Zed Head

That last video was informative. Did you "prime" the fuel system like you describe above or just try it with zero fuel pressure? That would make a difference. You're getting closer. Working on these EFI systems is best done by being rigorous, detailed, and repeatable. For example, my question about fuel pressure. Can't tell if the latest video is different from the other ones. Another thing to look at is the TVS (aka TPS). It's the switch on the throttle body that tells the ECU the engine is at idle, so it can add a little fuel. And are you starting with your foot off the gas pedal or are you pressing it? These engines start best with no pressure on the pedal. When the AAR is working correctly. Also, the fact that you can run the fuel pump with the key alone (which you never explained, above) could indicate a wring issue. Maybe your ACC circuit is enabled at Start and the voltage drop is weakening the spark. Could be that the ballast resistor is incorrectly wired, with Start passing through the resistor. Weak spark plus lean mixture = hard starting. Lots of little things to look at, but any one or combination could be a contributor. You didn't get the quick fix so it's time to open up the Engine Fuel chapter and start testing components. Make a list of what's not right and post it (like the fuel pressure issue and the way power is supplied) and somebody might see something. Here's a sample of what you'll find in the FSM.

It's early. I would put more in to your description of "difficult starting". Do you mean that you have to try two times? Or that it idles poorly for 1/2 second? The sputters, before it dies? Because really, it seems to start pretty quickly. How does it start when it's warmed up? Is this only a cold start problem? The more details on the actual problem, the better. If you want to mimic what the AAR would do, open the idle screw up so that when it starts the RPM sit at 1200 RPM, engine cold. You can do this in one shot, the engine won't heat up that fast. Start it, adjust the idle screw, turn it off, restart. See if it starts the way it used to. If it starts fine, but the idle never drops, then it's not a starting issue, it's an AAR issue.

I looked in the FSM and see what you did in your picture and where your hose ends are. Sorry, I couldn't tell what you were doing. My mistake. Haven't looked at AAR connections for a while. All that "bypass" will do is confirm that your AAR was never opening or closing, Not moving at all. All you've done is open the passage permanently. You'll be stuck with an idle that's too low, then gets right, or just right then gets too high. Best to fix the AAR. Sorry for the mess of posts.

Did that hose nipple on the big hose have a plug on it or was it open to air? It should be plugged, I believe. Anyway, I think that your problem is a simple one, don't do anything crazy like adjust the AFM or change timing or what you showed in that picture.

Numbered my edits 3. Actually, I'm not sure what will happen with that setup. Looks like the AAR is directly to air. You'll get a lot of unfiltered air if it's open, might get the high RPM. Or you'll get nothing if it's closed. The loop on the throttle body to the big hose probably has no affect. 2. Moved to front!~ - BUT. Your picture shows that you completely bypassed the throttle blade. The engine might go to sky-high RPM right away. Don't start it like that. 1. Aacck... The AAR can't be bypassed without having the idle speed problems. All cars, even carb'ed cars, have devices to increase idle speed for a minute or two until the combustion chambers get warm enough to work right. Your idle speed with the bypass can either be set to have a very low idle RPM that needs throttle pedal action to stay running, or it can be set with a good cold idle that gets too high after it warms up. If nothing changes though, you'll know the AAR wasn't working.

IF we redefine your issue from "difficulty starting" to "low idle after starting" or "high idle after short warmup" then the problem is most likely the AAR. IT's supposed to be almost completely open at normal cold engine temperatures, like anywhere from 30 - 90 degrees F, then close slowly as it warms up. It actually has an electric heater inside to make sure it closes within a short amount of time. I would pull the hose from the AAR and see where it's at engine cold. If it's closed already, you have a problem. They can be adjusted. Maybe someone messed with yours already.

In the video the RPM went to 1000 after it started and it didn't sound too bad. Doesn't fit your description. It does sound like you might have a starter problem though. It seems to be letting go before the engine starts. Oddly, a 1978 parts car that I had would do the same thing. You had to keep trying until it would catch. The RPM increase with a small vacuum leak is normal. Your fuel pressure readings seem low but it's not clear what you're doing. I don't know why the pump would get power just from turning the key ON/OFF. The pump shouldn't run unless you hit Start, or the engine is actually running. Get the engine running, and take the hose off of the FPR again. Then read the fuel pressure. That will tell you about your fuel pump and FRP. Or take off the small wire from the starter solenoid and turn the key to Start. That will run the pump, but not the starter. One last thing - you said that you confirmed that the AAR flap was moving freely but you didn't say that it was open when cold, and closed when the engine is warmed up. If it doesn't move, then there's no idle speed increase when cold. Basically, it's not doing anything. You can apply 12 volts directly to the two pins if you want to verify it's closing. It only takes about a minute.

You have your "heats" a little blended together and mixed up. Engine heat will show up on your Temperature gauge. If that's correct, then no need for bleeding, or looking for blockages that could cause overheating. The cabin heater just takes a small amount of coolant fromthe back of the head, runs it through a small radiator in the cabin, then sends it back to the water pump. But, as FastWoman said, it's probably your "vacuum **** (rooster)". Here's a link with diagrams and complete explanations of the AC system. My 76 would bust a hose every few months until I patched together some new flexible hose on the ends of the old brittle hose. AC chapter. 76 or 78 is probably the same, if you can't download the complete giant 77 FSM. Start in the engine bay, it's easier than behind the control panel. http://www.nicoclub.com/FSM/280z/

I suggested the gland nut torque just so that you could see the final nail in the coffin. But, if the rest of the tube is in okay shape, the base and the casting could be used for some of the "coilover" kits being sold. So don't throw it away, sell it. Trade it maybe.

That sounds more like a clutch issue. It's not disengaging completely. If you're lucky it just needs adjustment at the pedal. If you're not lucky, one of the hydraulic cylinders is going bad. Start a new thread about the problem. The RTz diff mount just stops the clunking noise that can happen with a loose stock mount.

Don't forget what happened to rossiz's head from Al. California Datsun and Datsun Parts LLC are the same company. Triple check all work before using it. If the head has been laying around, odds are it was built before the lash pad problems were solved (if they have been).

You should start your own, new, thread. This is bartsscooterservices's build thread. Click "Start New Topic" on the right... http://www.classiczcars.com/forum/63-introductions-and-rides/ http://www.classiczcars.com/forum/61-open-s30-z-discussions/

Thanks for the confirmation. I already picked up a dual action (NC and NO) Siemens/BMW relay with base, at the wrecking yard. Purple. 100 ohms across the solenoid. Since then I wondered if the fuel pump control relay could have been used instead. It seems to be the only NC relay in the 1978 car. Only wondered because I have one. Did you look at that picture in #31? That's the worry. Maybe the water it was submerged in was cold and oxygen-free, and that's why it still works.

When you tighten the gland nut on to the shock body those threads and the strut tube are under tension. In use, the tensile force doesn't change much because the shock shaft just moves up and down inside the assembly. Torquing a shock in to the tube will tell the story. It will probably spread apart and you won't be able to torque it down.

Lowering my 76 ~1.5" had a major affect on handling. Much improved. And a differential mount of the RTz design made the overall gear-shifting operation much more solid and pleasant.

If I read this diagram right, two of the pins on the BWLCR aren't even used and a simple normally closed relay could replace it. Looks it might even be a two way relay, maybe the same one is used in 78, just wired NO instead of NC. I'd take it out and look but seat removal is required, and we'll be up in the 80's today. A common Bosch relay. I can get my current draw back down and cool things off. Might keep the old rusty one there though, just for the history.

I've spent all of these years avoiding the assemblage of odd things that were used to generate electricity and now you've dumped me right back in to it. Rust, corrosion, over-voltage... My bliss is gone. Thanks a lot! I wonder how my fuel pump relay is doing since it's been supplying a pump and an over-voltaged check relay. Might as well rewire the whole car.

classiczcars people! jalexquijano has resurrected this thread, from dead. The last post was October 2012 before he began resuscitation. ~2.75 years ago.

I think that's normal relay pull isn't it. The EFI and fuel pump relay pull the same? Here's a picture. At the time, I was in "just make it work" mode so didn't even look inside the relay. I'd forgotten how bad it looked. Definitely on the fix list now. I think that the electrical tape is there to hold my fuel pump power circuit tap line in place. After I had the car a little while and started parking it outside I found that it had a pretty serious leak through the windshield seal. It probably sat outside and filled with water before I got it. Had a hole under the driver's seat also.

MSA is known for packaging problems, and not caring about it. Only game in town, too bad. I started a thread for MSA. Linked this thread. Hope you don't mind, let me know and I can edit it out.

You need to either remove the vacuum hose from the bottom of the regulator, or measure the pressure without the engine running by removing the yellow wire from the starter solenoid and turning the key to Start. The purpose of the vacuum hose is to maintain a constant fuel pressure from one side of the manifold to the other. So if pressure inside the manifold increases (vaucum drops), pressure inside the fuel system increases. You can also convert inches of vacuum to pressure. 17" = 8.3 psi. 28 + 8.3 = 36.3 psi. Looks good.

Somebody posted about it on Hybridz also but they moved it to their Tool Shed for some reason. Had some more details. Looks like the old "wire me the money and I'll have the car shipped scam". I felt the draw of one of those way back when I was first looking. Low price, need to sell", in the military (lends respectability), can't communicate directly, etc. All of the signs. http://forums.hybridz.org/topic/123073-scammers-on-z-cara-now/#entry1150782

28 is normal for a running engine. There's a hose from the intake manifold to the FPR that adjusts pressure based on manifold vacuum level. Irrelevant to the leak-down but important to know for future work. It does look like your FPR leaks down. The valve in the FPR is just two pieces of steel that press together. A little bit of rust could cause a leak. If "recently" is three years ago, that might be what happened. No recommendations. I've had luck with the factory FPR's and have since installed a modified Bosch regulator. I'd get one from a local store that will take returns. Swap until you find a good one.

I ran a new fused wire to the fuel pump power supply, at the harness junction next to the passenger seat. So the relay gets powered with the fuel pump. The relay seemed to be the typical Nissan relay, I think I measured 0.3 amps draw while I was trying to figure out what was draining my battery. More worrisome for me is the fact that high water mark under the passenger seat was about halfway up the relay body. Pretty sure it's been wet. That should really be one of my winter projects. The relay, the parallel L circuit, and cleaning up the wire ends that are still poking out of the harness from where I cut off the regulator plug. They're insulated but hanging in space. Mementos of my first modification.

Are you planning a complete restoration and want to get the period (actually VIN range) head on it? A poll of VIN numbers and head ID's might tell the story. If you're doing a restore you might be removing the right head and installing the wrong one. If you're not doing a restore, why replace it?