Zed Head

Listen for the clicks first. With no sounds but the tap of that jumper wire, either grounding the injectors directly, or grounding the coil you'll hear if the injectors are even opening. I would do both tests, first ground the pins at the ECU as FW originally suggested to verify that the injectors have power and will work, then ground the coil - to see if the ECU can do the same job. A jumper wire, the key, a charged battery (don't forget that), and you'll know much more.

That's a good point on the vacuum leak. An old-timey mechanic might have the oil filler cap off to listen for noise or something, not realizing that that would be a massive vacuum leak. Everything needs to be buttoned up tight. Too bad the garage owner's not on the forum.

Sorry FW I thought that you had mentioned the "grounding the negative post" test but I couldn't find it when I looked back. It doesn't seem very sophisticated, creating sparks and ozone, but it does test a big chunk of the system, in series and connected. Seems like it should be an FSM test.

I threw the gas idea out there on the assumption that the ECU and injectors are actually working correctly. A big problem here is that nobody really knows if the garage owner knows how to test that the injectors are getting grounded or not. Since it runs on starting fluid, seems like there are two feasible possibilities - the injectors aren't opening or they are opening but they're squirting bad gas. Hard to say which is more likely. But the fact that it does run with starting fluid is significant, since it means that the plugs aren't fouled. Overall, it's still looking like the ECU is not properly grounding the injectors. There is a test that you can do that will tell pretty surely if the circuit to the ECU is correct and if the injectors are opening. Connect a jumper wire to the negative post of the coil, leaving one end free. Turn the key On. Tap the free end of the jumper to ground quickly. Every three taps the injectors should click, all six of them. With no engine cranking and no extra noise, it will be easy to hear the injectors. If you get a spark at the wire on every tap, which you should, but no noise from the injectors, then something is wrong. At least you'll be back to a focus on the ECU and the Pin 1 circuit.

These symptoms are similar to mine when I was testing a spare ECU. I got about a mile away, thew car hiccuped once, went a hundred more yards then died. Let it sit, it restarted, but then died a few more times on the way home. Ended up running home to get the original ECU which I connected with jumpers, to solve the problem and drive home. I reconnected the old ECU and it ran super-rich then died. (I think that's what happened I'd have to dig up my old thread to be sure). Eventually I replaced the two main transistors in the ECU and drove the old/bad ECU around the block and it worked. There have also been accounts in the past about poor solder connections on the ECU causing the same super-rich symptoms.

You know I kind of lost track of the problem and its symptoms since you switched threads. But, going back to Post 29, if you're getting some activity from the engine like it wants to start, I would pull a plug or two and see if they're wet or dry. Also, consider that the gas may have gone bad. If you're getting signs of life from the engine try some starting fluid. Maybe you just need to purge the bad gas from the injectors and get things flowing and moving again. Actually, I would probably just try starting fluid right now. Could also be water in the gas. Where has it been sitting?

SteveJ might have a thought (actually his Post #2 advice is the way to go!). 240Z wiring is odd to me, wires run to all sorts of different places before they get to their primary purpose. By the diagram, two wires should be connected together at the harness, a green with blue stripe (GRN/BLU) and a black with white stripe (BLK/WHT). Then a single BLK/WHTshould connect to the coil positive, along with the wire to the E12-80, which I assume is the big red one in your picture. And that seems to be what your picture shows. The diagram also shows a separate wire to the starter solenoid. So you may be right, you need a new switch. SO, as I've done before, I've distracted someone from the good initial advice - check the coil positive for voltage with the key turned to Start. You don't even need to disconnect anything, just stick the probe on coil +, and the other to ground, then turn the key. You'll probably see it jump to 12 with the key On then drop to zero at Start. Here's a link to a 71 diagram. http://www.atlanticz.ca/zclub/techtips/wiringdiagrams/240z/1971_240z.gif Thanks for letting me work on your puzzle and sorry for delaying you from the fix!

Stock coil? Still using the ballast? Check the connections to the module, and make sure the distributor is grounded well. The current to charge the coil has to pass through the module to ground, you might just have dirty connections. Forgot to say, to SteveJ's point in#4, if you just installed the distributor you may not have installed the two power wires correctly. One of those details. Is this a new problem on an old setup, or a new setup with new problems?

These are two good ideas. You're about to the point where it might be the ECU. The FSM and maybe the Guide Book will show which pins are the grounding pins for the injectors. You can ground those directly since the injector solenoids have resistance. I have made little copper probes to insert in to the ECU connector to make it easy to attach alligator clips, by smashing a piece of solid copper wire flat. With the key on, and power verified at the injector pins of the ECU connector, a quick tap to ground should cause the injector to click. That will show you that things should work if the ECU transistor does its job. If you do that a few times for each one, the engine will probably start and run for a second or two. A probe in pin 1 across your voltmeter leads - pin 1 to meter - other side to ground - should show a flicker when cranking the engine over. Or the christmas tree light should show it. I have had an ECU go bad to where the engine would not start anymore. First it flooded the engine then it just quit doing anything. So they do go bad. If you can borrow an ECU it might be worth a shot to just go directly to that. Seems like you've done enough to justify it. If you were close by, I'd loan you one.

Many people leave some of the original fluid in the tube or add some, for a variety of reasons, so it may not indicate a blown shock. The 3013 shock is gas-filled so if the seal was blown the natural state won't be full extension anymore. In other words, if you can push the shaft in to the body and it doesn't push back up, it might be time to get another. BUT, the 3013's are not easily found yet. Although you could get a 3038 in its place if you did not damage the gland nut, and the 3038 packages do seem to be available.

I mentioned the backward bearings just to illustrate a possibility. Pages 116-117 of Monroe's How to Rebuild book talks about the various ways to get them installed wrong. Matching holes, block versus cap, aligning grooves, etc. Sounds like one of those really difficult problems to solve. If you have an extra assembled short block, you could compare flow rates through the passages by filling with a funnel and watching the drain rate, while blocking passages. Or something similar, I'm not even sure where you would start. Even though you don't have signs of a spun bearing you might look for signs of heat buildup from lack of oil. Discoloration.

Maybe CO meant that both wires are connected through the resistor? Anyway, it sounds like low voltage to the ignition system, or a weak ignition module if it's electronic ignition. When you let go of the key, you get full voltage and a spark and the engine starts. I had a module that produced a weak spark and the engine would only start with starting fluid. Had to change the module. You didn't give many details mossy.

I think that this was mentioned on Hybridz but oil pressure is really a measurement of resistance to flow. The whole lubrication is designed such that the ~40-60 psi average reading is an indication of proper flow. It's a secondary indicator and can be misleading. It doesn't guarantee flow, it assumes it. Ideally, we'd have flowmeters in the dash showing that oil was actually going where it should. If you have a stock pump, correctly adjusted, and you get high pressure all the time, then that might mean there's a restriction of flow somewhere. For example, if you installed your crank bearings backwards (I think it's possible for a few) the oil flow passage would be blocked, and pressure would increase. Or if your port to the head was blocked, the same thing. And the rear seal is open to the crankcase. So really shouldn't be affected by oil pressure.

These engines are pretty durable when well-maintained. Here's one in your area. Wouldn't be surprised if it was fine inside if it was stored correctly. Some oil, a battery and a starter might tell something. Datsun 240Z Engine Complete An L28 would accept the L24 parts but you'd probably have to retune the carbs. 17% more displacement will add some power though. The EFI system is pretty easy to swap over also if you wanted make the switch. DATSUN STRONG RUNNING COMPLETE L28 MOTOR

That thing pops up every year or two. The extra cost to get all of the parts to make it work get you way up in dollars just to hear it run. If you don't the extra cash it's just expensive garage art. Search "Goerz Paeco head" on the web and you'll find threads here and there about it. The price seems to be dropping - http://www.classiczcars.com/forums/ebay-craigslist/51132-guy-asks-14-5-k-24-valve-goerz-paeco-dohc-head.html

Your diagram makes it all clear. Thanks. Should have spent some thought on it before. I've been lazy all these years. It seems so Obvious now. Virto, if the key was On when you tested the injector plugs then you really want to go directly to the EFI fusible links, the two green ones, right off the battery positive. Look at the 1978 diagram I posted above. They feed the EFI relay and the power to the dropping resistors, which CO has shown supply both sides of the injector connectors. If you have enough juice for the buzzer, there should be enough to register on your meter at the injector connectors.

I can't say myself, because I generally describe the 12 volts on each side as "transistor weirdness". Not an authority. Sounds reasonable though, I think that you're saying the 12 volts is "backfeeding" through the transistor that controls those injectors. So it should be groups of three then. Added a diagram just for ambience. Of course, it doesn't show the transistor circuits but it does show how all injectors are powered and feed back the ECU. Added another diagram. I had a 78 that had the combined EFI/Fuel Pump relay, like 1976. Just for reference. Virto will probably not need to go that deep.

CO is right, the links could be a factor. No power to the ECU. On your 78 car, there are two green fusible links in line in a small power wire directly from the positive post of the battery. If they haven't been messed with they'll be attached to the metal framework that holds all of the relays in the engine bay. Right in front of the battery. It's possible also that the links just came unplugged, they're held in place by plastic connectors that get old and break. So, overall, you have 6 fusible links. Even if the links look good, the power checks at the ECU connector will tell you if they're working. The EFI relay is also a possibility although they really don't go bad often. It's described in the Guidebook also.

I don't know if I picked the right pipe, but your dealer might have better microfiche. You can't tell if it's really available until you place an order though. I picked #56 - Datsun 280Z Cylinder Head, Rocker Cover & Thermostat L28E PIPE WATER :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com

That is a great site, thanks for sharing. I thought I knew where all of the good stuff on the internet was. I just went and pulled a 225mm flywheel from a 77 280Z in the Portland area. Couldn't pass it up, they're having a 1/2 price sale. I only went to take a look since I figured it would be more work than I wanted to do, but somebody else had already pulled the transmission (for the bellhousing apparently, the tail was still there), and the engine was tilted back with everything waiting for me. The pressure plate looked so good I got it too, it looked Nissan issue, both for $26 total. Neither needs resurfacing. Simple pleasures, collecting stuff (junk?) I don't need, easing my fear of not having a part..

The connector is under the black plastic kick panel left of the driver's feet. Three screws hold the panel. Then the connector actually has a spring clip that is pressed up (I think), allowing the top, cable, end of the connector to swing out (you have to tug on the wires, they'll be okay), far enough to pull the other end of the connector off of it's little pin pivot/hinge. Then it's free. You need to pull the top end out a ways before the bottom will release. This part might require having the door open. Once you get it free you should be able to get to the pins with your meter while inside. Might be cramped though.

AND, just realized that you didn't specify which valve. One is just a straight vacuum controlled shutoff valve, the other is the flow control valve sometimes with the capillary tube.. The shutoff valve is probably the cheaper one. ZSpecialties (aka Oliver) has a selection of parts that you might need when you're under there. 240Z, 260Z, & 280Z #'s 1,2,&3 - 75-78 280 Z=3 - AC, Heating, Dash Venting 3 - Z Specialties Online Store - If we don't have it in stock, we can get it!

Captain Obvious's solution might be an option. It will take some wrecking yard wandering. I did something similar to his, but with a valve with a 90 degree bend. If I had to redo it though, I'd locate in the engine bay like he did. There's just no room under the dash to fit the parts, let alone do the work. If you decide to try it, try to find a longer control cable along with the valve. The stock cable might not reach to the engine bay. My 76 280Z cable would have been too short. Also, almost all of the Japanese brands around his year range have some variation on the valve. Some close backwards also so you have to do some mental gymnastics about how the stock lever works. Cable retract = open. The valves are easy to get to, they're all on the firewall behind the engine. http://www.classiczcars.com/forums/interior-s30/46899-heater-water-****-valve-relocation-project.html

What is the cylinder head water tube? Cut a picture from the internet or take one with a camera, and post it.

Make sure that there is 12 volts on each pin of the injector connectors, removed from the injector, with the key On. It will seem weird from an Electricity 101 perspective, but one side is power and the other side is the transistor circuit. Probably a pull-up circuit of some kind (unresolved in other threads). Both pins in each connector will show voltage if the ECU has power and things are correct. If you have that, then check that Pin 1 has continuity (zero or almost zero resistance) to the coil negative. Make sure that the tachometer is connected. I think that the needle should at least jump when you turn the key On or crank the engine if not show a few RPM. If you can get on the forum while you're there somebody can probably walk you through some steps once you get a few results. Take a lap top, maybe there's free wi-fi nearby.