Zed Head
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Everything posted by Zed Head
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Those plugs don't really look that bad. All six electrodes are fairly clean and look like they've been working. #4 looks worst but still looks like it was firing. -
I used to struggle with getting the lower half of that clam shell off of the column until I realized that the trim ring on the ignition switch will pull back about 1/8 inch. The extra room allows it to slide off pretty easily. Agree with Dave that more testing would have made things more clear. Still not really clear why the "slow turn" worked, and why you saw spark, but it wouldn't start. There's only the ignition relay and the starter motor involved, unless somebody modified your wiring. Won't be surprised if the problem reappears.
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There is one last test you can run to be sure. Leave everything as you have it. But disconnect all of the wires from the negative post of the coil. Then attach one of your jumper wires to the negative post. Make sure that the other end of the jumper wire is not touching anything, and turn the key On. Take the end of the jumper wire and tap it to ground. If the coil is good you will see a spark at the spark plug on the valve cover. If something is shorted out on the coil's negative post wires it can also stop the coil from working. The circuit to ground has to be made AND broken. If you have a short it won't get broken.
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atlanticz's site (where's formerly Blue been anyway?...) has cam specs listed. That eBay cam might be an M. Or a W. Doesn't like Nissan really spec'ed a top or bottom when stamping them. Mine's an F. But, either way, the specs are not radically different. Probably the way they are mainly for emissions. It will certainly work, but you might be leaving a few horsepower behind. Might not even notice. http://atlanticz.ca/zclub/techtips/cam/index.htm
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I didn't study it too hard because all of the lines and numbers and words make my head hurt, but it seems like the info might be in the Body chapter. Might have to make some assumptions about how engineers/draftsmen think. Looks like they only show one, which might mean they're both the same. And I don't know if there's enough in there to fully answer the question. Here's a sample...
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I would use the center wire from the coil, as Chas mentioned, not a spark plug wire. You can stick a bolt in it or maybe a spark plug. Then you'll get six times as many sparks, if the coil and ignition module are okay. If you still don't get any spark, connect a small wire to the coil's negative post (Chas's suggestion again), turn the key on, and tap the other end of the wire to ground. Have the center wire of the coil, with something metallic in it, close to ground, about a spark plug gap away. You should see a small spark there and a big spark from the end of the center wire of the coil. You will be essentially acting as the ignition module, making and breaking the coil power circuit. This test will narrow it all down to the coil. As Chas said, if you don't get a spark with this test your coil is bad. When you did the test below, what you did was connect the two leads to essentially the same point. The coil negative is connected to the battery positive post, through the coil, then the positive post and the wiring. Every thing looks about right on your measurements. Do the test with the wire on the negative post. Connect the wire, let it hang in space, turn on the key, tap-spark-tap-spark-tap...is what should happen. Your injectors should click on every third tap also. It's a simple test of the ECU and wiring, in addition to the coil
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Could be bearings or bushings. People do swap in the CV axles. Take a picture underneath from the back and we can tell you what you have. There are simple things that you can do while you're waiting for the AZC package. The disconnect is in the transmission itself. Everything still spins though, just no power transmitted.
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CO, I sent it to rcb. Hopefully it works for him. I'm sure that another will show up somewhere. I'll keep my eyes open.
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Very clean. You mentioned CV's but you should have the stock u-joint half-shafts in the back. Unless he did that swap also. Worn u-joints can cause vibration, and clunking.
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EuroChas might have uncovered one problem with test method. The electrode is not grounded in the spark test video. Any part of the metal body of the plug needs to be touching a ground point. The valve cover usually woks well. If you re-run the test and find that you have spark that will narrow things down. You could also put everything back together and try starting fluid. If it starts for a few seconds then you'll know you have a fuel issue.
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No start, or no spark and no start? With the new distributor you should certainly get spark. Unless it's not turning. People have had the distributor drive shaft gear slip. You might remove the distributor cap and make sure that the rotor is spinning. (Also make sure that you installed a rotor on the new distributor. People have forgotten.).
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This part would be normal.. The + and the - have the same voltage if no current is flowing. The two things most likely to be the source of the problem are the ignition module and the pickup coils in the distributor. The pickup coils are pretty easy, check resistance, and air gap. The ignition module is a little bit harder. Might also be that something broke inside the distributor. When you check air gap, you'll see if that's the case.
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You can test the ignition system very easily, just by checking for spark. You can get a good idea of cam and ignition timing by using starting fluid to start the engine. Devise a way to test each system independently. If the engine is flooding, disconnect power to the fuel pump so it won't flood. Start the engine using starting fluid. If it runs well with starting fluid then you'll know that timing is correct, so you won't have to worry about that anymore. You're doing too many things at the same time.
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Alrighty. I didn't really get a firm impression of that. If that's the case, then a situation I had a while ago might apply. I damaged my ignition module when I forgot to put two spark plug wires on and started the engine. I shut it off right away but after that the spark was too weak to fire the gasoline. It would only start with fluid. And that was a warm engine. I know he said amazing spark, but who knows. Not sure how spark was measured either. Maybe the Start ignition wire is disconnected, and it's catching on the one spark when the key is let go, using ether. Maybe the fuel pump control is screwed up. Test that by removing the oil pressure sensor wire. The pump should run when the key is On. Then you'll know you have fuel pressure. Also, pull a spark plug after it doesn't start. See if it's wet or dry. Maybe you're flooding and the ether is enough to catch a wet spark. Finally - when you say "won't start" do you mean it tries to go but won't catch and run or you get nothing at all? Couldn't tell from cranks and cranks. Finally #2 - describe the work you did. Maybe, somehow, you've lowered the compression ratio so much that it won't fire a gas-air mixture at low RPM. Maybe you have a vacuum leak. Maybe your valves aren't closing completely (you run the risk of burning them if that's the case). Measure cylinder pressure if you can. It's a good clue. Spitballing...
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This is normal. It's an oddity of the fuel pump control system. Actually a defect, safety-wise. You said that you did a ton of work. I'm going to guess that somehow you disconnected the blue wire to Pin #1, the one from the coil, to the ECU. It's what the ECU counts to determine when to open the injectors. If you added an MSD ignition or did some other igntion or tachometer mod, the EFI system might not work properly. The tachometer is a branch off of that same circuit. Make a list of the ton and maybe somebody will see something else.
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Seems feasible. A picture of a removed bell housing would be interesting.
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Must not be much current. It will kill the battery but the circuit has enough resistance that there's not enough current for a test lamp? Seems odd. How fast does it die? Has the alternator been converted to the internally regulated type? There is a problem with some of the conversion procedures that are out there on the internet.
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"I have the fuel rail removed right now with everything else connected and I'm going to switch the key just so it starts priming, got the idea from Dave WM. " That's a good idea. Is the CSV out too? Watch all seven. There's no prime pulse on 1981 I think. That came later and even then it often doesn't work. Disconnect the starter solenoid wire, and turn the key to Start. The engine won't turn but the pump will get power.
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The injectors get power as soon as you turn the key On. So any short to ground on the wires going back to the ECU would open them. A pinched or abraded wire for example. But a short should show up in your testing at the ECU, as a voltage drop, less than battery voltage measured at the injector pins. You might also hear them click when your turn the key on although the BCDD clicks also. The CSV should only get power when the key is at Start. So it's possible that it would flood the engine, but the odds of pumping a quart of gas in to the engine through shorted injectors, by sitting with the key On, thinking, seems more likely. I filled a chevy crankcase with gasoline after I put a friend's carb on the car and tried to start it. Turns out he had got it from someone else and they had removed the float valve.
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Before you button it up, just rotate each lobe to the base circle (the part where there's no lifting force on the rcoker arm) and measure lash. No need to turn any wrenches, just get a number. That will tell you a lot. If you had excess wear you'd be able to feel it on the lobe, by running a finger nail across the lobe and feeling for a ridge. The deeper the worser. There's two easy things that will give you something to ponder over the cold weather. grannyknot mentioned rings. If you re-run your pressure measurements, but with oil in the cylinders, that will give an indication of rings versus valves. Oil tends to affect the rings sealing more than the valves.
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Might be flooding due to disconnected or broken coolant temperature sensor. And somebody parked it beside the barn for a reason. The 1980 EFI Manual is probably about the same for 1981. Might use it to at least get familiar with the parts. http://www.classiczcars.com/files/category/14-280zx/ http://www.classiczcars.com/files/category/4-manuals/ 1980 "EFI Book"
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That was my conclusion too. You can see the reverse lockout mechanism inside.
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I'll put the pictures here. More interesting. It's from a mystery 5 speed that Itook a chance on. Ended up using the case to build a 71C swap. The insides had broken synchros and the adapter plate bearing was bad. Looked like somebody got angry and tried to blow it up. But the cases were in good shape.
