Zed Head

No timing light? I don't see any measurements. The engineers put those degree marks on for an important reason. It's important. If you've confirmed where zero is, with your screwdriver method, then you can set ignition timing to its correct spot. If you set and measure spark at the correct spot then you don't have a timing issue anymore. When you have that locked down then you'll know that your problems are somewhere else. Best not to solve two problems at the same time. You're lucky in that you have an engine that runs. From here it's a matter of confirming what's right, and making the stuff that isn't, is.

I couldn't even log in to my email account, Hotmail (aka Outlook) without javascript enabled. It's just email. I'm so tied to Hotmail/Outlook it's pitiful. Outlook sucks and Microsoft knows it and they don't care. 'cause they got you. Millions of people interact with Microsoft through email, and their email program is a giant steaming turd. Seems weird that they don't shine it up a little bit.

Well, the fact that it runs well with the pump off and bad with it on suggests a problem either way. Knowing fuel pressure is important. If fuel pressure measures correct check the vacuum hose to the FPR for fuel. IT should be dry. You can have good pressure but too much fuel supply due to a leak through the FPR diaphragm. Not uncommon to blow a diaphragm and fight a "running rich" problem for weeks or months. It's sneaky. Dielectric grease seems like a good idea and wouldn't hurt. But it makes everything greasy. If you drive it fairly regularly any corrosion you cleaned of should stay away. It's the sitting out in the moisture that causes the problem. There's a diagram at the beginning of the Engine Fuel chapter that is pretty good. Gets you close. Most of your measurements will be at the ECU connector though. Use the 1980 EFI Guide, it's very good. Covers all years up to 1980.

There's a technique involving a long screwdriver on the valve spring retainer with the camshaft as a fulcrum that you could have used. To remove the rocker arm, then set the pad in place. For future reference. They seem to pop out on older, probably gummed up, engines when people rev them up after getting the going again. Not uncommon. Hopefully you're good to go for a while.

Compression ratio is almost a useless number without knowing the cam specs. Cylinder pressure is what causes detonation, so higher pressures will lead to a higher likelihood of detonation. But, due to the variation in gauges out there, the range of the numbers measured is huge. In an ideal world, we'd all use calibrated identical pressure gauges and we'd talk about designing for a certain static cylinder pressure. From that starting pressure you can get in to taking about dynamic changes. CR alone doesn't tell you a whole lot though. It tells you which way you're going but not where you ended up.

All it really takes is one vacuum leak causing a low idle speed to allow the AFM vane to get too low and voila, a switch is installed. I would start by running the tests in the EFI Guide and/or the FSM. There's a test for the combined EFI/pump relay. It runs now, which is way ahead of many people's projects. If he removes stuff and it stops running then he's in a whole 'nother world.

Anybody out there noticed a new type of ad that pops up in the middle of a column of text while you're reading and plays a little video? Not on CZCC but other web sites, like the newspaper sites. Over the last few months I've spent more time clicking the little X in the upper right corner than actually reading. They seem to be everywhere. Can't think of a more annoying way to advertise a product. I blocked Flash in Chrome and they're gone. It even stopped autoplay videos on ESPN, a massive bonus. Edit - I knew this would happen. They came back. Never mind. It's probably javascript. The internet is messing with me. ESPN autoplay is still fixed. Edit 2 - Disabled javascript and the ads stopped but so did a bunch of other stuff. Some sites won't even load up. It's like they're all saying **** you, you'll watch our ads or you'll get nothing. I'm going to run lean, no ads, and some sites not accessible and see how internet life changes. I'm betting it will be better. Those video ads were killing me.

Changing the thermostat is super easy. Get your thermostat at this place and get a new gasket too. https://zcardepot.com/engine/cooling-heating/thermostat-160-degree.html https://zcardepot.com/engine/cooling-heating/thermostat-gasket.html MSA has them also. Kind of hard to find on their site but they're there.

How long will it idle with the pump turned off? Could just be residual pressure from flexible fuel lines. I'd let it idle until it dies to be sure. The fact that it runs rich when the pump is on indicates that you have one or more of the common Z EFI problems. Do not adjust the AFM, unless it's already been messed with. If you find that, adjust it back to where it started. Your best path to getting it running well is to go through the tests in the EFI Guide. Clean and check all of your electrical connections. Read through the Engine Fuel chapter of the FSM and you'll see how the fuel pump circuit works and why the PO added that switch. If the engine runs right you shouldn't need it. It's a band-aid.

How far off was the lash on the valve that lost its pad? Curious if the PO adjusted it to run without the pad, or if the pad just fell off and he/she kept running it with no adjustment.

That's a lot of K&N bashing above, but those nice-looking foam pieces that people use on their ITB's or carburetors are probably worse. Just know the tradeoffs is the message. K&N's are dirty filters.

And, just ignore test results if you mean well. It's a top priority, whether it's achieved or not. K&N is a marketing company. Of course, efficiency is undefined so it could mean flow. Plausible deniability.

Check out the filter for the filter. FLOW is important. Until they have something else to sell you. Then, not so much. http://www.knfilters.com/news/news.aspx?id=5690

K&N made their name in the dirty filter area. They can get soaked in water, like when you dump your dirtbike in the creek, and will clear up after you clear the cylinders of water. The competition was oil-soaked foam though, not paper. There used to be ads out there showing how the dirt would build up on the oil soaked outer surface creating more and better filtration. Supposedly the dirt would drop off as it the buildup got too heavy, like some sort of self-sustaining media. I remember being fascinated by the concept of more dirt resulting in a cleaner air supply. Looking back, it was all marketing BS. I copied a segment from K&N's web site that should immediately trigger anybody's BS sensor. Setting the stage, mentally, for flow is more important than clean if you want to "win the race". http://www.nicoclub.com/archives/kn-vs-oem-filter.html http://www.knfilters.com/filter_facts.htm

Run the pump without the engine running and see if you can hear the hiss. Squirt some carb cleaner at the leak area and see if the sound changes. Grab the injector by hand and press it down and see if the sound changes. Pull the injector up and see if the sound changes. Lots of ways to learn more. Not uncommon for the seals to harden over time, then some bumping and moving can create a leak. Would have been super easy to replace the seals while the manifold was off. Still not that difficult. And they're cheap. I have a vague memory of writing this before.

The vacuum cawk, if you have one, also closes the coolant supply off completely at certain settings. Weird how complicated Nissan made their system.

The FPR can make a hissing noise. Did you use new seals and insulators on the injectors, small and large (the round rubber pieces)? Are you using the two-screw clamps? They actually put some pressure on the lower seal by tightening on the top, big, insulator. Does it run like there's a vacuum leak?

No offense intended on the "simpify" misspelling. I left it because it seemed funny. Oversimpify should be an actual word, I think.

The title of your thread is Wideband O2 Sensor. I missed the changeover point. I think that you're oversimpifying. It's a complex device.

Problems like these are why we have hobbies like Z cars in the first place. Worlds colliding here...

The ignition module for the 260Z is by the fuse box n the cabin. It's a cool-looking finned aluminum case. The gear-like thing is called a reluctor (wheel) and the trigger signal is generated when the metal tooth passes by the magnetic pickup coil. The FSM describes it well, at least the 1976 version does. If you start messing with different distributors, check the breaker plate action before you get too involved. Thee are many distributors out there that will trigger the ignition module just fine but won't have a usable vacuum advance mechanism.

You raise a good point. I realized that I don't really understand how the sensors/gauges work either (can't say that I do now either). Innovate has a paper that does a good job of explaining it. Excess fuel left over after all of the oxygen has burned apparently also cause a voltage in the sensor. The voltage is then used in a calculation to give the ratio. Pretty interesting and more complex than I had thought. It's the "pump" that makes the difference I think. http://www.innovatemotorsports.com/resources/news3.php Here's another. http://tayloredge.com/reference/Science/oxygensensor3.pdf One more. http://www.megamanual.com/PWC/LSU4.htm

Easy to get confused, especially since most "high-energy" coils (assuming means coils for high-energy ignitions, commonly assumed to mean constant current systems, like the GM HEI system) are below 1.0 ohm. The GM HEI coil is about 0.7 +/- 0.1., for example. Plus the FAQ's give conflicting information, and say 1.5 ohms is the limit. http://www.123ignition.nl/faq.php

What is the rate of this fluctuation? In other words, how long does it take to go from 800 to 900 and back to 800. How much time from 800 to 800? One second, two seconds, less than a second?

Here's a couple of Articles on electronic ignition. The various extra sensors outside of the distributor are for emissions purposes, to run that extra pickup coil and change the timing based on engine temperature. If you're only using one pickup you don't need them, you can simplify. The electronic ignitions use ~ one ohm coils and no ballast. The common early Pertronix swap isn't a "high-energy" system like the later electronic systems (GM HEI, for example), or the 1978 and on 280Z systems. It's "poinless" so lower maintenance but there are better options out there. http://www.classiczcars.com/articles/technical-articles/electrical/replacing-the-280z-tiu-with-an-hei-module-r67/ http://www.classiczcars.com/articles/technical-articles/electrical/gm-hei-module-install-r69/