Zed Head

Make sure that your floor jack doesn't leak. It's a great irritation to have the elevation of the transmission slowly changing while you're trying to get things lined up. And make sure you get the car high enough to slide the transmission out before you start. It's possible to get it removed but stuck under the car, requiring more wasted time running around re-adjusting the jack stands. Plus, beware the trans tipping off the floor jack, unless you're going to bench press it out and in like some do.

Here is an expensive replacement - http://www.thezstore.com/page/TZS/PROD/11-3470 I don't think that the diode and resistor measurements are critical, from my limited understanding. They are there mainly to stop electrical spikes in the circuits when the contacts open and close (I believe it might be referred to as "flyback" - http://en.wikipedia.org/wiki/Flyback_diode) Here's another link with some recommended diodes for a similar purpose - http://www.bcae1.com/relays.htm More info - http://www.rvsafetysystems.com/Relay%20data%20sheet.pdf If you're thinking about trying to make your own, you probably know this anyway, but just in case. Looks interesting, if you get it to work. You might find a stock Datsun replacement on EBay also.

You should really give more info about the collection of parts. Stock cam, stock heads, stock head gasket, initial timing, total timing, EFI, stock intake manifold, etc? I think that that is where the problems come from when people try to run high compression. Without the details it's just a head designation number and a piston. And your 10:1 CR doesn't quite match what the stock N47 flat top combo should give, unless you rounded up, according to available information. 9.75:1 is what I've seen. Not to mention the gasoline quality. In Oregon we only have up to 92 octane 10% ethanol fuel at the common gas station. The detonation is in the details.

Flat top pistons came out with the P79 head. N42 blocks came with dished pistons so it looks like someone installed flat-tops in a typical N42/N47 engine. With an N47 head you will have a higher compression ratio, and if the predominant word on the internet is correct, detonation problems on pump gas. There are some out there who install the flat-tops just for the higher compression ratio,then retard the timing to avoid detonation. Some have reported that they don't have to retard the timing and don't have problems. Others have reported constant problems. It's hard to tell what really works. One option, if you keep it the way it is, would be to use a thicker head gasket to drop the CR. Check out this calculator - http://www.ozdat.com/ozdatonline/enginedesign/ Under Pistons, "L28 Late" would be flat tops, "L28 Early and Turbo" would be dished. Or you could get a P79 or P90 head and be back to a normal late model L28 NA style engine. Or run the higher CR and see what happens.

The intake system pulls a vacuum on the crankcase when the PCV system is connected properly. So any leaks in the PCV or through the valve cover gasket or the big hose from the valve cover (actually part of the PCV system) are leaks in to the intake manifold, bypassing the AFM vane, causing a lean condition. All air must pass through the AFM for the EFI system to work correctly, no exceptions. Are you sure that your PCV is missing? There's not much to it and looking from outside (how did you get your eyeball under there?) it looks like a flat disc sitting in a metal fitting. They do get gummed up (maybe that's the carbon), but can be cleaned with some carb cleaner. I had the contact switch in my newly rebuilt AFM stop working right after I got it. I think that a small piece of debris got on to the tiny contact switch and kept it open. I never found whatever was holding it open, but after I mucked around with it and put it back together it's worked fine ever since.

The main benefit to electronic over points is lower maintenance. What benefits are you looking for? Edit - took some vague comments out.

FastWoman is right, the AFM's for 1976 came with the fuel switch in them and your symptoms sound like yours is not working. The switch is bypassed during Starting, but comes in to play when the key is at On. So if the switch doesn't work, the pump will turn off when you let go of the key. The engine then runs until fuel pressure drops. It's odd though, that the engine ran with the other AFM, since it probably would not have had the switch if it was the wrong one. There were only a few years that used it, and I think that they all were the same AFM model. What are the AFM numbers? There are pictures on the atlanticz site of the switch. It's under the black cover. You can bend the rod that moves the switch to make it work correctly, if that's the problem. http://atlanticz.ca/zclub/techtips/afm/index.html

Cut wires will typically give a nothing response, not a sometimes response. Low voltage through or to a relay will give a sometimes response. Wouldn't hurt to measure the voltage at the starter solenoid while trying to start the engine. Reattaching cut wires can have unintended consequences.

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The B.E.G.I regulators allow the addition of "extra" fuel, by increasing fuel pressure at a greater then 1:1 ratio under boost. Here's a link, I can't find what B.E.G.I. stands for but I think the B.E. is Bell Engineering - http://www.bellengineering.net/PDF/FMU%20Instructions.pdf Apparently the one referred to in the link is used along with the stock regulator. Either way, you don't need a boost referenced or rising rate regulator with your NA engine. But you really should measure your pressure under load as recommended in your other thread. The more you know, the less "extra" money you'll spend. If you do decide to go with a new regulator though, I would avoid the Aeromotive brand. No offense to FastWoman (she mentioned the brand in the other thread), but I have one and although it is well-made and works great while the engine is running, it has a basic design flaw which lets the pressure leak out rapidly when the pump is turned off. If I don't prime the rail before hitting Start, the engine will crank for a long time before starting. It's a good anti-theft feature and might be indirectly helping the "hot-start" issue (with fresh cold gasoline) but it's kind of tiresome to wait for the rail to pressurize after every stop.

Use the word "Ford" in addition to those LeonV suggested. You'll find some fixes.

I pondered that but wasn't sure. All I see in the pictures is a Tee fitting. So I conjectured.

If you did these tests with the key at On, it looks like your Fuel Injection harness fusible link is blown, disconnected or has a corroded connection. It is the single green wire, that looks like some sort of extension with a connector on each end, connected to a white wire directly from the battery positive terminal. If it is in its original spot, it may be attached to the side of the relay box with a long plastic peg. OR, your FI and Fuel Pump relay is bad. It is combined for the 1976 model, attached up above the hood release handle. A silver box, about 1 x 1 x 2". With the key On you should have battery voltage at the dropping resistors, they are fed directly by the EFI/Pump relay, which is on the circuit with the FI fusible link. There are some good diagrams on pages EF-25 and more in the FSM. EDIT - Blue covered the relay in Posts #3, 4 and 5. That's the one. His diagram shows where the link is also. It's green.

The clicking behind the dash is probably an effect, not a cause. When the engine RPM drop the fuel pump contact switch in the AFM opens, killing power to the fuel pump relay. Then the mixture leans out, engine RPM goes up, the contact closes again, and repeat. Usually good for a few clicking cycles before the engine dies or it smooths out. Have you measured fuel pressure? It is one of the most important variables in an EFI engine. Another possibility is your ignition module. Next time it starts running poorly, with bucking etc., stop and turn the key off. Then restart it. If the problem goes away temporarily that's a good sign that the ignition module is going bad. I could get my 76 module to do that when it went bad just by taking it to about 3200 RPM. Turn it off and restart and I could drive around all day below 3000 RPM. The dipping idle might be because your air/fuel mixture at idle is all out of whack now. If fuel pressure or the module turn out to be the problem hopefully you can get back to where you started. And the two white wires are apparently for some sort of diagnostic test. Everyone has them and they're all disconnected.

34 and 25 aren't that bad, as FastWoman suggests. The 25 psi with the vacuum hoses connected is an indication that you actually have fairly good intake vacuum, since intake vacuum is what moves the FPR diaphragm to drop the fuel pressure. The 48 psi before the fuel filter (I think that's what you meant, not from the filter) seems kind of high. You might have a partially clogged filter. But I don't know what a pre-filter pressure should be, so can't really say. Your car should run fairly well though with the vacuum hose connected to the FPR, at those 34 and 25 psi numbers. It might be somewhat lean, but not dramatically. What do you mean by "waaay better" and did you let the engine get to full operating temperature? It will run way better with a rich mixture when it's cold, but will run worse when it's hot. You might do a little more investigating before you spend the cash on an adjustable FPR.

A short stroke with a 3 pound maul on a good tight wrench might work. Heavier is better so that you can spend more effort on precise aiming and less on swinging. How would you extract the broken head bolt without removing the head? I might be more worried about that than the lash adjustment, it could be a sign of bigger problems. How did it break? And what does carbon-filled mean? Do you have some numbers on your current lash settings? I'm curious about how loose they are, and how they got that way.

You should give more details. Car dies after 20 seconds doesn't tell much. At least you mentioned the year. Is the car new to you, did you just work on it, did it run before, etc...? 75s have a fuel pump switch in the AFM, that closes when air is flowing. It's bypassed during starting. You can read about in the Engine Fuel section of the FSM. Sometimes they'll get some crud in the contact and break the connection. It's behind the black cover on the side of the AFM. SteveJ didn't mention it but the link to the FSMs is in his signature.

Doesn't the mechanical fuel pump move in synch with the cam?

Thanks for the story. Seems amazing that the valves could tap the pistons at that RPM and piston speed and damage the pistons (although "smiles" might not count as damage), yet not get damaged themselves. Good luck with the new engine.

Just curious, but are you saying that the valves floated and hit the piston, causing the crack, or that the stress of over-revving over-loaded the wrist-pin area of the piston, causing the same? Are the valves damaged? I've seen it suggested that the L series valve train will rev to 8,000 RPM without float, so valve float at 7,500 RPM might be unusual. Still learning the limits of the engine design.

Arne will probably get back to you, but in the meantime if you're in a hurry, I can say that it is possible to drop the strut out of the tunnel if you remove the parking brake cable and the brake hydraulic line. Put a jack or some blocks under the control arm, remove the three nuts, then push the strut inward as you drop it down. It's not that hard to get it out and hanging off of the inner mounting bushings. On installation, put a jack under the control arm and get the three studs very close to going through the holes during installation, then use your foot to jack up the last few mm while you align the studs to get them through the three holes. By the way, I think that you could lever those bushings in without sanding, with some thin, greased steel putty knives or similar. They will guide and compress the urethane as you press it in to place.

Download the FSM. Open the the Engine Fuel section. There is a sub-section for Removal and Installation - http://www.xenons30.com/reference.html

There is also a check valve at the outlet of the fuel pump. FPR at one, check valve at the other, to hold the pressure. The check valves do fail occasionally, search the term and you'll find a few threads about it. superlen is right about the AFM vane and the fuel pump contact switch. But the Start circuit (key at Start position) does supply power to the fuel pump directly. When the engine starts and you let the key go to On, the AFM vane switch takes over. That gives one way to check the pump and fuel pressure without starting the engine - remove the wire to the starter, then turn the key to Start. The fuel pump will run, but the engine won't turn over.

It's described in the Engine Fuel section. The pump should only have power at Start and when the engine is running. Two possibilities are that your fuel system might not be holding pressure or your cold start valve is not working. Sounds more like a fuel pressure drop. Will it start when warm, after a very short shut down (before pressure can bleed off)?

Thanks for putting that video up. I've read the stories in the past but had a hard time comprehending what I was reading. Sounded like you were taking a few frustrations out on the ECU the way you beat on it. Or maybe it was just the recorder.