Zed Head

They're expensive and that might not be the problem. It's just a possibility. Some of us have found that any ECU from 75-78 will work on our cars. So if you find a cheap one at a wrecking yard it might be worth a shot. It could also be just a wire to your coolant temperature sensor. Or the sensor itself. If the connection gets open the ECU thinks you're in the Arctic. Working on these EFI systems is a process of understanding a collection of small systems and parts. Everything is old and could be failing. It's fun.

Might be running rich. That's how the ECU's die. Run rich, kill engine. If you have a spare ECU it would be worth a quick swap.

The stumbling and bumbling after letting it sit hot sounds like the heat soak problem. Your problem also sounds like a bad ECU. You should still watch your tachometer needle. It will tell you a lot if you look at it.

They're all very similar, changes were probably for emissions. If it doesn't have holes in it it's not a turbo cam. The turbos came out well after Nissan went to internal oiling. A cam with no holes in the lobes needs a spray bar. All of the L28's in the states are "E". Electronic fuel injection. Your main concern with installing a cam is to get good rocker arms on good cam lobes. You won't see much difference in performance between the variations but you can wipe out a cam lobe pretty easily.

I knew I should have looked at that picture closer. Standard Nissan variable reluctor distributor. So, probably the original 1975 ignition module which was the second year of electronic ignition. And maybe a "performance"coil, putting more strain on very old electronics. The module is close to the fuse box, in the cabin. It will have aluminum fins and look very cool and space age. The symptoms sound just like when my 76 ignition module went bad. Rev it up to 3500 RPM, the tach needle starts reading double engine speed, and bouncing all over. Let it die and cool off and it's okay.

Yes, it clamps or compresses the injector in to the hole in the intake. The big rubber ring is where the force is applied to the injector body. It's a loosey-goosey mechanism, not precision.

What is the Build Date? It's on the door jamb plate. I think that 75 only had one fusible link block, not two. Your car might be a 76.

Horrible! Drilling and tapping looks like the way to go. The shavings can be kept out of the intake easily, and the mount is not a super-precise fit. It's actually pretty loose, it's just a clamp for the injectors.

In case anyone missed it. It has a Pertronix under the cap, apparently. Another sign of ignition problems is the tachometer needle behavior. Watch the tach needle when the problem happens and see if it's following engine RPM or if it's acting crazy. If the engine dies and you're in gear the needle should still follow RPM as you coast down in gear. If it does you have spark, but no fuel.

You will have to run your own wires from the oil pressure switch to the relay and from the relay to the AFM plug wires. Your 77 harness only has oil pressure sender wires. The switch came out in the 1978 model year. Also, if I remember right, the oil pressure switch is normally closed (as the drawing shows). It opens when pressure is built. Your friend who knows wiring will need to know this to make the relay work correctly.

The factory AFM's have stickers with part numbers on them. The ZX and Z TB's look different. A picture or two might help identify them. If I had the car and wanted to do what you're tying to do, I would "unbridge" the AFM pins then start the engine. If it starts then dies, repeatedly, then you'll know that the pump gets power at Start. You can also disconnect the starter solenoid and turn the key to Start to see if the pump gets power. that's actually simpler, but you have to pull the correct wire. If you have Start power, then either of the two relay suggestions should work, but you'll have to learn some basic wring skills. It should be simple to do though, and cheap If you don't have Start power then you'll need to wire in another relay. Again, simple, but takes a little work..

I didn't think that Nissan used liquid sealant on the glass. Everything was preformed rubber. On the 280Z's the chrome strip fits in a groove in the preformed rubber, to help lock the rubber in place. How about a picture of the specific seal, the way that you want it to be? Not sure about what exactly the issue is...

It looks like the PO did a good job of making a variety of parts work well together. Nothing wrong with that, that's what half the people on the forum are doing. I think he just needs a way to get the fuel pump to power up only at Start and with the engine running. Like a normal 280Z. The 77 fuel pump and EFI relay might already be doing the Start function. Maybe running a relay off of the alternator charge lamp circuit could do the engine running function. Like half of the ZX system. Just brainstorming. I'd guess that he's just tired of hearing the fuel pump run when he has the key on, besides the safety issue.

Kind of looks like you're looking for affirmation of a thought. Fill the tank and see if the problem stays. These tanks are known for pinholes in the internal outlet tube. How steep is the hill, and how long is the sustenation?

It's very common for the distributor drive gear to be off one tooth. If he was able to get to the desired advance number on the damper pulley and timing tab then it doesn't really matter. That's why I asked what the number was. It's one of those things that won't hurt anything but isn't "right".

Edit - actually that would be why it's bridged. Because the 77 plug is expecting the fuel pump contacts. The easiest way to short the wires is in the AFM itself. The ZX's used the oil pump switch and two relays to control the pump. They don't have the switch in the AFM. Are you sure it's a ZX AFM? Wouldn't be a surprise of the ZX AFM is a turbo AFM. Maybe it delivers more fuel for the stroker. You'll just have to cobble somehting together if you want the pump to run differently. You're well off of the stock system.

No, somebody has been hopping up your engine. There might be other things besides the TB and AFM. The fuel pump contact might be bridged because they had low air flow at low RPM and the pump kept losing power. Might have a vacuum leak. Might have a big cam that flops the AFM vane around, causing the contact to open and close. I'd get all of the numbers that you can from the engine and try to figure out what you have. Get the head number, check the area below the casting to see if the head has been shaved. See if it's an N42 block or an F54. Might have flat tops or dished pistons. I just looked back at your first post and see "stroker". So, the PO has probably messed with a lot of things trying to get the stockish EFI to work. Might be quickest to just go to Megasquirt or Haltech or one of the other programmable EFI systems. Or carbs.

Should be 29 unless you want to have custom output axles made. https://forums.hybridz.org/topic/122244-r200-stubside-axle-spline-count-question/

GMB should pay zKars a substantial sum. If they follow up on what he found he probably saved a large percentage of their business. The valving design is common to many many other brands. It's all right there in his thread. The work has been done.

You should be able to. Study how the little arm causes the contact points to close when air pushes the vane open. Pretty easy to test, unbridge it, turn the key on, and move the vane. The pump should get power. Start power is through the relay, not the AFM. The AFM takes over when the key comes off of Start. Here are some good pictures. You might need to recalibrate the AFM if it's been messed with. http://www.atlanticz.ca/zclub/techtips/afm/index.html

Replacing the temp sensor would probably have little effect. The tweak is a cheap way to see if you are running lean, and to fix it. For whatever reason many of the old 280Z's run lean, maybe because the EFI system was tuned for 70's gasoline.

Isn't this Carl Beck's site? It's not working. @Carl Beck https://www.zhome.com/

The idle problem and the popping problem might be from different causes. But the fuel tweak might help the popping and stuttering. http://www.atlanticz.ca/zclub/techtips/tempsensorpot/index.html

What is the timing number with the distributor turned to the limit?

Engine running or not? Supposed to be 36.3, engine not running.