Zed Head

Did the head come complete, with cam, rocker arms, etc., from a running engine, with the new steel valve seats already installed and broken in? Or did you remove the valves and replace the seats? Did you keep the rocker arms, valves and assorted pieces in the order that they were taken out? Just curious, since you might have other problems when you try to put it back together. A little bit of heat would probably soften the old gasket material and make it easier to remove. Makes some people nervous but the gasket will soften up well before any damage is done to the head. A heat gun would work if a torch is too scary.

Don't know if it will affect your decision but that is an F54 block, so might have flat-top pistons, if it came from an NA car. If so, with the N42 head, the compression ratio will be higher than the stock L28. Either way, the head did not come with the block, and the "E30" cam did not come with the N42 head, so somebody has put together their own set of parts. That's not a typical L28 engine.

Flat, straight and parallel is more important than clean. Along with the critical dimensions of valve seats, guides, etc. You're focusing on the wrong thing, if you plan to use the engine to make the car move.

That's probably the best picture of the housing out there, I always forget where it is. Eurodat's probably right, it's just an extra transmitter. Measure the resistance from the bullet connector to ground. If it's a transmitter you'll get a number, if it's switch you'll get zero or infinite.

You might have a 76-77 thermostat housing. 76 for sure has four - thermotime switch, coolant temp. sensor (for ECU), coolant temp. indicator (for gauge) and temp. switch for the ignition module (to use the second pickup in the distributor to advance the timing when cold).

No editing allowed. Weird. Didn't mean to sound harsh above, but a good mechanic should know about the return line on a pressure regulation system. "Discovering" the return line is a bad sign.

There's a diagram of how the fuel system works on page EF-5 of the FSM. You should find a new mechanic. And have the new one measure your fuel pressure.

When I peeled my half-cap off the silicone stayed behind on the dash. The installer had only laid a few lines of adhesive down though. I was able to remove most of it, but I still have spots that are stuck permanently. If you're going to be sanding and resurfacing it probably won't matter. Peel up an edge and see what happens. Get the interior nice and warm first though, the cap is made of ABS or a similar plastic and will crack if it's stressed cold. In case it doesn't come off easy and you change your mind, or you want to try to resell it. Otherwise, just break it off in chunks.

Stick some stiff paper or thin metal sheet between the dash cap lip and the edge of the gauge to make a ramp. Spray a little Armorall or spit on it for lubrication. The plastic will stretch a little, make sure it's not too cold so you don't crack it. I slipped mine out the first time I took them out, with a half-cap. Since then I've removed the cap and see the cracks as character.

More likely that it's stuck open, causing the ECU to supply more fuel. You can check by looking at the bumper for the damper weight under the black cover on the side of the AFM.

The things that you tried that raised the idle that made it run better all leaned out the mixture. Removing the AAR hose, taking off the AFM boot (AFM signal disappears), taking the air screw back (bypasses the AFM vane). Somehow you've made things too rich. Did you adjust the AFM spring? Accidentally knock the coolant temp sensor connector loose? Raise your fuel pressure somehow? You might also have fouled some plugs. Brake cleaner is not designed to burn, like carb cleaner is. The old brake cleaner won't burn at all, I don't know about the new "green" stuff.

You said it ran well with the hose between the AFM and the air filter removed. The only thing between the AFM and the "air" is the filter and the plastic tube to the air intake point. Did you check the rest of the intake system. Maybe you meant the hose from the AFM to the throttle body? If so, it sounds like your AFM vane is stuck closed.

Clogged air filter?

The boiling water method works. The bushing is made of nylon, which absorbs a lot of water. The absorbed water plus the heat soften it up and it will pop off. Boil it, then try the adjustable wrench method while it's still warm.

Looks like Nissan may have them, for a couple dollars more. If "insert" means seat. Look at parts 5 and 6 - Datsun 280Z Cylinder Head, Rocker Cover & Thermostat L28E INSERT-VAL :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com

Coincidentally, today I was looking at a few ECU's I've collected to see if they had the "altitude compensation" pins. All of them are A11-600-000 and they come from cars from 76-78. While checking the FSM's I saw that only the California cars came with altitude compensation. I wonder if the -601- ECU's have the altitude compensation circuit? Samson is in CA, Eurodat, where did your car, or ECU, come from? The switch is described and shown in the Engine Fuel chapter, it drops the fuel supply through the injector duration by 6% when the switch closes due to low pressure from high altitude. It wouldn't affect operation unless the switch was shorted, causing a lean condition. Samson, your mechanic doesn't understand how the injection system works. The injector connections have 12 volts on both sides due to the way the transistors operate (I confess that I'm not clear on why that is either, but it is). The injector solenoids don't activate until current actually flows when the transistor circuit allows it to. 12 volts on both sides is good. As I said in an earlier post, you're pretty close. I had to adjust my idle air screw and install some new plug wires on my last DEQ (our emissions checkers) visit here in Oregon. A miss will spew unburned fuel (bad), and the idle air screw can lean up the idle. I wouldn't do anything major and I would find a mechanic who knows old EFI.

Whoever suggested the AFM as the problem might have been thinking of 75-77, which have the fuel pump contact switch. Your 78 should be useing the oil pressure and alternator current to activate the fuel pump circuit. But the fact that your fuel pump has been rewired to be on with the key at On takes the fuel pump safety circuit out of the picture anyway. Here's one possibility - whoever rewired your fuel pump to come on when the key is at ON, bypassing the safety circuit, might have it wired so that it actually turns off when the key is at Start. Turn key to On, pump turns on, pump turns off when key is turned to Start, engine fires then dies because fuel pressure dropped, fuel pump comes on again when key is released, second try works. Just a wild arse guess and still doesn't really fit what's happening well. Your symptoms are weird so even the troubleshooting chart will be difficult to use. The first thing you might do is determine if it's spark related or fuel or electrical (loss of power to the EFI system). Get one of those flashing spark testers for a plug wire and watch what happens on the first start, if spark disappears before the engine dies that will tell you something. Or measure fuel pressure while starting. Or use a Noid light (I still don't really know what noid means) or christmas tree light and see if the injectors stop firing before it dies. Don't buy a new AFM or CSV. The symptoms don't fit.

I think that the ECM gets its signal from the negative post of the coil, not the ignition module. Are you sure that you're getting spark? No spark = no ECM signal = no injector grounding through ECM transistors. Of course though, the same applies for spark - no reluctor pulse from distributor to ignition module = no spark = (see previous). That's the chain of events, assuming that you have distributor-controlled timing and not a CAS (you have a ZX right?).

You can buy a complete engine with accessories (head, block, alternator, distributor, AC, power steering, manifolds, etc.) from the local PicknPull here in Oregon for $240. With a 30 day guarantee included. Electronic distributors are ~$42. That $300 is easy money IF you think you're done with the L engines. Otherwise, it's nice to have a known-good engine as a spare. http://www.picknpull.com/part_pricing.aspx?LocationID=119&Language=English&NavItem=3&SearchCriteria=partpricing

I bought a set of those. I just drilled holes where necessary. Use the plastic base a template for the holes to make sure it seats right, it shouldn't be difficult. They fit really well. I really like the way mine look. Much better than the old torpedo shape. Since we're giving opinions on esthetics. And having a passenger mirror is great, I don't know why Nissan didn't put one on originally. I did have one problem with mine when they arrived. One of the lenses was warped and gave a fun-house mirror image. I called MSA and the guy I talked to said he'd not heard of that before but they paid for shipping back and replaced it. I was only out waiting time. Check the image before installing. The one downside I found to the mirrors is that they're noisy in the wind. With the window down in the summer you can really hear it. I could cup my hand around the mirror and knock down the noise but it gets old after a while. If you have a quiet car and like to hear the scenery going by, they're a little irritating. I've had my eye out for better mirrors but haven't found them yet.

My old thread, back to life! If the rewire worked for a couple of months, I would have the battery and alternator tested, or test them your self by disconnecting either and seeing if the drain stops. A shorted alternator will drain the battery and a bad battery might not take a complete charge. And check the remaining wires from the conversion, one of them is hot all the time on the 76. It might be shorting to ground. No idea about the relays not affecting the brake warning light. Maybe Nissan moved the relays in 77. Odd. You did mention one other thing that's not quite normal - the voltmeter should be on all the time not just with the key on. But that might not matter. Assume that your car is normal and check the normal stuff for a battery drain, the battery and alternator.

The video sounds a little bit like low fuel pressure, from the fuel pump stopping when the key is let go. 78 uses the alternator or the oil pressure to keep the fuel pump running, either one. Maybe your switch is bad and/or the alternator is not kicking in soon enough. Watch your voltmeter and see if it jumps above where it sat before starting.

How much effect will there be having the same rate front and back, compared to the lighter rate front springs in the stock setup?

Could be the auxiliary air regulator (AAR), It might be stuck closed. It's designed to let more air in for a few minutes so that you don't have to hold the throttle down or blip it. It's the torpedo shaped thing by the throttle body with a large hose connected to each end.

Anybody know what's going on with the hybridz.org site?