Zed Head

I've had a weak ignition module before. Showed spark but wouldn't start the engine without starting fluid. It was GM HEI module though. It would probably help you out to measure voltage to the module and to the coil, with the key On and at Start. Just to verify that the components are getting power when they should. then you can worry about if they're using the power as they should. As for using the power correctly, the ZX distributors use a circular magnet that is easily and often cracked. Have you had the ZX distributor apart to confirm that the parts are good?

I originally installed mine to see if I could fix the hot start problem by adding fuel (it helped the engine run better but you still had to wait for the injectors to cool down). Then I installed an AFM with a lean spot at low RPM and ended up using it to get rid of the lean spot. So I tune mine by throttle feel. A lean spot will feel like a lag in response followed by a surge as the AFM vane passes through the area. Not the best fix, since it's probably rich in other areas, but it's a pretty handy band-aid.

Weird that you would have one removed and ready to go. Why would that be? It's not even oily.

Sounds like you might actually have only the Start circuit connected to the new module and coil. There are two circuits from the ignition system at the ballast resistor, one is the ballast bypass for when you are Starting, and the other is the power through the ballast for when you are running. I'm just guessing, but since you test for spark by cranking the engine with Start, and the engine tried to start but doesn't, it seems like power might be going away when you let go of the key.

They show it as available but if you've checked... Funny, when I took pictures the other day for this thread - http://www.classiczcars.com/forums/engine-drivetrain-s30/48693-shifter-return-spring.html - I spent some time myself trying to figure out how to remove the pin. Ended up using an aluminum rod stuck through the reverse check sleeve hole to drive it out. I'm not really in to selling or shipping parts myself but there's a member here called borini63who sells a lot of parts. Might be worth a note. He posts often on zcar.com and hybridz.org also. Seems fair and reasonable from what I've seen.

Looks like any 5 speed from late 76 to 83 will work. The lever on the rod probably changed in 80 though, when they added the reverse check sleeve. Datsun 280Z Transmission Control Lever & Fork (5 Speed-FS5W71B) (From Aug.-'76) Courtesyparts.com shows new ones for about $50. ROD-STRIKI :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com What are you doing?

Congrats. Maybe you shouldn't have called yourself Hardway. I took a rat tail file to the spindle pin bore and removed the high spots on mine. There were some around the lock pin hole. Ran the pin in and out and kept knocking down the high spots until it went in easy. Edit - I seem to be following CO around the forum...

In looking back I think that there may have been times when I cranked my WTS resistance up (I have a Radio Shock volume potentiometer on mine) and still got some rough running. It helped a lot but didn't remove the issue. I think that's why I switched to the hot injector camp, since more duration wouldn't have a huge effect if the gas is boiling in the injector tip, or it seemed that not all of the injectors were affected the same. I don't really know what data might tell the whole story, for me anyway. We'll know it when we see it. Maybe it's a combination of hot fuel in the rail, hot injectors, and an overly hot CTS. Two things that might cause premature vaporization and one that lowers open duration. Lean, lean and lean. Instead of a fan to blow air, maybe a large electric water pump on a radiator hose. Can't go wrong cooling down the whole engine. I only had a tiny water pump pulling water through the AAR block, which then pulls from the thermostat housing (I said head earlier but it was only the T-stat housing). Depending on which way it goes, the water could have circulated through the radiator and open thermostat or through the block and head. But the flow would be low. It's an aggravation, still worth serious thought. Edit - never answered your question about the ZX switch. I know it worked because I heated it with a heat gun and measured resistance. I know the pump worked and was wired right because I shorted the switch leads and tested it. But even on a very hot day after a long drive, with the temperature gauge up on the high end, the switch never caused the pump to run. Somebody with a ZX can probably tell if they ever hear their fan run. I think I've read a few comments where ZX people never really hear it blowing. Maybe it's a poor design.

I can agree with the coolant temp sensor possibly seeing hotter than appropriate conditions. Actually, that was the reason I installed a small electric water pump with the ZX fan switch to run it. But as far as I could tell the switch never closed. Maybe I was wrong and I just missed it. I had it installed most of the summer but removed it late summer. Then cold weather and winter fuel came, now I get hot start problems on a regular basis. Maybe I should have left it on with a toggle switch to clear out the hot water. So close to a solution. A little more supporting data might make things clear.

The ZX FSMs describe the purpose of the cooling fans as to cool the fuel supply lines. I've messed with the switch from a ZX and something I rigged up to push water through the head and found that the switch never closed under the conditions my engine saw even though I would still get the hot start problem. If you have a switch to run your fuel pump before the engine starts you'll hear a lot of bubbling in the tank. It seems like it's well after the rail would have refilled, if it had drained. I think that it's gas vapors, created as the gasoline flows over the hot spots, getting blown through the fuel rail and in to the tank. My guess is that the heat from the exhaust manifolds transfers to the intake runners and head in the vicinity of the injectors and overheats them. There's only a few mm separating the exhaust manifold from the intake runners at the head, and the first cm is exposed, outside the heat shield. You've got radiative and conductive heating all acting on the material that injector body is mounted in. I wouldn't be surprised if the two inner injectors get it worst since they have an exhaust runner on each side. I might take take my digital contact kitchen thermometer with me on my next drive to see what the temperatures are across the intake runners, just for fun. It would be nice to have a scanner and some logging equipment.

The pin 4 theory sounds more reasonable. Maybe pin 21 is an artifact of some idea that didn't pan out. If I had thought more I'd have realized that I already knew there was no pin 21 since I had compared a 76 ECU to a 78 ECU in the past. 76 has more pins than 78 but both work the same in my car. Same exact part numbers. Federal model. My logic on the what the wiring diagram shows stands though, as far as CSV operation. The diagram shows the normally closed relay to power the CSV, opened either by the resistive heater or the heat of the engine. Both twisting the bimetal strip. That's all that really matters for figuring out how to make the CSV work. The CVS operation stands alone, it has power, a relay through the thermotime switch, grounding through the switch to the block. The wires to the ECU are for something else. You could erase the wires to the ECU and still have a circuit that works, with power supplied through the Start circuit on wire 47. 21 is power to the resistive heater in the TS. Funny to spend so much time on something that I removed a month or two after buying my car. No problems starting even in low 30s weather. Maybe it's pin 4.

Is the other stuck in the water pump?

If you read the description in the image I included you'll see that it says "irrespective of the cooling water temperature" (#3). If you look at the wiring diagram you'll see that my description is consistent with the FSM documentation. "Thermotime" has a time component from the internal resistive heater which heats the bimetal strip casuing it to twist and open the relay (Pin 45 to ground which gets power when the starter is used), and a thermal component, the bimetal strip twists from coolant heat (that's why it's mounted on the thermostat housing). Pretty sure my reasoning is sound. Just sayin', for the record. Still doesn't help the OP get his brother's engine started when it's cold. Edit - I think that the difficulty in looking at the wiring diagram is that it's showing mixed serial and parallel circuits, plus a "thermomechanical" device. Power is supplied to several different spots, the ECU, the relay for the CSV, the internal resistive heater in the TS. But, unlike most relay circuits, the mechanism for opening the relay, which is normally closed, is the twisting of the bimetal strip. The little blank rectangle in the switch diagram is not descriptive enough. Edit 2 - actually, this statement "irrespective of the cooling water temperature" is double-edged and confuses things. I think that they meant the sensor readings, since the thermotime switch is affected by cooling water temperature, therefore would affect the the enrichment if Pin 21 does what I've suggested. Maybe lost in translation. Who's got an oscilloscope and some free time?

I think that Pin 21 is used by the ECU enrichment algorithm to determine whether or not the engine is cold or has been cranking without starting for a while. The descriptions and this diagram imply that, in addition to the CSV enrichment, that there is also an injector pulse duration enrichment. Two independent Start enrichments.

Some of the conversions don't put the bleed valve at the top of the internal cavities. A bubble gets stuck above the bleed valve. Other people have actually removed the calipers and oriented them to get the air out, with a piece of wood between the pads to squeeze on if they can't get it on the disc, then reinstalled after they're bled. It's also possible to put the stock calipers on the wrong sides, with the bleed valve on the bottom. I think that a missing reaction disc just makes the brakes more off/on. The reaction disc smooths application of the booster pressure, I believe.

I think that wire 46 should be the ground for the CSV. 45 is the power to the internal heating element. 47 is power supply to both. And 21 is probably the signal to the ECU to have it add enrichment through injector duration. Have you run the test on page EF-23? That test is for the switch itself, but at the ECU connector. Or you could test at the thermotime switch. When it's cold there should be continuity through the thermotime switch pin 46 (page EF-24) to ground (the block) and some resistance (probably 60 ohms) on pin 45 to ground. Teflon tape might screw up your ground and won't let the switch do proper grounding, since it's through the switch threads, if you've had the switch out and did too good of a job re-installing it.

I took the striking lever out of a tail shaft housing that I had from a blown up 5 speed I used for a 71C bellhousing conversion. It's from an 81-83 ZX so it has an extra "reverse check sleeve" that the earlier 5 speeds don't have (shown in the MT chapter of the FSM). Took a picture of the "valley" that the centering plunger rides in. You can see that the ramp up to the 5-R position is steeper than the 1-2 position. I had already removed the plunger so it's not in the picture but the striking lever, its locking in and the reverse check sleeve are shown.

It's great that you're doing the calculations to figure out what's right but you're off-track a little bit. It took me a while to get things straight when I got back in to cars, besides the fact that I never really knew what I was doing when I used to work on them. The intake vacuum that you're measuring is in inches of mercury. You can convert that to psi and subtract it from 36 to determine what your fuel pressure is at idle. That's why you're getting 28 psi at idle, because the fuel pressure regulator is reducing the fuel pressure to give 36 psi against atmospheric pressure. When you lower the pressure in the manifold (create a vacuum), the FPR automatically compensates so that the same amount of fuel will flow for a certain injector open period. The key is remembering that we all live in about 14.7 psi pressure, outside the manifold. In a turbo application, fuel pressure will go down with vacuum and up with boost, varying with manifold pressure. Edit - and my point about the FSM procedure was that there's no intake vacuum when you run the pump alone. So 36 psi with no vacuum (like WOT) is the spec.

If you read the test procedure in the FSM you'll see that there is no intake vacuum applied to the FPR when the test is performed. Your numbers all look good.

All of the work to get things oriented mainly just affects where the distributor rotor points, therefore which spark plug gets the spark when it is initiated. It is odd that what you describe seems backward from what the FSM describes. But there are many adjustments and ways to mix and match parts. The guys that know a lot would just look at where the rotor is pointing at TDC on compression, set that as #1 and go from there. You might be non-stock, but all that really matters is that you can set and measure timing. Added a picture just for fun.

So, you're saying that either, somehow, the distributor shaft was forced in to the wrong orientation in the beginning or you forced it in to the wrong orientation to make it work. As designed it will only install one way, since the aligning slot and its counterpart are offset to one side. You would have to put some effort in to get it jammed in the wrong way, I assume. When you say that you flipped the "oil shaft" do you mean the distributor drive shaft? Or did you remove and reinstall the oil pump? Just trying to clarify for future reference.

That picture jogs my memory. The projection on the metal slug fits in to a slot I believe. It has to ride up a ramp, going either way, against the spring pressure to move the lever over from center to either the 1-2 slot or the 3-4 slot. I think it has to work even harder (move higher) to get to 5-R slot. I think that I realized at the time that it didn't really stop the lever from going from 5th to Reverse, it only centered the lever from side to side. As EuroDat says, it's a good chance that's your problem, since that's the weakness you described. As you can see it's metal. I might have used one of those magnetic pickup tools that looks like an antenna to get the slug out of the hole. You'd probably have to break it to fit it into the tunnel space. I might have that backward or just wrong, but I looked at those parts and couldn't see any way to to make Reverse more difficult to engage, from 5th. The 5th to Reverse action is controlled by the balls and springs in the adapter plate, as Nissan calls it, the iron plate between front and back. I think that the 71C has a special lever gizmo that locks out Reverse. Fun stuff, the fine details of these transmissions.

Can't get enough of the carpartsmanual site - Datsun 240Z/260Z Engine Mounting (Manual From C/# HLS30-46001, RLS30, GRLS30) L24, L26 (To Nov.-'74) Datsun 280Z Engine Mounting L28E

The top of the shaft that you see when looking down the distributor has gear teeth on the bottom end. It's those teeth that can be off the mark. There are actually marks on the oil pump parts and shaft also that need to line up before you install the pump and shaft (quill?). Described in the EL chapter of the FSM. 11:25 is the correct "time", also. Described in the same place in the FSM. Datsun 280Z Oil Pump L28E Note, I could be wrong, I've never had my oil pump off. Sometimes I get involved just to figure things out for my own future use.

I've removed the reverse spring and "plunger" (23-26) from a 1978 5 speed. The bolt and spring come out easy, but you might have trouble getting the plunger out. I think that it might be plastic, can't remember. Maybe your plunger has worn out. I took it out because it was too easy to hit reverse shifting down from 5th to 4th. Never did improve it before I swapped transmissions.