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NewZed

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Everything posted by NewZed

  1. NewZed
    I don't think that you can say this with certainty.
  2. NewZed
    Just curious, but many people have mentioned looking at your diagnostic data. Is there some reason that you're not? You're obviously able to change the settings, you changed the injector values. If you look deeper you might find something. So far it's just been guessing about a clicking noise. If the injectors are dumping fuel you'd smell in the exhaust and see it on the plugs. Are you seeing signs of running rich or assuming that it's rich. I remember on my 76 when the idle got too low the fuel pump relay would cut fuel and the engine would stumble until I hit the throttle to raise idle speed. In the cabin you'd hear a bunch of clicking noises. Maybe the clicking noise is a relay or two and not the injectors. Keep looking. Good luck.
  3. NewZed
    How about the pickup tube? Could be clogged or maybe it even fell off? If you took the filter off and nothing came out, you're pretty much at the first place to look after the pump. I don't think that system is complicated. Don't know. Good luck.
  4. NewZed
    You might put a mechanical gauge on the pressure sender port to be sure about what you think is happening. Or just remove the pressure sensor from the block and crank the engine over. If you're right, no oil will come out. If you're wrong, there will be a mess. Just a simple test to be sure you're on the right track. Also, are you sure that your drill motor is turning the correct way? Counterclockwise would be reverse on a drill motor.
  5. NewZed
    There are too many pages and I haven't been following, but does your EFI system have any feedback or measurement tools? A "dashboard"? You might be able to pull up injector open duration and see if it's out of whack. That could be an input signal problem. If you have an oscilloscope you could probably measure actual injector open time and compare with the ECU's programmed duration and look for mismatches. Stuff like that. Just spit balling. I'd check your EFI system capabilities though, some of them are pretty sophisticated.
  6. NewZed
    Good luck. Beware the vague terms like burnt or overpowered. With electricity there are two very basic things - breakdown voltage and over heating. Breakdown voltage is when the electricity just "blows through" the insulation, due to voltage over the limits of the insulation, to short circuit to ground, or to the next wire over in an injector. Overheating is what happens when too much current passes through a conductor and creates more heat than can be dissipated over time, which can also damage insulation. With injectors the insulation between the windings is the same for low or high impedance. They both use 12 volts. Peak and hold "peaks" at 12 volts then drops to a lower voltage to hold at a lower current. It doesn't start at a lower voltage. The biggest beware is to know that many of us are just Googling, or guessing. Injectors are pretty durable devices. The odds are very low that your EFI system damaged them. The injector companies will gladly sell you a new set while you try to figure out the true source of the problem. A meter is your best friend. You don't have to be an expert to measure the basic stuff.
  7. NewZed
    But the system would send less current if you had them set to low ohms. Your high ohm injectors can't be overpowered by any of the injector settings. If you had set low ohm injectors to high ohm, maybe. You could pull the connectors and measure resistance with your meter.
  8. NewZed
    The injectors are cooled by fuel. Seems more likely that the injector control transistors would get damaged. But if they are high ohm injectors then they should be more safe if you set them to low ohm. Besides that the power pulse is very short. I don't really think that you can damage injectors with an incorrect impedance setting. Your transistors are probably fine too, they don't see much current. Your problem is probably something else, I'd guess.
  9. NewZed
    You should always get full weight on the suspension and roll the car back and forth before evaluating changes. Make sure the shocks aren't binding by moving the car up and down. And consider tire size, a smaller tire will lower the car but make the gap bigger in the arch. Best to measure from the rocker panel to the ground if you're talking about lowering. Don't blend lowering with tire gap. And drive over a few speed bumps slowly early on so you'll know what's going to scrape later.
  10. NewZed
    What's going on with your advance mechanisms? Do you have vacuum advance connected? Does the breaker plate move freely, or is it slow and sticky? Seems like it was running well then the timing changed and it died and kicked back. If vac advance is connected you might disconnect it and try again. Turn the distributor a bit one way, then a bit the other way if you don't have a light. You're pretty close. I wouldn't worry about the tach right now, the way it ran at the end seems like it has good spark.
  11. NewZed
    The low RPM driveability problem is super common. Might be that /Nissan tuned the system to the edge for emissions on 1970's gas and it's too lean on today's gas. This fuel tweak really works.
  12. NewZed
    Use more words! "Off" which way, loose or tight? "Rough" how? I mentioned the stumbling and bucking. Pretty typical to work your way up to good-running, through many small improvements. They're easy to get running but take some work to get to perfect.
  13. NewZed
    They all go at the same time. Another thing to watch is the tachometer needle. If it moves smoothly with RPM that's good. If it jumps around for no reason or reads the wrong RPM, that's a sign of ignition module failure. The ECU's also go bad, usually running rich and rough, until they just die sompletely. Have you tried to drive it yet? These old AFM's are also known for running lean. If that's the issue the engine will pop back through the intake and buck and jerk when you give it light throttle, under load. http://www.atlanticz.ca/zclub/techtips/tempsensorpot/index.html
  14. NewZed
    Burnt/bent/sticky valve maybe. Have you done cylinder pressure measurements? Should be at most 185 psi, depending on the gauge used. Maybe the PO shaved the head. Looks like you're doing everything right, for an engine with good working parts. There a couple of odd things though, I quoted above. 1978 used the N47 head. Why does yours have an N42 head? And what type of coil are you using, in detail. The ballast resistor is actually a device that changes resistance as ignition dwell changes. It's not just a resistor. It's not a well-understood device, but pretty ingenious. You might be overpowering the old 1976 ignition module. Zhoob's thought that you might just have spark crossfire seems to fit. Maybe you just have bad plug wires. Move them around while the engine is running and see if things change. Use an insulated screwdriver or wooden stick., or make sure your hands are dry. But here's some more possibilities. - The PO left the PCV port under the intake manifold open, either at the manifold, or at the side of the block. You missed a vacuum leak with your testing. - The PO connected your vacuum advance to "always on'; vacuum instead of ported vacuum. Check your timing at idle and disconnect the vacuum advance hose to see if it stays the same, It should. - The weights on your distributor mechanical advance have lost their springs and your timing is jumping around. Again, check your timing and see if it advances with RPM like it should. - the breaker plate in your distributor is gummed up and getting stuck at high advance. Timing light should tell you what's going on in there.
  15. NewZed
    Sometimes that is caused by a flattened cam lobe. The exhaust valve doesn't open all the way. You might recheck your valve lash, examine the cam lobe quality, and also check your camshaft timing using the notch and groove. Cam lobes have been known to go flat very quickly. "After adjustment" is good. Make sure the drivers side of the chain is tight and the timing mark is on zero. Use the cam shaft bolt to turn the engine.
  16. NewZed
    Wouldn't the ECU need a MAP sensor for vacuum advance of timing? Also, an RPM signal for centripetal advance. Does the 2J use a crank mounted sensor or does it use the distributor type CAS? Interesting idea. Might be easier to just modify a distributor that has vacuum and mechanical advance to work in the engine, to trigger an electronic ignition. Timing control is the hard part.
  17. NewZed
    Your best option is to study the wiring diagram. That's why they were created. Read the FSM Engine Fuel chapter also, it explains the fundamentals of how an EFI system works. That will help you. The EFI harness is separate from the main harness for the most part. The gauges might take some work if the sensors are different between Nissan and Toyota. Getting the fuel pump control system to work will be difficult, probably. It's described in the FSM also. Using the Cressida EFI system in a Z or ZX is not common. You're kind of on your own.
  18. NewZed
    What did you do to get it to fire? Are you saying that you had a bad ground?
  19. NewZed
    CZCC.com has wiring diagrams and FSM's The FSM chapters typically have a smaller diagram specific to each area. I'd look through those. https://www.classiczcars.com/files/ Of course, you can also examine the wires at your shift linkage and the switches on your transmission. Here's a site I like to use to see which parts go where. Look under Powertrain and/or Electrical. http://www.carpartsmanual.com/datsun/Z-1969-1978
  20. NewZed
    Tach input is the CAS signal. Tachometer is just a meter that measures engine speed, which is what the CAS does. You didn't confirm power to the coils yet. You have to have power to the coils. Power AT the coils is not provided by the Megasquirt system. Megasquirt provides and controls the grounding of the power. Look down at the bottom of this picture where I scribbled. https://www.msextra.com/doc/general/ms2external.html
  21. NewZed
    Coil power typically comes through a fused switched circuit. The Megasquirt system grounds the circuit to control the spark but the power to the coils can come from anywhere. You might browse some of the wiring diagrams on the DIYAutotune site or see what you can find on Hybridz to see how people power their COP systems. I haven't used one so don't know if there is central point from which the coil leads split or if each one has its own circuit. Follow your COP wires back and see what's missing. I did a Google and found a few things. The first one uses the same words I did, so I might be on to something. There's probably a wire from your harness that you need to connect to switched power. http://www.megamanual.com/seq/coils.htm
  22. NewZed
    Sorry, but you're going to have to dig in a little deeper. You didn't watch the video I linked, it shows how the three wire CAS works, You didn't answer the implied question about the Megasquirt software and whether or not it shows the CAS signal. Do you have Tunerstudio, or other tuning software? There's a bunch on the site about CAS signal problems. Since it worked at the supplier's shop the problem would seem to be with your equipment. The CAS signal is most likely. Here's one that covers a few things. https://www.diyautotune.com/support/downloads/ http://www.tunerstudio.com/index.php/tuner-studio/tunerstudioms-menu
  23. NewZed
    I'd try to know more about these unknowns. You can waste a lot of time otherwise. You said that you have LS2 COP so there are no coil packs. There are two reasons a coil won't discharge - no power or no making and breaking the power circuit. You can probably check for power with a meter at a coil. The CAS can usually be tested also. Here's a typical video, it's actually pretty good. I don't see any reference to checks with a meter in your post. That's the place to start. Or, if I recall correctly, Megasquirt itself will confirm some of these things. Doesn't your "dashboard" show the CAS signal? Kind of looks like you just plugged things in and turned the key. https://www.youtube.com/watch?v=RvuzZJqQDf4
  24. NewZed
    I hope I'm not leading you down a messy path. This module swap is fairly easy if you have electrical experience, but might be a bit tough if you don't. It is a very common ignition module swap it works on many different brands of car and motorcycle. If you want to do some more searching and reading, use "GM HEI module swap" on the Google. I assume that this is for your 79 280ZX? If so, it should work fine, using just one of the pickups, using just two of those three wires. You can just leave the other one disconnected (tape up the end to avoid shorting the other pickup). The "black box" is a GM HEI module, that you can buy from any auto parts store. Ask for a 1977 Camaro ignition module. It has two holes in it for mounting inside a GM distributor but you'll be using those holes to mount it close to your coil and distributor. The mounting screws need a good ground circuit, so don't mount it to plastic or rubber, find a good solid metal spot for it. https://www.rockauto.com/en/catalog/chevrolet,1977,camaro,5.0l+305cid+v8,1035111,ignition,ignition+control+module+(icm),7172
  25. NewZed
    Don't know if you meant propeller shaft or halfshaft (drive shaft), but you can still get the "D" bolts for the propeller shaft, apparently. http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/propeller-shaft/2 https://www.nissanpartsdeal.com/parts/nissan-bolt~01111-00051.html
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