Zed Head

Here's a followup to my last post. I still have the hot start problem, even with an FPR that holds pressure over time. It seems to be holding close to full pressure also, because the engine starts right up over night and after sitting a few days, just like a modern car. But even with a rail full of fuel, if I get the engine nice and warn, then let it sit for about 20 - 30 minutes, I get a nasty thirty seconds to one minute of stumbling, low idle poor running. I'm wondering now if the problem might be an overheated solenoid, sticking and causing the injector to stay closed. Just another way to get to a lean condition, which is what my hot start problem is like. It seems to be isolated to one or two cylinders, based on the way it runs. Just wanted to followup. On the plus side, a system that holds pressure is nice for restarting in general.

You'll save yourself a lot of time, money and aggravation, in both the short and long run, if you download the Factory Service Manual, and read the Engine Fuel chapter, and do some testing. It's free - http://www.xenons30.com/reference.html If "bit" means "not" then it's unlimely the dropping resistors are bad because they have nothing to do with power to the fuel pump. Blown fusible links or bad connections are a more limely cause. Good luck.

They don't really do much work besides convert a small amount of electricity to heat. I don't think that they go bad very often. Have you measured resistance and continuity? The test is described in the FSM Engine Fuel chapter.

You didn't provide the details or reason for your swap, but I had a problem with my tach after modifying the ignition system and found that an extra condenser/capacitor on the coil negative post fixed the problem. But my tach needle would just bounce and jitter at zero, it's not clear in your case what you mean by "not work". I swapped all of the 76 parts out though, so this might not help your situation. You do know that the 76 coil is a low current coil and uses a ballast resistor to drop the voltage when running, but the 81 coil has no ballast resistor and uses the full 12 volts and full current. Did you do any other modifications or just swap the coil? Edit - just saw the part about the 81 ZX distributor. So you're using the E12-80 module? Did you disconnect the 76 ignition module by the fuse box? It's not necessary any more. Maybe it's interfering. You can just disconnect each wire and cover them up to avoid shorts, since some of them are hot when the key is on.

Whoops. Here it is - http://courtesyparts.com/ Don't try to put you vehicle description into the Search box, just put the part number in the box on the right. I have ordered directly from the web site, but you can call them too. Good luck.

This mighthelp you out - http://www.carpartsmanual.com/datsunS30/DatsunZIndex/PowerTrain/TransmissionGears/4Speed/tabid/1707/Default.aspx Find your part number, then go here - http://www.carpartsmanual.com/datsunS30/DatsunZIndex/PowerTrain/TransmissionGears/4Speed/tabid/1707/Default.aspx and put the part number in the search box. The one I picked actually shows as available but I don't think you'll know for sure until you call or order it. Notice also that there are two 1971 4 speeds. If you have a post august 71 4 speed, it looks like any 4 speed after that might have a gear set that would swap in, based on the "superceded" comments. Probably cheaper to get a later model 4 or 5 speed and swap.

It could also be the brake pressure differential switch, either stuck or indicating low pressure in one half of the brake system. How do the brakes work on the car? Does the light go off if you pump the brakes?

Are you sure that you unplugged the right relay? Since you have the AFM switch, and the one wire oil pressure sender, the relay should be a 1x1x2" silver box, with two connectors and 11 pins.

I can't decipher your train-of-thought-dump-to-paper writing of your results and don't want to open an FSM to try and figure out what you're reporting, but you must have power to the injectors if they spray fuel when you ground the pins at the ECU. You said that you had continuity from Pin 1 at the ECU to the negative side of the coil (I think). If this is the case, and you want to test the whole circuit and the ECU, then take a jumper wire and connect it to the negative terminal of the coil, leaving the other end free but not touching anything. Turn the key on (listen for the fuel pump to be sure that you have fuel), and tap the end of the coil negative jumper to ground quickly. Every third tap, the injectors should click. If they do, that means the circuit is correct and complete and the ECU is seeing the negative side of the coil. If they don't, and you have Pin 1 connected to coil negative, then you might be missing the resistor in the tachometer wire. Or your tachometer is disconnected. The ECU needs that wire and resistor to work right.

Pretty normal for a car that's been sitting for many years, except for the moaning steering rack. If you put the old parts back in maybe they weren't so fine. The good news is that all of the other things have been covered many times on the forums. Check that you didn't put the calipers on the wrong sides with the bleeder on the bottom. you should be able to bleed them even with a whooshing booster. The whooshing probably means that you need a replacement booster.

If the cam is on the base circle (off of the ramp to the lobe) it shouldn't matter whether the chain is loose or tight. The cam's action on the rocker arm is independent of the chain. A fine point, but one less thing to worry about. I use the high gear and roll it by hand method. It's so easy that I bent my license plate on the garage recycle bin. I would rather use the crank snout bolt but I can't get a tool and my hand down there past the fan shroud.

That's why it's a "funny?" story and I'll be driving at low speeds if I ever have to put it on. It's better than a flat spare.

My spare tire has been flat for quite while, it won't hold air since the rim had rusted and pitted from sitting in the water-filled wheel well before I got the car. I was in the wrecking yard looking for a short drive shaft from an early 240Z and thought the local 1971 240Z might have one. The drive shaft was the typical 280Z length, so that was a no-go, but the spare tire in the car still had air pressure and looked in decent shape. So I bought it for $15. I just looked up Bridgestone RD-150 to see what I had and how old it might be and find that it's probably the original 1971 spare tire. 40+ years old. They sold it to me as a "space saver" mini doughnut tire so I guess I'll use it the same way and stay at low speed if I ever have to put it on.

Agree with Blue, take some good pictures of everything, including parts like the distributor advance mechanism. A video of the engine running would be even better, if you have an ECU and an AFM you can get it running on a stand. There are lots of used engines out there but most of them are mystery motors, that have been sitting for years. Somebody who needs an engine would probably pay a premium to know that it's ready to drop in and run.

Thanks for the link. It might also be convenient for connecting an aftermarket engine management system at the ECU connector, with easy added functionality, if it does what I think it does. I couldn't find a simple explanation of functions on the web site though. It looks like a programmable multi-input, multi-output relay.

It's the switches and connections that are the problem, after 30-40 years of time. What is "the ISIS" system?

Looks fairly normal. If you lowered the back end, it wouldn't be so obvious. The wide gap at the top makes the gap in the front look narrow. Compare the back gap to your front tires' gap, with the wheels straight. There's really only two bushings on each side that would let your rear wheel sit forward. The inner control arm (transverse link) bushings. Have you taken a look at them?

Try any old Nissan or Datsun key in the ignition. It will probably work. The ignition locks are usually worn out and any key that goes in will turn it. The door locks are a different story, but my 1995 Pathfinder key will start my 1976 Z. p.s. I wouldn't waste much more effort on it until I saw the title. If he's lost the key and you're getting the run-around, I would bet that the title is unavailable also. Don't take just a bill of sale, unless Texas has really easy title transfer laws.

There was someone on this forum about a year ago (can't remember his screen name) doing the same thing (maybe in reverse, 78 in a 77) and had nothing but aggravation. Is yours destroyed are you hoping that a full replacement will fix some problems? Many parts of the factory stock harness look like they've been "hacked" on but are actually built that way new. Most of the problems in the old harnesses are at the ends where the connections and corrosion are. Might be more worthwhile to work through the problems one by one.

Here's a YouTube video from one of the more popular aftermarket engine management system suppliers, DIYAutotune, comparing a stock 1978 BMW 325IS ECU to their EMS (tuned by them), and including the effect of removing the AFM. Pretty interesting. Of course, it's the tuning that gives the benefits but the tuning is much easier with today's technology.

The 14.4 volts he's measuring at the alternator should also show up as 14.4, minus the voltage drop along the way, at the thick white wire on the starter lug, which should be connected to the battery through the positive cable. That's where it ends up after it feeds the fusible links along the way through the wiring harness. Did he forget to connect the white wire at the starter? He should see voltage at each of the fusible link terminals also. Has he measured there? The charge light is controlled by the L wire, which comes though the VR plug and harness, if I remember right (it's one of the wires that is reconnected if you swap to an internally regulated alternator). The charge light going out when he revs the engine seems to say that the L circuit is there though, since it's feeding back to the light. I would guess that the alternator is bad and is not getting, or properly using, the excitation current from the L wire. More measurements at more points might show something. Edit - found a mistake in the FSM. Deleted my post-comment.

Found some drawings of the three shifter types - http://www.gracieland.org/cars/techtalk/gearing2.html Down at the bottom.

Do you still have the old one? You should be able to count what's left of the teeth. Fewer teeth will speed up the speedometer. 16 is the smallest change you could make to the next level. Here's a link to study, go down the page about half way to see the options and colors - http://www.geocities.com/inlinestroker/ratio.html Looks like you might have a 3.36 and you installed a 3.54 gear. Edit (slow writer) - looks like agreement on 16, color undecided...

Take the cracked one apart.

Just pointing out the reasons that a blanket statement about any single transmission fluid across all Z transmissions, new and abused, is hard to defend. The Swepco blend that I'm using is working well, considering how bad it was before, and I 'm glad that you pointed me that way.