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perspectiveshifting

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  • Location
    Bothell, WA
  • Cars
    1972 240z
  • Interests
    Music

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  1. TDC has been confirmed via the number one spark hole, and aligns with timing mark on car. Very possible something is causing me to misread it some way I'm not aware of, but the crank pulley and timing indicator do appear to be at TDC when the piston is.
  2. I've effectively completed an engine swap on a 1973 240z, and am running into what I hope to be my last roadblock in the process. Despite my best efforts, I can't get the timing anywhere near normal on it. It runs at its current setting, which clocks in at about 55 degrees advanced, but lags tremendously at higher Rpms. Attempting to lower the advance results in the engine refusing to start, and also requires shifting the spark wires to a different position on the distributor cap, as the distributors timing adjustment limitations are reached. I've gotten several different suggestions as for what could cause the issue, most prominently the possibility of the timing chain being installed incorrectly. This is a distinct possibility, as the engine was completely rebuilt but unused by a previous owner. Is this the most likely issue, or are there more common reasons for me to be experiencing this issue? Thank you in advance for the assistance, and let me know if I can provide anymore context to help this question be answered. You all are awesome!
  3. Finally got it to start after playing with the spark wires a million different ways. It starts fine and is idling at about 750, but sits comfortably at 550 with no choke before warmed up. The only issue is, my timing light is saying it's advanced 55'... I've attempted shifting the spark wires (while maintaining their order) both directions, and the car refuses to start no matter how I rotate the dizzy in any position other than that one, and it also refuses to run in the current wire configuration if I rotate the dizzy too far clockwise. It's currently turned as far the setting screw will allow counterclockwise, which seems to give the closest to "good" performance. My assumption at that point was that the handmade timing mark I've been going off of was inaccurate, so I removed the valve cover and first plug to verify where TDC really was. The timing mark, as far as I can tell, is accurate, so I'm at a loss for how to progress further. My question at this point is what would allow the timing mark to be so seemingly inaccurate, or, if it is accurate, why such an extreme timing advance seems to give me the most usable performance? I've attached linked pictures of how my plug wires are currently attached, as well as the view with the valve cover removed at what I believe to be TDC. Let me know if I can provide any more information or pictures, and thanks! http://imgur.com/M0IXuex http://imgur.com/Ro25Ly7
  4. Hey king rat, thanks for the response! The 2.8l engine had carbs on it when I got it, the same su carbs as on the 2.4l engine. The previous owner had rebuilt it, so it very well could be a modification they chose to make - I didn't even realize it was abnormal. The engine I swapped in was running heartily in the rusty car it came in before I swapped it over, so I know it's usable, assuming I didn't ruin it somehow in the swap. It's good to know that the jetting could (or should, from your explanation) be inadequate for the new engine, so I'll try tweaking that more a well.
  5. So, after the long process of an engine and transmission swap, I'm having trouble focused around the carbs and timing of my Z. Without going into too much depth, I went from the stock 2.4l engine and a stock automatic transmission, to a slightly later 2.8l with it's already connected 5 speed manual transmission from a newer, but very rusted Z. After the swap, the car started up and ran, albeit very poorly. I was able to get it across town and back to throw an exhaust on it, and upon its return, tried to tweak the fuel to air mixture on the carbs, with little luck. After a few days of the car getting worse with my misguided tampering, I decided to retrieve the carbs from the previous engine, my logic being that I knew they had worked well and were in sync, and thus would give me a better starting point. The car barely ran at all after my carb swap, and after attempting to reset the timing, failed to start at all. After swapping the thoroughly dirtied plugs out and trying to correct my timing errors, the car still refuses to start. It turns over, and will give me their occasional backfire to show its still trying, but I can't get much better than that. What steps should I take to appropriately troubleshoot what the main source of my problem is? I'm still very new to working on cars, so any severe mistakes in my process that can be pointed out to me are helpful for me going forward as well. Thanks in advance for any advice!
  6. It runs! Thank you everybody for all the help! After changing the plugs, coil, alternator, fuel pump, fuel filter, several fuel lines, and battery, it ended up being due to something in the distributor. I'm guessing it was due to a bad condenser as datsunaholic suggested, so thank you again for that! It's running quite rough at the moment, definitely needs timing and tuning, but it doesn't die any more, and I successfully journeyed down the freeway a ways and back with no threat to the RPM bottoming out upon stopping, and only one or two backfires. I pulled out the distributor from a previous 240z project, and brought over the pertronix electronic ignition kit I had it setup with as well, and it immediately resolved the issue I was battling. I couldn't have gotten this solved in such a short time frame without all of your suggestions, so you've definitely made a permanent member out of me, and I hope I can repay the assistance someday. Thank you!
  7. I didn't have as much time as usual tonight to keep tinkering with it, but I'll respond with what I know so far, and do the rest of the suggested troubleshooting tomorrow - Looks like I still get spark when it's dead, and the fuel pressure going to the carbs is a steady 4psi with the electric fuel pump I threw in today. I'll do these other suggested tests tomorrow and get back to you - thank you for the suggestions! Definitely out of sync like you're saying - I'm starting to think more and more that the issue is focused around this. I'm just not sure how it changed on me.... Either way, I either need to hunt down somebody who can get them tuned, or try my best to get the process down myself (I've had very little luck at that so far though). Are there any good resources for learning the tuning process of dual carbs for people with effectively zero experience in tuning carbs at all? I've tried reading through some step-by-steps, and they're overwhelmingly dense for somebody not aware enough of the terminology involved to picture the instructions at all. I'm still trying to figure out with screw does what on them >.< I'll do these tests tomorrow and let you know what I find! I'm pretty confident in the pump I just installed today, and up to the carbs it's reading a steady 4psi, so I'm pretty sure if it's a fuel delivery issue, it's gotta be one or both carbs having an issue (or simply being hopelessly out of sync). I'll get back to you with what I find tomorrow! Thanks again for all of the information so far - it's definitely acting a little better now that it's got a fresh fuel pump and regulator in there, but it's still not driveable. I'm hoping with the tests you've all suggested, I'll be able to hunt down the issue once and for all, but in the mean time, my primary suspect is the carbs. If anybody has any suggestions for mechanics in the Seattle area who could tune them for me, I'd love to get it done as soon as possible to either solve the issue, or rest assured that the carbs aren't causing it.
  8. It does have points, so you're probably right. I'm going to swap in the electric fuel pump I have from a previous Z, and throw in the little inline pressure gauge I have with it, so I should know by tomorrow how the fuel pressure is looking right before it hits the carbs. I'm not super familiar with what a matchbox is, but I think I just have the stock distributor on there at the moment, sorry if that's not the right response >.< I'm hoping all it is is the fuel pump, so experimenting with it tomorrow should tell me whether that's what's causing the issue or not. Fingers crossed! This could definitely be the case, but as of yet I haven't seen any rust accumulating in the fuel filter, which with my '72 Z was a huge indicator of the issue when it arose. It might be clogging up further back then the fuel filter, so I'm going to try sticking a gauge in there and seeing what it reads tomorrow with both the stock fuel pump, and a holly electric one I have sitting around (blue one, so it shouldn't overflow the carbs). I'm hoping that that will flush out whether it's an issue with the fuel getting all the way to the carbs, or some problem that's arisen with the carbs themselves. When I dealt with rust clogging the fuel line before, I solved it by washing out the gas tank with some cleaners meant for the job, and recoating the inside, so I'm hoping if that's what's causing all my issues, I can just do that again and have my car running happily =] Thank you for all the suggestions! I'll update this as soon as I've tried everything suggested so far - wish me luck!
  9. Checked spark - didn't seem super strong, so I replaced the coil with one I had lying around and had working fine before. Spark looks about the same, and nothing seemed to change. Pointing towards fuel/air then I suppose? Went ahead and replaced the fuel filter (no change), and fuel pump (made it worse... couldn't start at all, so I changed it back), so tomorrow I'm going to try an electric holley pump I had setup for a previous Z I was working on, to see if that effects the problem. Also replaced the alternator with a spare I had, still reading 14v on multimeter when running, so guess that wasn't the issue. Also, my carbs are definitely due for tuning, but that didn't change between the car running and not running. One is hissing (good, from what I understand?), and the other is not (which is bad, I'm pretty sure). I have had a terrible time trying to fully understand the dual carb tuning process up to this point, but if that somehow could have suddenly changed enough to cause this issue, I'd love suggestions for somebody with little to no carb experience (still very new to working on cars in general). Thank you again for all the information so far, I'm really hoping I can get this car acting fine soon
  10. Just went out about an hour and a half after driving it for 10 minutes then having it die while pulling back into my driveway. Starts again, but won't stay alive above a weak idle. Pumping gas seems to brighten dash lights and headlights, pointing towards power issue possibly? I did the super basic test last night of removing the positive lead from the battery once the car was started, and the car kept idling fine, until the heat, lights, and wipers were turned on, at which point it would die. Hope that provides a little more useful information!
  11. datzenmike - It does have a manual choke, and putting it all the way on seems to extend how long it's able to stay alive for a bit. DanielC - Pretty sure I'm smelling gas, so, points towards ignition then? wayno - Sometimes it gets fairly hot, but it will still refuse to start long after it's cooled down. It's also night time near Seattle, so, I think it's fairly unlikely it's vapor lock, unless it's amassing way more heat then I think would be possible in the current climate, and for as short of a time as I'm running it. It drove about a hundred miles the day before fine, so I'm inclined to think that the issue would have presented itself during that trip if it was present thisismatt - Seem to be getting a spark from what I can see, but I've got a spare coil sitting around somewhere I can try to throw in it. It's a "Flamethrower" coil if I remember correctly, and came paired with an electronic points system that I believe it's supposed to be installed with. It worked fine on my previous '72 240z. A lot of the symptoms seem to point at times to the alternator, but doing a quick test on it while running showed 14.4v... any chance it could be that still? I've got an extra alternator I could try throwing in if there's any chance that could be the issue. Thanks for all the replies so far!
  12. First off, thank you for all the answered questions I've gotten so far. I'm trying to get a '73 240z running solid enough to be my daily driver, but I've run into an issue I can't seem to solve. It's able to start, with a little help from the choke, and will idle for a seemingly infinite period of time, but as soon as it's driven around for about 10 minutes or so, it slowly loses rpm and dies, and then is unable to start for quite a while. I charged the battery, since the issue seemed to start after the battery was left to drain on accident over night, as well as tested the alternator (14.4v), checked fuel flow (seems to be consistent - stock mechanical fuel pump), replaced the battery with a brand new one, changed out the spark plugs and run over everything I can think of. It doesn't seem to get all that hot, but at this point I figure it has to be something heat related, but I have no idea where to go from this point. The car is pretty much completely stock, with '72 SU carbs, and the only thing that changed between it driving 100 miles flawlessly the day before, and being unable to run for more than a few minutes, was running some seafoam aerosol cleaner through to try and hunt down an exhaust leak (crappy non-stock exhaust from previous owner), and the battery being left running (due to somebody breaking into the car, stealing my seats, and turning the ignition to on and leaving it). Once it dies, I can try to start it all I want, and the engine turns over, but it doesn't seem to catch at all. Coming back a few hours later, it seems to start fine again. I've checked the output of the fuel pump while it was in its "can't start" mode, and it seems to be squirting out as usual, so I don't think it's related to fuel flow, and if it is, I'm not sure how it could manifest in this way. When it dies after being driven for a bit, it's usually as I bring the car to a stop, at which point the rpm lowers, can't recover, and the engine dies, unable to restart. If you have any light to shine on the issue, or any questions I can answer to help clarify, I'd hugely appreciate the input. I'm at my wit's end trying to get this car running again. Thank you in advance!
  13. I've been slowly rebuilding a project car that was left to rust, and the one portion I'm at a loss with is a part of the body and frame rail that's been eaten out under the battery. I understand from what I've read that this is a fairly common problem spot for less cared for 240's, but I would love to do what I can to get this otherwise beautiful car on the road. I'm not looking to make it perfect looking or anything initially, but I would really appreciate suggestions for how to get it patched up enough that it's not in danger of shaking itself apart on the road. I've got a couple of frame rails and the equipment to weld them in, but my concern is with the portion I need to actually weld to. The included pictures should illustrate the issue adequately, but tell me if I can take any different shots or explain the issue any more thoroughly. What would you do to make this car driveable? Thanks in advance for any suggestions, I hugely appreciate any input!
  14. Thanks for the link, I'll read through that! The choke cables are connected and operational, and if it makes any difference, the carbs are the stock 72 carbs, but the previous owner put in an l28 engine from a 280, and put the carbs on himself, so I'm not sure what to check as far as how well he did that. Putting new spark plugs in definitely help thankfully, and it starts pretty consistently now, but putting the accelerator down at all still causes quite a lot of coughing. Fuel pressure gauge is reading about 3.2 psi right before the carbs, which I've read is about what's recommended. I'm going to adjust the timing the best I can now that it actually starts and idles most of the time, and see how big of a difference that makes as well.
  15. You're right about the carbs, my mistake - got mixed up reading too many things haha. I'll keep troubleshooting the fuel and making sure everythings working. New spark plugs will hopefully make a little impact too, though the ones it came with are barely used.
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