Built motor @ 17psi misfire
09-23-2009, 11:12 AM
#21
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In my logs I didnt see timing being retarded. What im going to do first, is put 1 step colder plugs, and see if it still does it. For now, I lowerd my shiftpoint to slightly below 6k (stock is 6200RPM), so I dont get in the misfiring range. Either way I wont be doing many WOT runs if any, till I get this solved.
Haha, yea I do have a RMT setup. Its taken me a couple of years to have it running how I do now. That thing back there spools up with the least amount of effort, If i brake boost in 1st gear, id be able to get 20psi in 2nd. Actually by taking out the muffler alone I get the same boost in 2d as i get in 3rd (19--20). (dynomax superturbo muffler is pretty damn restrictive)
Haha, yea I do have a RMT setup. Its taken me a couple of years to have it running how I do now. That thing back there spools up with the least amount of effort, If i brake boost in 1st gear, id be able to get 20psi in 2nd. Actually by taking out the muffler alone I get the same boost in 2d as i get in 3rd (19--20). (dynomax superturbo muffler is pretty damn restrictive)
09-23-2009, 11:33 AM
#23
09-23-2009, 12:39 PM
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Well my exhaust is not quiet, thats for sure. no resonators, 2.5" from ypipe to the turbo (all wrapped). Turbos has 12cm exhaust housing, with I believe a 56mm compressor wheel. Here's a clip if ur interested, so you can get an idea of what it sounds like. http://www.youtube.com/watch?v=bTC2d...e=channel_page
09-23-2009, 12:40 PM
#25
I just got new plugs, havnt installed them yet however I checked my current ones and I already have 1 step colder (I guess I had changed them before, so that rules out, the plug being too cold). I am going to put in a fresh set of plugs either way.
09-23-2009, 01:15 PM
#30
I hope the new plugs work out.
If it turns out not to be a plug issue, double check all of your wiring and connections in your ignition system. If there is a slightly loose connection somewhere, there is a possiblity that a certain vibration resonance causes the connector to vibrate and interrupt the electrical connection. I would expect the issue to be a little more intermittent though if this were the case. Nonetheless, it is worth a shot. Also, double check any grounding points that you have. I have heard of strange things occuring due to a poor or degraded ground connection.
After that, I think the next place to look is to see if anything funny is happening with your turbos and/or air intake. Since it only appears to be happening in 2nd gear, it may be speed dependent or dependent on the rate at which your rpms are increasing. Does this occur if you roll through 6k rpm with less throttle/acceleration? Either way, if the new plugs and wire check don't solve the issue, let us know what A/F meter you are using and what wastegates are you using? This may be a long shot, but if the A/F meter is digital, perhaps it is not getting updated readings fast enough to catch a momentary issue in the air intake.
Also, some wastegates are known to have issues. For example, on my Garrett 3071 turbos (T25 turbine housings), GTM welded the rod that controlls the internal wastegate in order to keep the internal wastegate permantently closed, and they provided extermal wastegates with my turbo kit. I beleive that this decision was made based on previous wastegate issues that they encountered. In addition, the stock Greddy wastegate configuration is known to have boost control issues (usually boost creep) at the higher boost levels. That's why a lot of people use a wastegate relocation kit. Your problem does not sound like any boost creep issues I have heard of, but who knows.
If it is not the plugs, wiring or the turbos/air intake, the next place to look is your fuel delivery system. What fuel return system do you have? If you don't have a fuel return system, you probably should for you hp levels.
If all that is fine, then the next place I would look is your valve train. I would save that for last because it is the most work.
If it turns out not to be a plug issue, double check all of your wiring and connections in your ignition system. If there is a slightly loose connection somewhere, there is a possiblity that a certain vibration resonance causes the connector to vibrate and interrupt the electrical connection. I would expect the issue to be a little more intermittent though if this were the case. Nonetheless, it is worth a shot. Also, double check any grounding points that you have. I have heard of strange things occuring due to a poor or degraded ground connection.
After that, I think the next place to look is to see if anything funny is happening with your turbos and/or air intake. Since it only appears to be happening in 2nd gear, it may be speed dependent or dependent on the rate at which your rpms are increasing. Does this occur if you roll through 6k rpm with less throttle/acceleration? Either way, if the new plugs and wire check don't solve the issue, let us know what A/F meter you are using and what wastegates are you using? This may be a long shot, but if the A/F meter is digital, perhaps it is not getting updated readings fast enough to catch a momentary issue in the air intake.
Also, some wastegates are known to have issues. For example, on my Garrett 3071 turbos (T25 turbine housings), GTM welded the rod that controlls the internal wastegate in order to keep the internal wastegate permantently closed, and they provided extermal wastegates with my turbo kit. I beleive that this decision was made based on previous wastegate issues that they encountered. In addition, the stock Greddy wastegate configuration is known to have boost control issues (usually boost creep) at the higher boost levels. That's why a lot of people use a wastegate relocation kit. Your problem does not sound like any boost creep issues I have heard of, but who knows.
If it is not the plugs, wiring or the turbos/air intake, the next place to look is your fuel delivery system. What fuel return system do you have? If you don't have a fuel return system, you probably should for you hp levels.
If all that is fine, then the next place I would look is your valve train. I would save that for last because it is the most work.
Last edited by ttg35fort; 09-23-2009 at 04:11 PM.
09-23-2009, 01:23 PM
#32
I hope the new plugs work out.
If it turns out not to be a plug issue, I think the next place to look is to see if anything funny is happening with your turbos and/or air intake. Since it only appears to be happening in 2nd gear, it may be speed dependent or dependent on the rate at which your rpms are increasing. Does this occur if you roll through 6k rpm with less throttle/acceleration?
Either way, if the new plugs don't solve the issue, let us know what A/F meter you are using and what wastegates are you using?
This may be a long shot, but if the A/F meter is digital, perhaps it is not getting updated readings fast enough to catch a momentary issue in the air intake.
Also, some wastegates are known to have issues. For example, on my Garrett 3071 turbos (T25 turbine housings), GTM welded the rod that controlls the internal wastegate in order to keep the internal wastegate permantently closed, and they provided extermal wastegates with my turbo kit. I beleive that this decision was made based on previous wastegate issues that they encountered. In addition, the stock Greddy wastegate configuration is known to have boost control issues at the higher boost levels. That's why a lot of people use a wastegate relocation kit.
If it turns out not to be a plug issue, I think the next place to look is to see if anything funny is happening with your turbos and/or air intake. Since it only appears to be happening in 2nd gear, it may be speed dependent or dependent on the rate at which your rpms are increasing. Does this occur if you roll through 6k rpm with less throttle/acceleration?
Either way, if the new plugs don't solve the issue, let us know what A/F meter you are using and what wastegates are you using?
This may be a long shot, but if the A/F meter is digital, perhaps it is not getting updated readings fast enough to catch a momentary issue in the air intake.
Also, some wastegates are known to have issues. For example, on my Garrett 3071 turbos (T25 turbine housings), GTM welded the rod that controlls the internal wastegate in order to keep the internal wastegate permantently closed, and they provided extermal wastegates with my turbo kit. I beleive that this decision was made based on previous wastegate issues that they encountered. In addition, the stock Greddy wastegate configuration is known to have boost control issues at the higher boost levels. That's why a lot of people use a wastegate relocation kit.
Frankie945, they are copper plugs v-power, isnt the only different that the iridiums last longer? as far as performance do they differ? (iv read they dont, but no experience with comparing them)
Last edited by streetzlegend; 09-23-2009 at 01:25 PM.
09-23-2009, 01:43 PM
#34
Yea I am going to try the new plugs and see what happens. I am using an LC1 wideband, and a TIAL 38mm WG. Id like to add to wat you mentioned "dependent on the rate at which your rpms are increasing" + given that boost level, since it does not do it at lower pressure.
Frankie945, they are copper plugs v-power, isnt the only different that the iridiums last longer? as far as performance do they differ? (iv read they dont, but no experience with comparing them)
Frankie945, they are copper plugs v-power, isnt the only different that the iridiums last longer? as far as performance do they differ? (iv read they dont, but no experience with comparing them)
Also, do you have a fuel return system? If so, which one? If you don't have a fuel return system, I have another thought about a potential issue. Let us know.
Last edited by ttg35fort; 09-23-2009 at 04:10 PM.
09-23-2009, 02:00 PM
#35
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I did a quick search on plugs cooper vs iridium.
https://my350z.com/forum/forced-indu...ilt-motor.html
https://my350z.com/forum/forced-indu...per-plugs.html
https://my350z.com/forum/forced-indu...ilt-motor.html
https://my350z.com/forum/forced-indu...per-plugs.html
09-23-2009, 02:19 PM
#36
I updated the post. Double check all of your wiring. It may be a long shot, but it won't cost any money for you to check this yourself. As I noted, poor and degraded ground connections sometimes cause strange issues to occur.
Also, do you have a fuel return system? If so, which one? If you don't have a fuel return system, I have another thought about a potential issue. Let use know.
Also, do you have a fuel return system? If so, which one? If you don't have a fuel return system, I have another thought about a potential issue. Let use know.
Frankie, like I had mentioned based on those two links, the iridiums really dont have added benefit, other than lasting longer.
09-23-2009, 03:45 PM
#37
I have a "return fuel system", basically us maxima guys who put in vq35's run the feed line into a T, one leg goes into an AFPR (the output of the FPR goes to the return line to the tank), and the other leg feeds the fuel rail. What do you have in mind? If it was a fuel issue, wouldnt it be leaning out?
Frankie, like I had mentioned based on those two links, the iridiums really dont have added benefit, other than lasting longer.
Frankie, like I had mentioned based on those two links, the iridiums really dont have added benefit, other than lasting longer.
Is the fuel system is installed in accordance with the manufacturer's recommend installation? Your installation method seems different than the fuel return systems I have seen. That doesn't mean it's wrong, but I would double check that. Here is a link to AAM's installation, with pictures. Based on these pictures, it appears to require a different type of installation than what you described.
http://www.alteredatmosphere.com/man...ion_Manual.pdf
Look at page 17. They have the fuel coming into the fuel rails. The exit from both fuel rails go into a "T", and then into the fuel pressure regulator. I beleive that the CJM motorsports FRS uses the same configuration.
I don't know if that is where your problem lies, but it is worth looking into. If your fuel rails are closed at one end, issues may arrise. Marren Fuel Injection makes hydraulic pulsation dampers, which may help. Here is the link:
http://www.injector.com/fueldampers....1806e89303b758
For the way you have your fuel rail system configured, maybe these will help. Nonetheless, I think it is a band-aid. Double check whether you have installed the fuel return system the way it was intended to be installed. If the issue turns out not to be the spark plugs or the wiring, that is the next thing I would look at. The Tial wastegates address concerns I may have had regarding a wastegate issue, assuming they are properly installed for your level of boost. In other words, my Greddy TT kit had Tial wastegates, but I still needed a wastegate relocation kit to get high boost without boost creep. But as I said, the description of your problem does not correspond to any boost creep problems I have heard of.
Last edited by ttg35fort; 09-23-2009 at 04:00 PM.
09-23-2009, 04:04 PM
#38
If it is a fuel issue, it would be leaning out. If it is only leaning out momentarily, perhaps it happens quick enough to go undetected by the AFR meter. That would depend on the AFR meter's sampling rate.
Is the fuel system is installed in accordance with the manufacturer's recommend installation? Your installation method seems different than the fuel return systems I have seen. That doesn't mean it's wrong, but I would double check that. Here is a link to AAM's installation, with pictures. Based on these pictures, it appears to require a different type of installation than what you described.
http://www.alteredatmosphere.com/man...ion_Manual.pdf
Look at page 17. They have the fuel coming into the fuel rails. The exit from both fuel rails go into a "T", and then into the fuel pressure regulator. I beleive that the CJM motorsports FRS uses the same configuration.
I don't know if that is where your problem lies, but it is worth looking into. If your fuel rails are closed at one end, issues may arrise. Marren Fuel Injection makes hydraulic pulsation dampers, which may help. Here is the link:
http://www.injector.com/fueldampers....1806e89303b758
For the way you have your fuel rail system configured, maybe these will help. Nonetheless, I think it is a band-aid. Double check whether you have installed the fuel return system the way it was intended to be installed. If the issue turns out not to be the spark plugs or the wiring, that is the next thing I would look at. The Tial wastegates address concerns I may have had regarding a wastegate issue, assuming they are properly installed for your level of boost. In other words, my Greddy TT kit had Tial wastegates, but I still needed a wastegate relocation kit to get high boost without boost creep. But as I said, the description of your problem does not correspond to any boost creep problems I have heard of.
Is the fuel system is installed in accordance with the manufacturer's recommend installation? Your installation method seems different than the fuel return systems I have seen. That doesn't mean it's wrong, but I would double check that. Here is a link to AAM's installation, with pictures. Based on these pictures, it appears to require a different type of installation than what you described.
http://www.alteredatmosphere.com/man...ion_Manual.pdf
Look at page 17. They have the fuel coming into the fuel rails. The exit from both fuel rails go into a "T", and then into the fuel pressure regulator. I beleive that the CJM motorsports FRS uses the same configuration.
I don't know if that is where your problem lies, but it is worth looking into. If your fuel rails are closed at one end, issues may arrise. Marren Fuel Injection makes hydraulic pulsation dampers, which may help. Here is the link:
http://www.injector.com/fueldampers....1806e89303b758
For the way you have your fuel rail system configured, maybe these will help. Nonetheless, I think it is a band-aid. Double check whether you have installed the fuel return system the way it was intended to be installed. If the issue turns out not to be the spark plugs or the wiring, that is the next thing I would look at. The Tial wastegates address concerns I may have had regarding a wastegate issue, assuming they are properly installed for your level of boost. In other words, my Greddy TT kit had Tial wastegates, but I still needed a wastegate relocation kit to get high boost without boost creep. But as I said, the description of your problem does not correspond to any boost creep problems I have heard of.
09-23-2009, 04:18 PM
#39
I am going to def look into the fueling, if the new plugs and wiring checks out ok. Now, say there was a problem with the fuel, in 3rd gear where the load is highest (compared to 2nd where im having the problem), wont there be a fuel problem in higher load, specially even at higher boost (20psi)? There is alot more fuel being used during 3rd gear, compared to where the misfiring is happening.
If it turns out the spark plugs and wiring are not an issue, the first step I would take would be to ensure that you have installed the fuel return system in accordance with the manufacturer's instructions. If your fuel return system is custom (as my new one will be), I would configure it like the AAM fuel return system. That configuration is well proven, and logically makes a lot of sense. If you don't want to do that, then I would try the hydraulic dampeners.
If the problem turns out not to be spark plugs or wiring, it is going to be a problem with your air intake, your fuel delivery, or your valve train. You have good wastegates, and I believe that any other issues with your air intake would be apparent in more circumstances that just 6k rpm in 2nd gear. The remaining candidates are fuel delivery and valve train. Since fuel delivery is much easier to address, that is where I would next look.
If you confirm that the spark plugs are OK, the wiring is good, the air intake system is good, and the fuel system is good, only then would I look at the valve train. If we get down to the valve train, I have things to look at. But let's not go there yet.
EDIT: I may be wrong, but I don't think it is the valve train. I don't think a valve train issue would only pop up in 2nd gear (though it is not out of the realm of possibilty). As others have said, the spark plugs are a likely candidate. If it is not the spark plugs, the wiring, or the air intake, the most likely candidate is the fuel system configuration. Actually, I suspect the fuel return system over the air intake, but the air intake system can be inspected without making a bunch of changes.
Last edited by ttg35fort; 09-23-2009 at 05:03 PM.
09-23-2009, 05:11 PM
#40
I'm looking at the rate at which the fuel requirements are ramped up. In 3rd gear, RPM changes, and thus changes in fuel requirements, happen more slowly than in 2nd gear. In 2nd gear, your RPMs build more quickly. If there is a hydraulic pulsation issue, perhaps the faster ramp-up will cause that issue to be more pronounced. That said, if you configure the fuel return system like AAM (and I think CJM) recommends, I think hydraulic pulsation will be less of an issue, if at all.
If it turns out the spark plugs and wiring are not an issue, the first step I would take would be to ensure that you have installed the fuel return system in accordance with the manufacturer's instructions. If your fuel return system is custom (as my new one will be), I would configure it like the AAM fuel return system. That configuration is well proven, and logically makes a lot of sense. If you don't want to do that, then I would try the hydraulic dampeners.
If the problem turns out not to be spark plugs or wiring, it is going to be a problem with your air intake, your fuel delivery, or your valve train. You have good wastegates, and I believe that any other issues with your air intake would be apparent in more circumstances that just 6k rpm in 2nd gear. The remaining candidates are fuel delivery and valve train. Since fuel delivery is much easier to address, that is where I would next look.
If you confirm that the spark plugs are OK, the wiring is good, the air intake system is good, and the fuel system is good, only then would I look at the valve train. If we get down to the valve train, I have things to look at. But let's not go there yet.
If it turns out the spark plugs and wiring are not an issue, the first step I would take would be to ensure that you have installed the fuel return system in accordance with the manufacturer's instructions. If your fuel return system is custom (as my new one will be), I would configure it like the AAM fuel return system. That configuration is well proven, and logically makes a lot of sense. If you don't want to do that, then I would try the hydraulic dampeners.
If the problem turns out not to be spark plugs or wiring, it is going to be a problem with your air intake, your fuel delivery, or your valve train. You have good wastegates, and I believe that any other issues with your air intake would be apparent in more circumstances that just 6k rpm in 2nd gear. The remaining candidates are fuel delivery and valve train. Since fuel delivery is much easier to address, that is where I would next look.
If you confirm that the spark plugs are OK, the wiring is good, the air intake system is good, and the fuel system is good, only then would I look at the valve train. If we get down to the valve train, I have things to look at. But let's not go there yet.
I see what your saying about the fuel, I am using the stock fuel rail which has the dampers on it (Dont know how good those are). I actually purchased a fuel rail so that I can make my own plumbing but the rail does not fit (it hits the upper manifold, its a fwd manifold). But for sure I agree with you its something that should be upgraded if is the source of the problem.
I briefly went over my wiring and couldnt find anything that might cause a problem, all grounds look good, everything looks great. (i took my time wiring the emanage so i know thats perfect.).
I just lowerd the boost to 15psi, and let me tell you, the car pulls alot harder, pulls all the way to redline and it didnt misfire. Now this leads me to the following, you mentioned about checking the air intake. Can having an intercooler thats too small cause such problems?