Zed Head

It might be out there but all of those links just lead to a list of eBay Datsun parts. I searched eBay though and I think I found it - Datsun Z Series Coupe | eBay Edit - NOT. eBay or classiczcars keeps breaking the link. It worked once then no more. Try putting these words in the eBay search bar - 1971 Datsun 240z Barn Find Edit 2 - I think it's the "key word" grabber and redirecter that's doing it.Can't remember if that's a GoogleAdsense thing, a site thing, or a virus. Pain in the butt, whatever it is. Turned off "Automatically retrieve titles..." in Advanced. Datsun Z Series Coupe | eBay Edit 3 - didn't work. Still redirectingat.

I'm pretty sure that you could put your injectors on a separate power circuit just like the fuel pump. But there's really no reason not to have enough power to them. The current is dropped through the dropping resistors anyway, they only need enough to open consistently. Gauge power could be put on a separate circuit also.

Did you leave out a link? Your original link ended, sold, at $10,200.

Post #6 here - http://www.classiczcars.com/forums/fuel-injection-s30/52413-78-no-start-w-out-fuel-priming.html I used the "site:classiczcars.com captain obvious pressure gauge gears" method in Google. But it works n the top search box on the forum also, since it's the same effect, through the Google engine.

If I had that problem I'd probably go for a much bigger filter, either make a furnace system work or fit something from the diesel world. I've seen that there was an option for a water separator pre-filter n some early gas engine Datsuns also. GENERAL AIRE Boiler Oil Filter-1A25A at The Home Depot 720 Diesel Work Truck update - Page 2 - 720 - Ratsun Forums - Page 2

There are two types of 260Z's. One uses 240Z suspensions, the other uses 280Z suspension. The dimensions of the springs are in the FSM, in the two Suspension chapters. Measure your "new" springs and see which ones you got. The rear ones are not interchangeable, for sure, so if you got the 280Z style you'll need to keep looking. One way to raise the back of your Z would be to get 280Z strut insulators. They sit at the top of the strut and the 280Z insulators are taller than the 240Z's. Not a great way to do it, but if you can't get the springs it might get you by.

If you're sure the manifold is cracked then replacement is an easy decision. There are quite a few people who have said that headers weren't worth the effort. The stock exhaust manifolds are pretty good, and easier to seal. But if you're set on headers then maybe you'll be one of those people. A tune-up might be a good idea. Might help in the meantime, if you plan to drive it for a little while. But you're probably going to break some things when you replace the manifold. If you're positive that the manifold needs replacing, you might want to wait until you get things back together. Just in case you find damage that is worse than expected. Make sure that you know what type of head you have before you get headers or a replacement manifold. 75-76 is the square port exhaust, later is round. The code is cast in to the side of the head.

Does the engine have carbs or EFI? "Choke" implies carbs, so vacuum leaks are not as big of a problem. What kind of carbs? Could be that the carbs just need tuning. The biggest hose would probably be the one to the brake booster. That can leak also along with the hose that supplies it. The exhaust manifold would need replacing if it's cracked, but it might be fixable with just a resurface of the head-mating surface. Do you know where the exhaust leak is? It could be at the head or at the flange to the exhaust pipe. More details needed.

You might try raising the idle speed to keep it running, while you do more diagnostic work. The rusty screw next to the thing that had the wrong hose on it (Post #5) is the idle adjustment. Turn it out to let more air in and the idle speed will increase. Might be enough to let it idle. Then you can use the old trick of spraying carburetor cleaner (carbs!, yay) around the various spots where there could be a vacuum leak. Injector seals to the manifold, intake manifold/head interface, PCV hose, EGR fittings, etc. If idle speed changes while you spray the outside, that means there's a leak. Keep fixing them and things will get better.

I have an MSA AFM and it works fine. But for a while I thought that it ran rich. But after tuning and cleaning and fixing a variety of odds and ends I put it back on (I had switched to a junk yard AFM that was leaner), I found that it works great now. No flat spots. I would make sure that everything is to spec. first. And I would use an adjustable FPR to lower fuel supply before I messed with the AFM. I think that when you move the preload on that spring you change the position of the air flow - enrichment curve differently than using fuel pressure or a potentiometer. The starting and ending points move, since it's preloaded (low RPM) and it goes full enrichment before maximum air flow is achieved (WOT high RPM). And it's a weird load on the spring with the air acting on a lever, the vane. I'm not sure that changing spring preload simply makes things richer or leaner everywhere. When you use the potentiometer (richer) or fuel pressure (richer or leaner) you keep the shape but move the whole thing up or down. My logic could be off, but there are other ways to get to where you want to be.

The thing about the EFI system is that you can be at the limits of in-range and if they all add up the wrong way, you'll be rich or lean. A few ohms, a psi or two, a vacuum leak, a mis-adjusted AFM. They can add up. The best place to measure coolant sensor resistance is at the ECU connector. It's what the ECU sees. Plus, the ECU connector itself can get corroded, adding resistance. The ECU is not really in a good spot, a lot of water leaks pass by its location.

You didn't mention ignition timing or adjusting valve lash. Those are two basic tuneup procedures. Very important too. Also, the CSV only gets voltage during starting. So, unless it is leaking, it will have no effect on MPG. The idle drop when you press the clutch is kind of typical of running rich. My car does that if I have it tuned rich (potentiometer). Timing affects that also. 40 psi is 10% too high on fuel pressure. But the gauges available today are often inaccurate. Might try another gauge. The first two things that I would do is to check and set the timing, confirming that it does advance when RPM increase, like it should, and check and set valve lash. Also check your cam timing when you have the valve cover off. And, in the future, the actual numbers are nice to see. "Within range" doesn't mean as much.

I don't know what 72 used but my 76 spray bar had a paper gasket between each spray bar block and its cam tower. Looked stock, by the shape and the cut edges. I was just looking at it the other day. I think that it might also show up on the carpartsmanual site. But any sealing method would probably work. It's not a tight tolerance piece, any way you look at it.

Then the hose with no home probably goes to the charcoal canister. But if it's open the distributor advance won't get its vacuum and you'll have a vacuum leak at the throttle body while driving. Your 76 might also have the vacuum advance solenoid, which only allows vacuum advance in top gear. Complicating hose routing. That's why taking notes is good. If you're not familiar with how all the various devices work it's easy to misplace something or leave it disconnected. The diagrams and descriptions are in the Emissions, and Engine Electrical, chapters.

The vacuum comes from the throttle body. It's called ported vacuum and only sees vacuum when the throttle is off-idle. Throttle closed, there's no vacuum. And there are no hoses connected to the alternator. Great that you're digging in to doing your own work, but you should take notes when you take things apart and/or use the diagrams in the FSM when you put them back together. Based on the hoses to the dashpot and the alternator. there may be other things connected not-quite-right. That could be part of your problem. Off the bat, I'd say that your vacuum advance hose to the distributor does not have a vacuum source. Just a guess. Every hose and wire has a specific purpose and needs to be properly attached. You said that you checked the firing order, but did you check the rotation direction?

Sometimes the tachometer will give a clue. If you're in gear, engine turning, and power disappears but the tachometer still shows the engine turning that would mean you still have spark. If the tachometer drops to zero immediately but you're still coasting in gear with a dead motor, no spark, maybe the module, or the coil, or power to either/both. If the tachometer starts jumping around or reads abnormally high or low, it might be the module. Not a 100% clue about the module, but might tell something. Forgot one thing, that I just recently figured out on my car. One of the PO's of my car had jumped the two pickup coil wires together at the junction box. I never really figured out why until the other day when I was testing old parts to see if they were any good. One of the two pickup coils from that distributor, long since swapped for a better one, was bad. The jumper wire allowed the ignition module to see both pickup coils and use the one that provided a good signal. Short story - maybe one of your pickup coils is bad. If so, the engine would only run when cold.

Doesn't the rear main seal ride on the end of the crankshaft itself? Not a bearing? Just wondering. That's why they make those Speedi-sleeves for the end of the crankshaft. Unless you mean that it was pressed in until it touched the bearing. (Aside - Monroe puts the seal on the crankshaft before installing the shaft.) Might help the process to list all of the problems you were hoping to find causes for. The oil leak, high oil pressure, oily cylinders, etc. And, for your own future pondering, take a good look at the rear main seal area just to see how it's wide open to the crankcase. No oil pressure on the seal. And did you check all of the bearing orientations and locations before removing to make sure that there were no blockages? Don't forget to check the crankshaft passages themselves for blockage. Just living vicariously...

You just need reliable, not powerful. The cam and the transmission don't mean anything as far as the fuel pump goes. Get a stock pump, or try the Mazda pump (search around the internet for model). If your mechanic did all of that work just to find a weak fuel pump, you might still need a new mechanic. By now, using this forum and the internet, you should know more about your car than any of the mechanics you've used. And spark plugs don't get damaged from back-firing.

I circled it for him. That little Sorry game piece shouldn't have a hose attached. The other end of that hose either needs vacuum or supplies it to somewhere.

I broke a center bolt also when I finally took my head off. May be best to use the torque wrench for loosening also. If you can't get it loose at some set percentage (10%, 20%) above the desired torque setting, maybe leave it and try something else. Once you break one you're committed to removal. Better plan some down time just in case.

That's a good catch. So take the plug off, clean it up so it's an open circuit, then leave the plug off and try to start the engine. Much easier than shorting the relay. You've uncomplicated things. I've actually cut the FSM section out on that before but forgot about it.

What was it? A part came loose or there was a vacuum leak?

I forgot to ask what year car also. And if it was stock before you modified. If you browse a few threads you'll see that the more details you provide the faster things happen. Every year of car has subtle differences. When cold, the fuel/air mix is extra rich. After warmup it's leaner. If you have a vacuum leak from the disabled EGR or CSV port, you might be too lean to start. Let it cool and see if it starts. confirm that it's getting spark. Check everything that you worked on to make sure nothing came loose (that's the most likely cause, actually).

The BCDD system is designed to clean up the exhaust from excess HC (unburned fuel) under certain conditions. there's actually a little gizmo on the speedometer that measures road speed, and engine speed is involved too. Has anything else malfunctioned or have you modified some things?

How did it run before you "improved" it? What did you remove, exactly?