Zed Head

The control relay and the pump relay are both in the engine bay under that cover. There's a diagram on page BE-6 (edit - went ahead and added that picture too). I don't know how comfortable you are with wiring but a jumper wire at the connector (circled in the attached drawing) should run the pump just fine and completely bypass the control relay. A paper clip might do the job but make sure it doesn't touch any metal. It's connected directly to the battery and could short. As soon as you jump it the pump will run. While you're there, take a look at the control relay. If it's dirty and corroded it might need a good cleaning. They can be disassembled. But try the jumper wire first, that will tell the story on the control relay quality. CO might have some comments. He has dug much deeper in to the system. I'm suggesting this because it would be easy if you don't mind playing with electricity. A few screws, remove a plug, add a paper clip. More knowledge.

I looked at your post #35 video and think that maybe the starter issue is the starter letting go when the engine first pops. Hard to tell, but the big buzz when it doesn't start seems wrong. Usually the starter gear will stay extended and engaged as long as you hold the key to Start. There's a ratchet mechanism in the starter gear that will let it spin when the engine starts. But that wouldn't fix the slow start problem, it would just make it less aggravating. It's the waiting for the starter to stop spinning that's irritating. So really you have two irritations combined - the slow start and the wait for the starter gear. It looks like you've checked everything and it's all working to spec. but you're still not getting enough fuel at Start to kick the engine off quickly. If the CSV is not squirting because the thermotime switch is open, that means the injectors aren't squirting enough. Which might be because the Start enrichment designed in to the ECU, through injector open duration, is not enough. Either the enrichment is not working or it's just not set high enough. OR, and here's another stretch, the starter issue and the slow start issue are caused by the same thing: low voltage. But I think that you showed that voltage was okay, although I can't remember if you used a meter on the starter or just looked at the dash gauge (there's a lot of pages here!). OR, another stretch, your weird "priming" behavior is a sign of a messed-up fuel pump control relay. Slow to stop power, but also slow to provide power. Kind of back to EuroDat's comment in #25. Maybe when you hit Start, the pump doesn't get power for just long enough to cause the slow starting. Try providing full-time power with jumpers and see if it starts quickly. I'd try the last one first. It's pretty easy. You might be able to jump the fuel pump relay plug in the cabin instead of running a bunch of wire to the pump. Just let it run, that's what it does when you're driving. Won't hurt.

Mario, you should really wait until you've at least gone through that tank of gasoline. You're spending a lot of time on something that might not be caused by your car at all. People get bad fuel all of the time. EuroDat found gallons of water in his tank, no idea where it came from. The FSM suggests that the thermotime switch provides power when the sensor is somewhere between 57 to 72 degrees F. If you're at 70 degrees you're at the high end, odds are a new one on't provide power either.. Try wiring in a switch to the CSV before spending $100 on something that many people throw away.

I hold my throttle wide open to start the engine faster when it's cold out, since I've removed my CSV. All the ECU knows is that the engine needs 27% more fuel when the TPV is on full throttle. It works, and I've never seen any documentation anywhere that there is special circuitry to reduce fuel enrichment by holding the throttle open and using the starting circuit. And the 1978 system is essentially identical to the earlier systems in functionality. I've had all of the various ECU's from 75 to 78 in my car and they behave the same way. I've seen other people describe this flood-clearing mode for other cars but Nissan is pretty clear in the FSM's about when enrichment happens and when fuel cut happens. I just went through the 1995 Pathfinder EFEC chapter and can't find any reference to fuel cut, except for during deceleration or high-speed operation (RPM limiter, maybe?). Flood-clearing on a modern EFI system would be kind of ironic anyway. The system is designed to adjust timing, and fuel, and engine speed to start and keep running reliably every time. The odds of flooding before starting are small.

Pretty sure that in 1978 the closest thing to "clear flooding mode" that the EFI system has is the "avoid flooding" feature of the heating element in the thermotime switch. The technology is primitive. And CO has proposed that the "priming" that is being done is actually an artifact of a slow-reacting fuel pump control relay. It's not a design feature, it's an error. I think that the starter licking out doesn't show up on all of the videos. But my 1978 parts car did that and it made starting a pain. I had to keep trying until I got a good catch. If I recall right, the starter had some damaged teeth. Cause or effect, I'm not sure.

CO explained this way back in someone else's thread. The injector circuits are wired in parallel and have a common connection for power, and at the ECU transistors, so there's potential to ground on both sides of a plug if you measure one at a time. I think that if you unplugged all of them (or some smaller sub-set) and measured you'd only see power on one side. Anyway, it's normal.

Yes, it is described in the Engine Tune-Up chapter of the FSM. The initial timing number should also be on the inside of the hood of the car. But inspecting the breaker plate for sticking is not. It's just one of those old Z car things, they tend to get rusty eventually. But the first thing to do is to check your timing. If the breaker plate is stuck it will be advanced. If you do check timing with a light, you can spend some time revving the engine and watching what happens to the timing. There are two mechanisms to advance (increase the number) the timing, once is centrifugal (RPM-based) and the other is controlled by intake manifold vacuum. It's the vacuum controlled piece that gets stuck.

Replacing the seal would require removing the spindle pins. It could turn in to a big job for a very small, if any, benefit. I'd say no, leave it as it is, it won't hurt anything.

They look great. Have you moved on from the starting problem? Plug condition is more of a running engine thing. If you wanted to try something on the starting problem, you could wire your CSV to a switch and give the engine a shot of gas before every start. My engine takes longer to start if it's been in a cool garage overnight compared to sitting out in the sun. If it's been sitting in the cool garage it takes noticeably longer than if it's been sitting in the sun for a while. In the sun, it fires up right away. I move my car in and out of the garage often by rolling it, since it's easy, so I've noticed this garage-effect. Residual fuel pressure would be about the same so I'd guess that it's just the rate of vaporization of the fuel. The engine and manifold are warmed by the sun so the fuel vaporizes and lights off faster. This is actually a problem that the government and fuel companies have addressed with "winter-grade" gasoline. They increase the volatility so that engines start faster and run well sooner. I've never seen the exact reasoning described but I would think that a poorly running engine blowing some unburned fuel out the back on startup is a bad thing. Your problem might go away in the fall and winter. Fuel quality varies across the country. You might also check your timing and the distributor advance. If the vacuum advance is stuck it might affect starting behavior. Just one thing I haven't seen mentioned.

I've found that even some "new" parts, like clutch slave cylinders, have honing grit inside. Every operation in a shop costs money, and some of these overseas shops probably pay by the piece.

Isn't that really just a dirt and dust seal? The actual bushing rubber is inside, between the bushing sleeve and the control arm. And the bushing sleeve is pressed against the strut casting by the spindle pin nut. The missing rubber will only allow a little bit of extra water and dirt in to an area that's probably already rusted. Probably not worth fixing.

An old-timey speed shop might have a louver cutting machine and could just punch those in. Or an old-timey locker manufacturing company.

One more vote for get the car titled first before spending more money. I wanted to buy a 280ZX for parts from a guy on Craigslist, here in Oregon, but the guy didn't have the title. He had bought two for parts himself, with no title. He was a lawyer and he didn't want to spend the time to figure out how to get one, and he didn't know the process either. I tried to figure it out and as far as I could tell you had to find out who had the last registration/title and get them to sign some documents releasing it. They will be the registered owner. I'd find out who owned the house and hope that that person is still alive. You might not really own that car.

With the valve springs installed the seal will be tighter. Even hard materials compress and deform a small amount. The valve seat does more than just seal, it also transfers heat. The width and angle of the sealing area is a balance between those two things, determined after many hours of testing and years of usage. I would shoot for a proper contact area width after lapping and not worry too much about a complete air seal with no springs installed. Just saying, it's easy to get drawn in to things that might not really matter much.

Since it was in a house that was sold, it may be that car ownership transferred with the property. Just a thought.

There is a range of years of Ford F150 pickup trucks that use the Bosch pump. For those wrecking yard scavengers. $70 for new is a good deal though. The yard charges about $30.

The way to check FPR and pump operation is to remove the vacuum hose from the FPR, if the engine is running. Or just use the Start circuit if it's not (remove the solenoid wire). The fluctuating pressure is odd. If the vacuum hose was connected, it was going too high. If it wasn't it was too low, then got close to correct. I had an FPR that went rich when it got hot. Took me forever to figure it out. One day it finally went way bad and ran really rich and I realized it had to be the FPR. More tension on the AFM spring makes things lean (less vane movement for the same amount of air squeezing by). If you want more fuel, the potentiometer on the cooling circuit is a better way to go. Speaking of which, the sensor with the ground wire is actually a switch for the timing advance circuit. It doesn't really do much, just advances timing by ~6 degrees when cold, through another circuit in the ignition module and pickup in the distributor. The coolant sensor is the smaller of the two sensors with EV1 (injector-style) connectors. The thermotime switch has a very large body and wrench flats, compared to the coolant sensor. The fact that 60 psi got things running right suggests that injectors might be clogged or there are vacuum leaks. That should be adding quite a bit of extra fuel. Like having 242 cc/min injectors instead of 188 (stock).

I see it now. I'd forgotten how all those throttle linkage parts fit together. Had to go open my hood to refresh. It would be interesting to see the rest of the system to see how it all works. There must be a mechanism in the vacuum can and an electrical switch somewhere. Do you press the throttle to where you want it and lock it? Is it just a throttle lock or does it have some sort of speed-based adjusting mechanism using engine vacuum? More stuff to cause problems...

Both pictures, site's and snake's, show a switch on the brake pedal too. Electrical, and looks like one of the hoses from the can by the booster might attach to the brake pedal switch. I'd be with CO, on some sort of primitive cruise control but I don't see any throttle control, unless it has some sort of air bypass around the throttle blade.. Maybe it's a starter lockout system, for safety. Edit - find out where the ends of those two hoses attach.

That sounds like a typical body shim.

Moi? There was discussion that the car might be an almost original condition, low-miles, "survivor" type car. But it looks more like a normal, been worked on, not quite right car now. More fun in the long run because you don't have to worry about ruining something special. Considering the loose wiring and the missing parts and the fact that it doesn't have what it needs to run anyway, it's in perfect position to get a multimeter, and the Engine Electrical, and Engine Fuel chapters, and the 1980 Electronic Fuel Injection Guide, and just spend some time taking measurements, and making everything right. Then when you're ready to put a battery in it and see what works, you won't get any surprises.

The chain hanging over the clutch pedal and the long black zip ties around the wiring bundle aren't stock Nissan parts. The car is looking more typical.

Wouldn't be too surprising if those missing parts were either borrowed or stolen. It happens when cars sit for a long time. The engine and cooling system might be fine. Check the oil for moisture, along with the fuel tank. The fuel tank probably is full of residue and "varnish" from whatever was originally in there, even if it stayed dry. The engine might have some surface rust so squirting oil around inside the cylinders is a good idea.The tires are dry-rotted probably, but they might offer a clue to age. Get the number from the sidewall and post it. There are codes for later tires. The injectors might be fine too, but the hoses are probably dry-rotted also. They tend to split lengthwise. Same with the fuel rail hoses. But if they've been inside for years they might be okay for a while. The injectors might have residue inside also that will take time to dissolve and flush away. There's a ton of tiny details to look at before you start it and drive it.

You're still not helping us if you don't tell where you got the kit. (Edited some stuff out)...The reason the head is lower diameter than the skirt is for two reasons - there's more material there to expand, and it gets hotter than the skirt area. Here's some terms - http://www.hastingsmfg.com/ServiceTips/piston.htm Here's a really good link from a well known university, used by another well-known university - http://courses.washington.edu/engr100/Section_Wei/engine/UofWindsorManual/Piston%20Design.htm

Don't forget the black ground wire. Similar area, but connected to the negative post, and no fusible link.