Zed Head

No, I just bypassed the solenoid valve. You want to keep ported vacuum. There should be a T off of the ported vacuum source. One hose goes to the vacuum canister and the other goes to the solenoid valve, which then passes through to the diaphragm. Run that one straight to the diaphragm. Another way to do it is to just unplug the wire to the solenoid. It is normally off. The transmission switch supplies power in gears 1 - 3, to close the valve. That is probably the easiest way to do it if you're not sure you want to run that way and want to try it first. Be aware that you'll have a dangling wire that is occasionally hot, although it does have an insulated end. Same thing at the transmission, you could disconnect that wire (anyone who does a 5 speed swap on a 75 or 76 probably has that switched hot wire dangling under the car). There is a good diagram and explanation on page EC-9 in the FSM. It doesn't show the three way vacuum hose T though. Check it out then stare at your engine for a while and follow the hoses and wires.

Home Depot? What year car? This forum and others have pretty busy classified sections.

Z Tyler Z, I forgot one important thing about the 1976 model, that probably hurts gas mileage. The 1976 model has a switch in the transmission that controls a solenoid valve that opens the vacuum advance line to the distributor. If everything is connected properly, you only get vacuum advance in 4th gear. It's described in the Emissions section of the FSM, so I'm guessing that retarded timing gives the government mandated mixture of combustion byproducts. It's only described in the 75 and 76 FSMs. I bypassed my switch (just ran the hose directly to the vacuum diaphragm) so I have vacuum advance in all gears.

Reply to this old slightly off-topic post - The compression values can vary a LOT depending on which gauge you use and with what adapters, etc. I bought a screw-in type gauge recently and got 120 psi with the adapter tube and 180 without it. The volume of the gauge hoses, adapter tubes and the gauge itself become, in essence, part of the combustion chamber volume when the test is done. As I've read many times on these forums, it's the comparison between cylinders that matters the most. Back to the point of your question, in my case, my odometer says 46,000. Could be 146,000 or 246,000. But I got five 180s and a 179. I was surprised, especially considering that my engine burns a little oil and shows some signs of a hard life.

This picture tells the story. From the 1978 wiring diagram.

I honestly don't know if the PO was smart enough to diagnose it. I can tell you that the fuel pump safety switch on the AFM module is not operational or wired in on the 78. There are no pins in the harness for it. That would be the only way I could think of that the fuel pump wouldn't run in the key "on" position since the fuel pump has to run in the on while the car is running. The '78s used an oil pressure switch to run the fuel pump when the key is at On.

Browse through these forums for a little while and you'll get a picture of what you're in for. 280Z EFI is not like 240Z carbs at all. ECU, relays, fuel pump, AFM, injectors all have to work correctly for the engine to run. If the car has sat for a while, you'll probably be in to clutch, brakes and electrical (lights, etc.) also. Just spend a few minutes reading the threads about 280Zs that won't start or stay running. It's fun but it will probably take some time (and money)..

Maybe some are leaving off the reinforcement plate that comes with the Energy Suspension mount? That would raise the diff nose up a small amount.

Coincidentally, just saw this on Hybridz from a guy who had an ECU that wasn't firing the injectors. Said he had his coil wired backwards. Post #72. Also said his fuel pump wouldn't run because he had a bad EFI relay. http://forums.hybridz.org/index.php/topic/91070-moderns30s-1972-datsun-240z/page__pid__904721__st__60#entry904721

Cozye, just noticed your post. The fuel pump only runs when the motor is running (opening the Air Flow Meter flapper valve) or when the key is at Start. When the key is at On, you can make the fuel pump run, on 75, 76 and 77 cars, by opening the AFM flapper, which makes the contact for the fuel pump. Otherwise the fuel pump should not run when the key is at On. This stuff is addictive. Good luck Funky-P (I hope that's like a Married with Children ref or something and not an attribute...).

Darn! I wrote a nice long post and this thing timed out on me. Hit Go Advanced and everything is gone. Any way for the admins to add a little time to that function? Do I set that somewhere? SBlake, I thought about that, and I have read the same, but I have measured mine according to the procedure and the wires going to the injector all measured line voltage (12.6 V). I think that dropping resistors actually drop current. This is what the manual states - "The dropping resistor is provided to drop electric current flowing through the injector and control unit." (Edit - Not sure of my reasoning so removed it. Tests still worth doing) (2nd Edit - My reasoning was wrong. Apparently both voltage and current drop when the injector is fired. Apparently to nine volts. But at zero current flow, voltage measured is line voltage.) Funky-P, my comments are from the 1976 FSM. Your 1977 might have a different pinout but the test is still worth doing. If you have power, then you can focus on why the ECU doesn't fire.

What is the "lamp to injector harness method". A test light in series with an injector? Watching for flashes? I think the injectors should have twelve volts to them at all times. Testing is described on page EF-23. They fire when current flows and activates the solenoid. Current flows when the ECU grounds the circuit. That is my current understanding of how the EFI works. I could be wrong.

Here are a couple of links from Hybridz on the topic. Make sure you read the whole thread in both, there is some misinformation in the beginning posts. [Edit - no offense to JMortensen (one of the posters in the other threads). Apparently there had been some funky information floating around in general at the time (over 7 years ago).] http://forums.hybridz.org/index.php/topic/19920-r200-seals/ http://forums.hybridz.org/index.php/topic/17356-370-lsd/page__p__126272__hl__%2Bpinion+%2Bflange+%2Bcrush__fromsearch__1#entry126272

Clutch and slave cylinders are good novice projects. Your master cylinder and reservoir are in front of the clutch pedal on the other side of the firewall. Picture with arrow attached. Your slave cylinder is bolted to the side of the transmission on the passenger side. If you look down between the battery and the starter (second picture), and back to the transmission you can see it from above. There is a flexible hose attached to it which holds the hydraulic fluid. Brake fluid is the hydraulic fluid used to fill the reservoir. This is an EFI engine so will look different than yours but the parts are in the same general spot on all Zs. Careful with the brake fluid, it will eat your paint if you spill any.

Howdy MEZZZ, I was just searching the site for some feedback on the effects of using urethane inner bushings on the rear control arms (transverse links) and this thread popped up. I've been changing bushings one system at a time and don't know if I want to do the inner bushings or not, since my rubber ones are still in pretty good shape. How did your mod to the R/T mount turn out? How is the gear noise and how is the ride with urethane bushings all around?

12 volts to the coil and the tachometer hooked up? I am not very good with wiring but I think that the tachometer is part of the ignition circuit, the ground from the coil runs through it to the ignition relay (Page BE-33 in the 1976 FSM [i don't have the page in the 1975 manual]). Just a possibility, if you're trying to start the car but you have the insides torn up. I tried to start mine once with the tach out and broke a sweat for about 5 seconds until I remembered reading about it.

The rubber plug is actually pretty deep, about 3/8 to 1/2" I would guess. And mine fits flush so the screw must be in pretty far. I can't see the head of the screw. But my AFM is a rebuilt one from MSA (or wherever they source theirs from) so I don't know if it was ever properly adjusted. Apparently the stock AFMs are factory-adjusted. But I did end up screwing mine in even farther and the engine idles fine, and accelerates smoothly. I have rethought my original comment about no effect anywhere but idle and I think now that there must be some effect just off idle until enough air is flowing to offset it. One more thing to play with...

The other way to richen the mixture at idle but with little effect anywhere else is by the idle air bypass screw (it might be called the lean adjustment screw or something similar) on the AFM. Turn it in to richen, then adjust the idle speed with the throttle body screw. It's behind the rubber plug on the bottom, side of the AFM. I have a 76 and I had to adjust mine to keep the flapper off of the fuel pump contacts. Haven't been emission tested since then so I don't know where it will come in.

There are few people down here in Oregon parting out lots of Zs on Craigslist. Two of them have been doing it for quite a while, and there's a new guy (new to me in my short Z life) down around Albany advertising a whole warehouse full of Z parts (including fuel tanks), and a guy in Colton (east of Woodburn) that says he's parting out 12 Z cars. Just search 280Z on the Portland Craigslist - http://portland.craigslist.org/

Stopping from reverse.

Sorry Sledge, I gave you bad advice, about the tach (although the jumpy tach is odd). I misread your post or got it confused with someone else's or I didn't read the whole thing. My advice was for a car that cranks but won't fire. I missed the comments about it starting then dying. If it ran before and you didn't move the distributor and you're getting spark then it is probably fuel delivery or injector firing issues. Unless you changed something while you were fixing. Did you move any plug wires or take the distributor off or loosen the distributor adjustment screw? Are you trying to start it with everything, all wires, hoses, etc., attached properly? You can't leave stuff off like you could on a carbed engine, then put it back together after it's running. Everything, including the oil filler cap and the dipstick, has to be on the engine, properly attached. If you can, check your fuel pressure. I agree with Idaho, your original description sounds like a fuel delivery problem. Running then slowly dying shows that you might be running out of fuel at the injectors.

Make sure the lifting pad is centered and/or not too big or you'll crush your exhaust pipe.

Where do the other ends of the wires go? Should be easy to see if you have the distributor out. The location on the thermostat housing will tell you which switch or sensor it is. And from the picture you posted, one of the wires looks green.

Slow day, I'll take a shot. The output from the negative side of the coil has to go to the tach and the ECU so the ECU will know how fast the engine is rotating to feed it the proper amount of fuel. Maybe you lost that connection. I have not actually followed it out, but I do know that if you disconnect your tachometer your engine will not start or run. Does your tach work when you try to start the engine?

Ah. You mean the 4th gear vacuum advance switch. Sorry for the misunderstanding. That is an Emissions device that gives vacuum advance only in 4th gear. Kind of a weird thing. I disconnected mine from the switch and ran the hose directly to ported vacuum (basically just connected the two ends at the solenoid switch). If you reconnected the electrical wires and all of the hoses then you will be running with no vacuum advance in gears 1 - 3. If the PO, for whatever reason, had connected your advance hose to a full time vacuum source, and set the timing that way, you will now have retarded timing, since the hose should be on ported vacuum. That would cause your idle to drop. Just a possibility. It might be worth rechecking your timing with a light. It's raining in Portland (where you're at too I see) so I'm spending too much time here. Tell me to stop if I'm overdoing it.