (or at least not burning it) Right now, it seems to me that a certain condition is met, the ECU freaks out and it all goes down hill. Makes me wonder if a sensor is starting to freak out. - front 02? Wouldn't that impact more that just that bank? - cam sensor? Could the cam sensor on that side be responsible for this? (probably not) - Something telling the spark plug/coil to stop firing? That would explain the strong fuel smell, rich conditions, and backfiring... - ???? sensor? And no, I haven't checked valve clearance yet. I'm not convinced that could be it based on the really intermittent behavior. I've thought about a valve sticking open, but it would be weird to have it on two cylinders. Continuing research, I'm thinking about what could be responsible for two cylinders on one side to stop firing the plug... Thoughts, ideas?Pins at the coilpack wiring harness? Link to comment Share on other sites More sharing options...
Infosecdad Posted March 8, 2019 Share Posted March 8, 2019 Pins at the coilpack wiring harness? I've played with them. I had to replace the connector for #3 before. I have tweaked the pins and the connector is zip tied, but maybe it's still having intermittent issues... ??? Maybe I'll try to mess with that again this weekend. Link to comment Share on other sites More sharing options...
Infosecdad Posted March 10, 2019 Share Posted March 10, 2019 (edited) Still pretty frustrated. Can't figure out what exactly is causing this. It's now coming and going multiple times in a trip. Can be smooth, then rough; once it's rough and there is any load I get a pile of misfires. Usually just #3, but if I push it at all (like uphill), then I can get #1 and #3 to misfire in sync. Thoughts about it are: - TGVs: Maybe they are doing something to mess up that bank? Not sure if there is much they can do, might do a delete anyway. - Fuel Pressure Damper: They could impact the rail on that side. I checked mine and they seem to be ok, tried adjusting them, but hasn't seemed to make a difference yet. - Fuel pump: I'm starting to wonder if my fuel pump is having an issue. I replaced the stock with a AEM 50-1000 in May 2017. I don't think I did a double o-ring, but not sure. It's been fine for a long time, might try testing the fuel pressure. The thought is if it's losing pressure or dying, then #3 is last in line and doesn't get what it should; then if I push it and demand more, #1 has issue as well and it's the second to last injector. - Coil Harness Plug: Pretty sure this is not it, I've double checked them three times, and the behavior of it going 1 & 3 if pushed when rough also pretty much rules this out. Edited March 10, 2019 by Infosecdad Link to comment Share on other sites More sharing options...
SBT Posted March 10, 2019 Share Posted March 10, 2019 Sounds like more fuel delivery than spark, and the ECU is doing everything it can to mitigate the issue. I'd check your FP pump and dampner. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
Tschagfreebird151 Posted March 10, 2019 Share Posted March 10, 2019 Pins at the coilpack wiring harness?When was the last time you checked your spark plugs? Do you always run 93 gas or better? Have you ever done a compression test? Leak down test? In addition to checking your fuel pump. O2 sensors could also be acting up.. are you getting a bunch of codes? Sent from my Pixel using Tapatalk Link to comment Share on other sites More sharing options...
lilredwagon Posted March 13, 2019 Share Posted March 13, 2019 I was sort of having the same issue as you a little while back. First I looked for vac leaks. Then I changed all the related parts: plugs, coils, harness coil connectors, fuel pump, injectors, fuel filter... I think that was it. It ran better for a little while, and then the problem came back with codes for 1 and 3 again. Confident that I took care of the mechanical parts, I then turned to sensors. I cleaned the MAF, making sure to spray inside the hole, not just the bulb that's visible. Well would you look at that, it's way better. Pretty much solved the problem. It still hot starts rough, so I have a coolant temp sensor waiting to try. But otherwise, it sort of seems like a simple MAF cleaning did it. All the other parts were due, so I'm not worried about firing the parts cannon at it, but after all that it was just a dirty MAF. Link to comment Share on other sites More sharing options...
revilo Posted March 13, 2019 Share Posted March 13, 2019 My 04 JDM LGT-B is suffering from idle dips when coming off the gas. It'll drop to 3 or 400 RPM before stabilizing around 700, although it doesn't die completely. I've logged the car with a tactrix cable and the AF/R is showing over 20 as the rpm drops. Not getting any CELs. Plugs are new. What should I do next? MAF cleaning? Coil packs? Both? Or does this sound more like a vacuum issue? Link to comment Share on other sites More sharing options...
xt2005bonbon Posted March 13, 2019 Share Posted March 13, 2019 My 04 JDM LGT-B is suffering from idle dips when coming off the gas. It'll drop to 3 or 400 RPM before stabilizing around 700, although it doesn't die completely. I've logged the car with a tactrix cable and the AF/R is showing over 20 as the rpm drops. Not getting any CELs. Plugs are new. What should I do next? MAF cleaning? Coil packs? Both? Or does this sound more like a vacuum issue? do you have a light weight crank pulley and light weight flywheel? Link to comment Share on other sites More sharing options...
Infosecdad Posted March 13, 2019 Share Posted March 13, 2019 When was the last time you checked your spark plugs? Do you always run 93 gas or better? Have you ever done a compression test? Leak down test? In addition to checking your fuel pump. O2 sensors could also be acting up.. are you getting a bunch of codes? Sent from my Pixel using Tapatalk Spark plugs are new. 93 Shell or Costco Did a compression/leakdown a while ago, don't remember the numbers, but they were fine. I pulled the fuel pump, replaced the o-rings and filter. Put it all back together, no difference. Tested the fuel pressure, it's perfect at 43psi at idle and seems to be in the right ranges when revving. I've pulled the front O2 to force it into open loop to see if it's a sensor that's killing it, and it still has the issue (just doesn't record the misfires). Pulling the MAF really ticks it off, doesn't really want to idle then. I've thought about the coolant sensor, but I think we only have one on these cars and it seems to be spot on for temps. I've also thought about TGVs messing up, the sensors read good though. I need to drive it for 600 mile round trip next week, so trying to figure this out. It's not messed up all the time, just sometimes. When it goes, you can feel it; even without misfires. You can feel a "switch" thrown, and she starts bogging down and running rough. Under load misfires in #3 and sometimes #1 is in-sync with it. Then you can be driving and the "switch" flips again and she is liquid smooth. For the life of me I haven't figured out how to nail this down without firing more of a parts cannon at it... Link to comment Share on other sites More sharing options...
xt2005bonbon Posted March 13, 2019 Share Posted March 13, 2019 sounds like #3 is happening more often than #1. Then, you know what I would check next Link to comment Share on other sites More sharing options...
Infosecdad Posted March 13, 2019 Share Posted March 13, 2019 sounds like #3 is happening more often than #1. Then, you know what I would check next I do. But I don't know why it would be intermittent... I haven't found a decent explanation as to why valve clearance would be so intermittent and flip on and off like a switch and on two cylinders. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted March 13, 2019 Share Posted March 13, 2019 I know. One day, something slightly similar (but in a single cylinder) happened, where I got TONS of misfires in a given cylinder all of the sudden. And this was due to an injector not sitting properly, resulting in dumping tons of fuel. Limped home when it happened. Catted upipe was glowing red . And misfire counts were going nonstop 0-99. Link to comment Share on other sites More sharing options...
SBT Posted March 13, 2019 Share Posted March 13, 2019 Holy fuel-diluted-oil Batman! - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
xt2005bonbon Posted March 13, 2019 Share Posted March 13, 2019 Yeah, now that you mention, I drained the oil right away just to be safe. Link to comment Share on other sites More sharing options...
Infosecdad Posted March 14, 2019 Share Posted March 14, 2019 I worked on her for a number of hours yesterday/last night. I have most of the misfires from #1 gone. I had to replace the "cleaned/flow tested a year ago" injector with one of my older ones and it cleared up. The only time #1 misfires now is when I have a decent amount of load and #3 is mad. I'm pretty sure it's essentially sympathy pains bleeding over. I thought I found the issue when I found that the clip is busted on the #3 injector wiring plug. However, that wasn't it. I pulled the spark plug that is almost new to find that the gap was significantly less than .031. Re-gapped it, didn't make a difference. Redid the connector for #3, the pins for the coil definitely fit tight now, no change. The behavior now is that it will be running rough and sometimes registering misfire at idle. Most of the misfires are registered under load, even though it's running rough most of the time now. However, I can make a 5 min stop and when I get back out she runs perfectly for a while before returning to rough. Gas smell in the exhaust is strong, minor backfires, definitely not cleanly burning in that cylinder. After messing with it, definitely more consistently dogging and misfiring from #3. I picked up valve cover gaskets from the dealer. I'm going to reseat #3 injector one more time. And I think I'm going to pull valve cover and measure the exhaust valve clearance. I can't decide if I'm hoping this is it or not... Link to comment Share on other sites More sharing options...
xt2005bonbon Posted March 14, 2019 Share Posted March 14, 2019 The only time #1 misfires now is when I have a decent amount of load and #3 is mad. I'm pretty sure it's essentially sympathy pains bleeding over. ^I agree. So, there is something wrong with #3. Do you have a borescope? Link to comment Share on other sites More sharing options...
Infosecdad Posted March 14, 2019 Share Posted March 14, 2019 ^I agree. So, there is something wrong with #3. Do you have a borescope? I do... I plan to scope through the plug and the injector when I get into it next and see if I can find anything with the scope. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now