That kid has amazing hair.
GB, I already turned down my old iRacing team (Podium Assault) for that race. I love it but it's not to be this year. Good luck to your son's team! 24 hour sim races are awesome.
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That kid has amazing hair.
GB, I already turned down my old iRacing team (Podium Assault) for that race. I love it but it's not to be this year. Good luck to your son's team! 24 hour sim races are awesome.
Cool man... like I said, you never know unless you ask!
I wonder if DickDastardly (Simon) has iRacing...
;)
After 14.5 hours of racing, running in 10th place out of 25 Daytona Prototypes, my son got it wrong passing slower traffic while entering the bus stop. They came together, sending my son into the inside wall at 90mph. :( The repairs were going to take 55 minutes, so they packed it in.
They were doing pretty well. One of the guys dropped out, so there were only 2 of them on their team. My son completed 240 laps, his teammate had 234.
Just wait till next year!
Almost make me want to get into that...
Sounds stressful!!
Yeah, it's not easy. One of the hardest parts of a virtual 24H race is keeping all the drivers ready when they need to be. Stuff happens, pit stops get off sequence so there can be a lot to manage if some drivers are sleeping. Helps to have a global team, with a couple guys to cover the majority of their daylight hours.
350Z is throwing O2 sensor codes (first sensor, driver side + second sensor, passenger side) and a misfire code. It started trembling at idle a couple days ago. I've not had a chance to take a look at the car yet. Hopefully soon.
The car worked great last weekend on the rebuilt/shortened shocks:
https://www.youtube.com/watch?v=PCSs8ITDWgY
https://www.youtube.com/watch?v=flHBo8kBxcU
I have wanted to do a 24 hour online race, but my talent and time zone are not useful enough for anyone.
I'd look into the missfire first and foremost, the o2 codes are secondary to the missfire. When was the last time plugs were done on the car?
Went and checked things out for myself. Codes were cleared. Started engine. With A/C off the idle runs a few hundred RPM high for a period of time (I didn't time it - 30secs?), then lower for a period of time. As if the A/C was cycling on and off (but it isn't). As the engine warmed up the 'low' side of the idle (since it's alternating between two idle speeds - and to be honest I have no idea if this is new since the car runs with A/C on 99% of the time) went lower, down to 700RPM or so. Ran kind of rough but not too bad. Trembling a little. I thought the idle RPM was too low because when the RPMs would rise back up to the "high" level, the trembling would stop. So with my laptop I set the idle speed up 100RPM and... it still trembles on the 'low' RPM side even though the RPMs are high enough that they should be fine.
No more O2 sensor codes this time, just a P0300. "Random/multiple" misfire code. Most unhelpful, since I can't narrow it down to one cylinder. I did the cylinder de-activation test, switching off one cylinder at a time, and the car ran worse with each of them. So it doesn't appear to be one particular cylinder causing a problem.
Doing some reading, P0300 on these engines can mean just about anything, from fuel filter to PCV valve to vacuum leak to MAF and everything in between. Now I did put a new PCV valve in a couple weeks ago but that's pretty hard to screw up on these cars, and the hose is silicone so it's not leaking.
So this could end up being a long process.
The fact that it's subtle, and I can't narrow it down to one cylinder, seems to me to indicate something more "outside" the combustion chamber area, like a vacuum leak or dying MAF or something.
It's tough to know whether it's an A:F issue or spark issue. I had the same issue on the Volvo and the Jag - the Volvo was bad spark plugs and the Jag was the MAF. Plugging in an OBDII tool can help narrow down the problem if you can watch live data - check out the MAF flow rate, fuel trims, and 1st O2 sensor performance. Those will typically point you in the right direction. The bouncy idle does suggest A:F more than spark, but who knows?
I'd describe the idle more as switching between two speeds every ~30 seconds, rather than bouncing. What should I look for MAF readings, fuel trims, and primary O2 sensor readings? I know I can view at least some of that with UpRev data cable and Cipher software on my laptop. My OBDII scan tool is a $20 cheapie with no live viewing abilities.
T already had the MAF out yesterday, was going to clean it, but I looked at the element and it looks squeaky clean so I said not to bother. Maybe will try it anyway and see what happens. The misfire doesn't seem particularly bad, so I'm hopeful that idling the car from time to time isn't going to melt the cats.
Previous owner (meticulous on maintenance and quality parts) says he did the plugs shortly after he bought the car, so it wasn't that long ago. Still could be spark-related with a coil pack or connection somewhere.
Don't know if I mentioned it, but I'm theorizing the misfire led to the O2 sensor codes. O2 sensors usually exhibit different symptoms when they go bad, IME.
With the MAF you're looking for consistent response from a given throttle opening & engine speed.
This is a solid page on fuel trims: http://www.easterncatalytic.com/educ...agnostic-tool/
Typically, LTTF should be around 5%, but can go a little higher. Generally +/-8% or higher indicates a problem.
I don't know what type of O2 sensors are on the Z, but I'd assume widebands. They don't behave like narrow band sensors bouncing around, so you're looking for changing output with different engine behavior.
What codes are the O2 sensors throwing? I don't think there are too many scenarios when an upstream problem would cause an O2 sensor code. Codes are typically generated from faults (voltage out of range, nonresponse, heater failure, etc.) and not from valid though unexpected readings. That is, I don't think there are any O2 sensor codes a misfire could cause. Is it possible you have the opposite problem? A bad sensor causing goofy fuel trims that result in a misfire?
I suppose it's possible. It would seem unlikely that two out of four sensors, on different banks, on different sides of their respective cats, would go bad at the same time. When I did the testing with the laptop today, the O2 sensor codes did not come back (T had found them and cleared them yesterday).
More updates tomorrow, I suspect.
Edit - T remembered the specific O2 sensor codes. P0138 and P0152. High Voltage codes for Bank 1 Sensor 2, and Bank 2 Sensor 1, respectively.
I don't know this for certain, but I don't think a rich mixture will yield a high voltage code. I think that would just yield a P0175 or similar. The high voltage codes are for "off the scale" high voltages - that would be a fault in the ECM, the wiring, or the sensor itself. Maybe you have bad wire routing (headers?) and wiring got cooked? Wonky O2 sensors will *definitely* cause idle flux.
One of the wires was resting against the header. BUT, it's wrapped in this thick foil heat insulation stuff. That stuff was mildly burned, I peeled it back and the next layer looked perfect. That was the wire for Bank 2 Sensor 1. But could it mess up the wiring inside if the aftermarket heatshield wrap was only 50% compromised?
I figured out a way to ziptie that wire out of the way so it can't rest on the header anymore.
The other side has never been near the header but we got a code for that too.
If the header burned the shield, I suppose there is reason for concern the internal wiring could be damaged but it's impossible to know for sure without looking. If you have access to the sensor connector, I'd use a continuity tester to check between each of the presumably five wires. The high voltage code would typically be generated if a signal wire melted to a heater wire (you get 12v back on a 5v circuit). You should not get continuity on any pair of wires, though depending on your tester you might see it across the heating element. I agree it's very unlikely both banks got hosed simultaneously in this way.
Another scenario could be poisoning - if you've got a blown head gasket or put certain chemicals in the fuel that stuff can coat the sensor and create a high voltage. O2 sensors work by comparing oxygen levels in the exhaust to the atmosphere, and if the sensor is coated there will be nothing to compare, causing that abnormally high voltage. That's a pretty specific scenario, but it can exist.
If your scan tool can read the sensor output you'll be able to see what they're reporting and have a better idea of the nature of the problem. If you're getting 12v, you can be assured the heater circuit is backfeeding the sensor. ;) Do note that wideband sensors don't output 0-1v like narrowband sensors, they change current based on an reference voltage. Depending on what your scan tool reads, you may see their native output (in mA) or you may see the ECM reported values (typically in V). Less is richer, more is leaner. The ECM reported voltage varies from manufacturer to manufacturer, but I believe 3.3v is a reasonably common stoich reference voltage; 0-5v is the scale. If you're seeing under 5v, you have a high but attainable value. If you see greater than 5v, something is almost certainly broken (wiring, sensors, ECM, etc.)
I should have just driven my Altima to California and let you figure it out. I hope Cuda's car doesn't meet the same fate mine did :( #justsaynotocoldairintakes
I was trying to find Nissan's reference voltage but found this, a good read if you're curious:
http://www.diycardoctor.com/air_fuel_ratio_sensor.htm
I guess one advantage of having too many cars is that I am free to bang my head against problems basically forever and still get to work. I fought that Jetta for months trying to not have to buy a cat and got real close with reading O2 sensor feedback. Still had to buy a cat, but I did learn something. :)
What's wrong with cold air intakes, Keith?
From what I understand, the oiled filter on my cold air intake is the reason my MAF sensors kept dying, and the issues brought on by that were very similar if not identical to what eventually could not be rid from the car completely. Now I have a perhaps unwarranted fear of all intake modifications.
I think a lot of people go nuts with the oil. If you do it right there really shouldn't be any issues (but definitely still could be). I've had open K&Ns on Saabs since the '90s. Still, now that AEM etc. have dry filters, there isn't much reason to use a K&N anyway. :shrug: Still, given how much work manufacturers put into motors these days, I seriously doubt there is much to be had with an air filter change on most cars. I don't think anybody leaves much on the table anymore.
Cai is for the noise more than anything. Some simple math can prove that.
Oh yeah, I'm no fan of oiled filter elements either. Seen a few MAF sensor elements coated in black goop in my short time messing with cars. This stuff works pretty well for that. But still, I run dry filters when I can.
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So I did some datalogging now that I know a bit more about what to look for. I don't have access to fuel pressure data but MAF voltage seems fairly stable, and the one thing I did recognize as an anomaly is the O2 sensor behavior. The post-cat sensors both show constant 0.28v. The pre-cat sensors differ from each other, however. One goes back and forth from near 0v to near 1v (not quite reaching either). Slowly at idle, more quickly at ~2,000RPM. The other sensor moves from about 0.5v and 1.2v at idle, pretty slowly and with no detectable rhythm. At 2,000RPM it reads about 1.8v to 2.5v. That's Bank 2, which is driver's side if I can assume cylinders 2,4,6 are Bank 2. That's the sensor that had the toasty wire resting on the header.
I inspected the cats before starting the car and they look ok to me. The rear O2 sensors have a black appearance on the sensor element. No buildup.
So I am thinking replace the one O2 sensor and go from there. I'll also ask the PO when they were last replaced, see if I should really do them all ($$$). Worth noting I did hold RPMs around 2200 for 30 seconds to see if readings changed significantly, and once I let the car return to idle the trembling didn't return. Funny.
Here are the cats, looking towards the rear of the car. Left one shows some signs of melting but nothing too bad in my uneducated opinion. Right one looks perfect.
http://www.pbase.com/bryanh/image/162416163/original
You can also see the flatspot in the left one. Darn speedbumps. :x
WBO2 sensors don't behave like NBO2 sensors, they have a more gradual, linear response relative to input rather than bouncing voltages. The 0-1v is suspect IMHO. None of that is normal. The rhythmless one is a *more* normal behavior but still seems a bit off stoich from what I'd expect... IIRC you have an ECM tune so maybe that explains that. If it's not too much of a pain, before spending money you might consider swapping the two and seeing if the behaviors follow them. I don't know what the test is offhand, but you might check the heater circuits (with an ohm meter) - maybe the sensor(s) isn't getting up to temp, and once you've put some heat in it via the exhaust, it starts working better. Hey, at least the steady low voltage on the second sensors mean your cats are healthy! :)
Hm. Doing some reading, the RevUp VQs were the first ones to get wideband O2 sensors. The early VQ35DEs (like mine) have regular O2 sensors. Also the monitoring software, or the ECU, or whatever controls that readout, labels them "NB-O2 Sensor 1, Bank 2" etc. I think I have narrow-band O2 sensors. They have 4 wires each.
Good info!
Narrowband sensors operate between 0v and 1v, widebands are presented (via ECM) as 0v-5v. If you are seeing anything greater than 1v on a narrowband, something is wrong. I could very well be mistaken, but I don't think narrowband sensors are electrically capable of presenting >1v. So, yeah. something is wrong on that side - it's not an upstream issue.
I think it'd be worth swapping the O2 sensor connectors. It might make the engine a little screwy, but you will be able to see very quickly whether it's the ECM or its side of the harness, or the O2 sensor and its side.
The amount of wires does not denote if they are wide or narrow. the ECM will also not likely say WBO2. Look on the O2 sensors for a part number or something that you might be able to trace down, that will be about the only easy way to tell.
ECM or engine harness is unlikely IMO. Possible but unlikely. The engine bay is in pretty good shape, nothing's brittle or tattered. More likely the O2 sensor has failed or the wiring was baked by resting on the header.
I removed the offending sensor and unwrapped the heat shield material. The wiring has been extended, as I suspected. Seems some people are concerned with adding wiring length to O2 sensors and how different methods or materials (some say O2 sensor wiring is not copper?) affect resistance/voltage/whatever (someday I really need to take a class on electricity and learn this stuff proper!). I am probably just going to duplicate what is there so that it (presumably) matches the other side. Some folks use butt connectors but I'm not a big fan of those. I was thinking of using this project to get another soldering lesson from my dad.
New Denso sensor ordered. OEM is NTK but I felt like saving $30 and I think Denso usually makes decent quality parts. RockAuto was $60 shipped sometime in 3 to 9 business days, Amazon was $61 with Prime shipping and tax. Amazon it is.
Thanks as always for the ideas here. Every time I have an issue I learn something. I'll probably be pretty good at this car fixing stuff by the time I'm 80. :lol: But then I'll have to delegate due to geriatricness.
I used to worry about extending O2 sensor wire too, but after reading a lot during the initial days of Megasquirt and such I'm less concerned. On narrow band sensors, they are so inaccurate anyway that a little extra resistance isn't going to change anything. Widebands work on a totally different principle and aren't really affected by a typical extension. As long as you use appropriate wire and don't create a big resistance spot with your splice connection, it's just not going to matter in a meaningful way. Resistance of 18ga primary wire is about 6 ohms per 1000' - adding a couple feet in the middle of something is virtually electrically invisible. :) I do believe most O2 sensor wire is not copper, but the chassis-side wiring always is as far as I've seen. Adding a little copper to the sensor side isn't going to hurt anything. :)
Don't rule out butt connectors. In *general*, soldering is frowned upon in an automotive environment because the union is brittle and can be damaged by heat cycles and vibration. You will not find a lot of solder joints in a car - just lots of crimps. Crimped butt connectors are mechanically more secure and using quality butt connectors will give a better, more reliable connection. I would personally recommend either Molex Permaseal or Posi Posi-Lock - the latter are what Bosch recommends, in fact, versus soldering. A cheaper approach is a non-insulated crimp union with heat shrink over it. Do not use those crap Radio Shack nylon-insulated butts - they are the worst of all worlds. :) If you do solder, make sure you also use heat-shrink - in addition to sealing out moisture which can cause corrosion and high resistance, it also mechanically reinforces the union. I've said it elsewhere, but Harbor Freight has *the deal* on their marine-grade (adhesive-lined) heat shrink.
I like the Denso O2 sensors too - I still buy Bosch sensors for the Euro cars for no good reason, but everything else has a Denso. Well, except for the Jag as its OE sensor is Denso. :) Actually, I buy a lot of Denso stuff and have never been let down.
Good stuff. :up: I'm a big fan of the Posi-Lock connectors that Crutchfield sells for car stereo installations, but the non-inline shape the wiring ends up with is not ideal for O2 sensor wiring. Interesting to see they make in-line stuff, too. I'll have to find some of that. And some additional length of wiring shroud (whatever it's called) to slip over the extended section.
Finally got the extension done. In-line Posi-Lock connectors, heat shrink tubing (had to use 1" diameter tubing to fit over the 4 Posi-Lock connectors but it worked), and braided sleeving. Plus the old heat wrap that was there before. Should be good for a while. :up:
Re-set the ECU, started it up and let it warm up while eyeing the O2 sensor voltage readings. All looked good. In fact the new sensor is making the older sensor on the other bank look a little lazy.
But I think we're back in business. No CEL codes and no trembling idle. It doesn't idle super smoothly so there may be yet a tiny issue, or it might just be a VQ on solid(ish) motor/tranny mounts thing.
You found your culprit. Saying the new sebsor makes the other look lazy is the key phrase I was looking to hear.
Wait...that was it? I could have fixed the Altima by just extending some sensor wires? Instead I'm making payments on a car that is smaller, slower, less comfortable and with worse mileage...but at least it has Bluetooth :|
I thought you had an ms3?
Nice fix! I love it when diagnostics point at a problem and that's actually the sum total of it! :D
If you watch the scan tool, you should get some good resolution on MAF and engine speed - helps to divorce what you feel from solid mounts from actual engine fluctuation. :)
The MS3 has slightly more torque, but the Altima (in its heyday) had more power since it doesn't fall off a cliff towards redline.
Keith, I've read on The Internet that this would fix that problem with your MS3. #threadjack
Dang, I didn't know they were getting that cheap
That better top end breathing only manifests itself in objective results above 100mph.
Remember, we're talking about the Altima that's listed at 240 crank horsepower vs the MS3 that frequently makes that much at the wheels. Altimas may have been rated conservatively so as not to take away from Maxima sales, but MS3s were rated conservatively as well.
Ok, so the Altima only *felt* faster rather than being faster.
It was still more comfortable (both the seats and the ride), had more interior space, a better turning radius, better (and automatic) headlights, bigger trunk and better real-world mileage.
I'll sign off on all the rest of that. Except automatic headlights, as I have a Grand Touring package car that includes auto HIDs and wipers.
You just need a bigger turbo, Keith. :D
Keith, I imagine something else must have been going on with your Altima if multiple mechanics couldn't fix it. Random misfires can be caused by any number of things. And I'm pretty sure driving it for very long in this condition would start to bring on other problems. In my case the UpRev engine monitoring software was able to tell me one O2 sensor was reading outside of its intended parameters. Now, I didn't know what the paramaters should have been until I learned from the conversation in this thread. But now I know a few more things than I used to. :)
People say working on modern cars is tough, but I have an easier time with it than working on old cars. Better metallurgy, better design, the ability to monitor systems and perform basic tests from a home laptop... the only downside is room to work, in some cases. I may own a classic car again in the future and it sends chills down my spine thinking about the endless rust, fluid/grease seeping, carburetor tuning, electrical gremlins and corrosion, etc.
Here's part of the log from after the sensor replacement. I held RPMs around 2200 for the first part of the test (after the engine was warmed up) and then let it idle for the second part.
Attachment 1582
Just for clarity, I replaced one O2 sensor. The O2 sensor wires were already extended because of the headers on the car, and because the sensor showing bad readings also had some of the wiring rest on the hot header by mistake, I decided to replace all the wiring as well as the sensor itself, just to be sure. I had to make my own extension to match the old one.
Heck, a downpipe and a reflash would have him building power almost til redline. I've got a full turboback and intake, but the biggest restriction is the downpipe.
Multiple mechanics (private and dealership) either wanted to swap engines, or charge me hundreds of dollars to take it apart to try and figure out which cylinder was misfiring, let alone what was causing it or trying to fix it.
When something in the top end is borked, replacing the short block (or more!) is not uncommon with dealers. It's generally faster and given that dealership mechanics mostly do warranty repairs, they don't tend to be all that experienced at rebuilding engines anyway.
At least I know that was VW/Audi's approach for first gen 2.0Ts that had eaten their camshafts after the cam followers with no replacement interval wore out.
If you still had the car I would have recommended looking for a shop that specializes in Zs or Nissans. They'd know their way around a VQ better and probably have a bit more enthusiasm for finding and solving the actual problem.
I ended up with Potenza S04s because cheapness won out, but they're probably a better street tire anyway (better rain rating).
So weird. Any car with sequential injection should be fairly easy to track down misfires with a good scan tool. I mean, the EFI knows there is one, it isn't hard to make it tell you which ones. I am generally sad for the state of mechanicism.
Since this is the Garage subforum...
I was offered free sturdy shelves with the caveat that I had to pick them up in Hanford (45 minutes away). I borrowed my parents' truck, brought back one rack for myself and turned around and got one rack for them. I've been needing to help them organize their garage anyway, mostly because I have a bunch of leftover stuff there from the 300ZX project.
Back to my garage...
http://www.pbase.com/bryanh/image/16...5/original.jpg
Starting to make room for the shelves
http://www.pbase.com/bryanh/image/16...6/original.jpg
In place
http://www.pbase.com/bryanh/image/16...7/original.jpg
Organized! Ish.
Now both of our garages have more space. :up: Theirs moreso than mine because I used some of my shelves more for quick access to things rather than stuffing them full for storage. Plus I previously had a couple very tightly and neatly Tetrised piles. Still, a big improvement in organization and access even if I didn't gain a ton of floor space. :) At least I got to move the shop vac out of the spare bedroom and into the garage where it belongs!
I could totally use a peg board for some of my tools. Maybe I could zip-tie the tool holders to the metal racks...
Sharp! :up:
Obviously you need more of 'em... ;)
Fresh out of room unless I banish a car to the outside, which ain't happening. :) No, what I need :D is a proper sized garage.
California is a huge state! But, anyone who wants to make the drive is welcome to whatever I've got.
My buddies and I used to co-rent a warehouse 2000' which was a pretty good deal. But, still kind of annoying when you are working on something that's 30 minutes away. That was a big component of getting the house that I got. Acknowledging I can't afford a house that has a 10 car garage, I can at least afford a house that has 20 car driveway. ;)