Zed Head

His words (Racer Brown's) imply that he knows what the Nissan engineers were thinking and why they had two adjustment holes. He doesn't offer any evidence for retarded cam timing, using a good condition chain and sprockets though. He just offers an idea of why they might be there. The FSM explains in clear times what they're for - adjustments for wear. For the record, I have worked with many engineers and know that passing courses and getting an engineering degree is no guarantee of logical, clear thinking. To the contrary, I have met many engineers who assumed that because they were engineers, that their thoughts, on any and every thing, must be correct. "I have an engineering degree, I must be right." As I said, great for conversation, but don't spend your money on what's said until you see the evidence that it's true.

No offense Leon, I didn't even notice who posted the thread. I've read the article before and wondered then where this guy got his ideas from and decided at the time that it was mostly theorizing. My point was to take it with a grain or two of salt. It's good for understanding what might happen, but short on showing what really does happen. Great seed material for more discussion.

The Racer Brown article is full of conjecture and guesses. A great place to start for experiments and good ideas to be aware of, but there's no facts to back up the claims. It looks like someone just writing down their ideas of what "must be" happening. The two extra holes are most likely there for chain wear as the FSM describes.

The clues do seem to point to exhaust. Seems like a good muffler shop would know what a clogged exhaust system sounds like. The gases don't pulse the same coming out of the pipe. Might be worth having one take a look. Find an honest shop, of course. The lack of vacuum advance could be due to the lack of intake vacuum, which could be related to a clogged exhaust system.

Could be the BCDD. It's purpose is to cut fuel flow and reduce intake vacuum, through a throttle blade bypass channel, above 2800 RPM and 10 mph, under throttle closed deceleration. It's mounted under the throttle body and has a power wire connected. It's the weird looking thing with the rubber boot on it. It's an emissions device so is described in the Emissions section of the FSM.

Kind of stating the obvious aren't you? Experiments that yield measurable results are part of the method. So if someone (the mechanic in this case) has advanced the cam to #3 and felt more "oomph" then they've applied the method, and have knowledge. The discussion can revolve around what oomph means, but if your mechanic has done it and knows what happens, then you can only go off how well you trust him. If he was my mechanic, I'd ask him what he means by "oomph" and what I might lose by doing it - peak HP, for example, if what's described above is correct. If he's just working off internet rumors then you and your engine become the experiment.

Pretty sure that I've seen similar referred to by one of those guys who seems to know a lot, on another forum. One of those old tricks. It's interesting though that people will spend lots of time and money to get their cam set perfectly to the cam builder's specs., using a degree wheel and adjustable timing gear, but will throw an extra 8 degrees of cam advance in for more "oomph". Just an observation about engine tuning. Lots of mystery there, when it comes to cams. If you search around Hybridz, you might find some threads. I think that Tony D had some stories about cam timing tricks. If you're in the waiting room tight now and the question is what to watch on the big screen, the Euro 2012 semi-final is on in about 1.5 hours. If you're in to that.

I know that a lack of timing advance will reduce power, but don't know how much is not enough. Personally, I like to know what the numbers are so I have measured both vacuum and centrifugal (mechanical, centripetal... refers to same thing even though maybe not the right word) on mine. If you have the timing light on and rev the engine up until the mark passes the end of the scale, you'll know you have at least 20. You can probably eyeball it up to 30. Kind of hard to tell since "bog" is a subjective word. One man's bog is another man's hesitation. Plugged exhaust still seems like a potential cause also.

I believe that he's saying that his bushings are too small, not too big. Removing the liner would make it worse. Maybe the bushings are designed like the mustache bar bushings and need a "liner" and IK's are gone.

The vacuum source for the vacuum advance is what they call "ported" vacuum. The port to the hose is closed when the throttle blade is closed and open as soon as the throttle blade comes off of the idle position. So with a timing light, at idle, you might see ten degrees. As soon as you open the throttle a little bit the timing will advance due to the vacuum advance, then as you rev it, the timing will advance even more due to the centrifugal. If you want to test the vacuum advance completely separately from RPM, connect the hose to manifold vacuum. The timing will jump up as soon as the vacuum is applied and drop back down when the hose is disconnected. Leave the hose disconnected and rev up the engine and you can see how the centrifugal is working. If you want to get really specific and measure how much of each you're getting, set your static timing to zero (you'll have to bump the idle up to keep the engine running), then measure vacuum as described with direct intake vacuum and centrifugal by RPM (rev until it stops increasing). You have to set static to zero to use the timing scale, unless you have a dial-back timing light. Vacuum is typically about 15-18 degrees extra, and centrifugal about 20, depending on your distributor parts.

Hey FW, that's a good idea but I think that the AAR is on the fuel pump power circuit. So if he takes the wire off of the starter solenoid and holds the key to Start, he should hear the fuel pump run and the AAR should get power. It does take a little while to close. But that could definitely be part of the high idle problem.

The Z31 master cylinder might not really an "upgrade". It is used to increase pumping volume for use with calipers that require more volume, I believe. If you don't change the calipers, you'll just be increasing pedal pressure to get the same braking force. For what it's worth, the brakes on the 240Z are pretty good. Many of the "upgrades" are more for show, or perceived benefit (these have to be better!) than actual benefit. You might browse through the forums and read up on brakes before spending the money and time.

You can buy straight lines already flared with fittings from most auto parts stores. Then bend them to shape. If the car is down, remove the line and take it with you to make sure on the fittings. Use a piece of string to get length. One option. Why are you asking about master cylinders and upgrading to fix a holed line?

How long has it been running since you replaced the filter and pump? Did you replace them because of a problem? Spark plugs don't go bad all together at the same time, so plugs is unlikely. Timing almost never changes dramatically enough to kill the engine either, unless the distributor breaks. Sudden death is usually electrical, like a bad coil or shorted wire. A simple check for spark by removing a spark plug, sticking it back on the plug wire, grounding the threads, cranking the engine and checking for spark will tell you a lot. Or use an old plug if you have one and do the same. Are you still running points in the distributor or do you have electronic ignition?

How about more information? Is it a 76? Did it run before, or did you just buy a non-running used car with clipped wires that you need for work? Have you checked for spark and fuel? Those are the two basics to look for if it turns over but doesn't fire.

How to properly torque a bolt can raise a lot of discussion. I've read that anti-seize is not recommended on the threads of critical fasteners because it's too slippery and will result in higher than designed tension on the bolt. Bolts that turn without tightening are quite often in the process of breaking (think about the last rusty bolt you thought was coming out then it broke instead). I hope that's not your case. As for retorquing, I think that it depends on the gasket. Some are called out as "no retorque". Here's a description from an actual anti-seize manufacturer on torquing fasteners- http://www.saftlok.com/safteze/antiseiz/index.htm Another interesting page - http://www.mechanicsupport.com/bolt_torque.html Google brings up a bunch on just "anti-seize" and "torque".

How is your ignition timing; static, vacuum advance and mechanical? Have you checked the breaker plate in the distributor (it allows the vacuum advance)? Maybe it's stuck. You can get a good idea of if things are working by watching a timing light and disconnecting the hose to the vac advance canister with the throttle off-idle (to open up the port), then leaving it disconnected and revving it up (to move the centrifugal advance). Retarded timing would cause a power loss. I would spend some time verifying things are working in the distributor.

How did you decide to put the thick side of the rubber bushing facing forward, or on the inside of the assembly? I looked at several used parts I have laying around (came with the salvage yard TC rods I bought) and it looked like Nissan had the thin edged part on the inside. I couldn't really "logic" out a preference and don't really know why they're designed that way, so I put the thin edge in the cup and left the thick edge on the washer, like the salvage parts.

The Harbor Freight 1,000 lb moving dollies are about perfect for holding an engine. Add a few boards cut to width on the bottom, and a couple of 2x4s to hold it upright. The wheels on mine don't swivel as easily as they could but I've had an engine on one for about 8 months now, just fine. Easily rolled around and in to corners for storage. I got the wooden one when they were only $18. http://www.harborfreight.com/material-handling/dollies.html

The diameter was too big. Probably just a plus tolerance in a minus hole. I just mentioned it as an example, sometimes things just don't fit. The second one tapped right in to the proper depth. By the way, the depth is important but it's not super-critical, it doesn't have to be perfect. The end of the mainshaft extends through the bushing, so a mm either way wouldn't matter.

I had one that was too big to go in as far as it should. I had to break it out with a chisel, get a different brand and try again.

They don't go bad that often, so a wrecking yard piece would probably be fine. Plus, you can pick the advance characteristics you want, by vacuum level and total advance, assuming you find the year of car with the right one. Most of the new ones I've seen don't have any specs. so you have no idea what you're getting. Later engines with EGR tended to have a lot more vacuum advance than early engines. Specs for the Nissans are in the FSMs.

Yes, it does look you've covered all the right tests. You might try to figure out why the CSV is on all the time, or run the tapping test without it connected (Edit 2 - looks like you've already done that by trying to run the car without it). I know the ECU has a CSV circuit, but can't remember how it works, I think that it only gets power at Start. I wonder if the CSV was shorted externally to the ECU, if it would cause the ECU to stop firing the injectors. Just a thought. You could unplug the CSV to remove the power and try the tapping test again, or check the CSV wiring for shorts. Check at the ECU pin to ground from the CSV pin, key Off. But the CSV spraying all the time and the injectors not firing is not a good sign for the ECU. Edit - if the CSV is on all the time, it seems to imply a short in the ECU or the ignition relay. If I understand my own notes, the CSV circuit in the ECU only gets power through the ignition relay during Start. But I don't know if it's a separate circuit to Pin 21 or if Pin 21 is a branch off of another ignition circuit. Worth a look. Check Pin 21 for power with the key at Run. Note that these are off the top of my head. The FSM wiring will tell you the CSV works in detail.

No need for pictures of your other cars. The excitement of a 240Z with an LS1 engine should wear down soon enough. Numbers from the LS1 240Z would be more interesting than pictures anyway, 1/4 mile times, track times, etc. That would be the point of the conversion, otherwise it's just a Z with a different than stock engine.

Be careful - Z-Whizz only has two likes so far! http://www.facebook.com/pages/Z-Whizz-Complete-Auto-Repair-and-Sales/154673671235685 From the autotrader ad, for the money invested, and the asking price, you'd think there would be more described. Like is the ZX diff an LSD, what kind of springs and struts (new Gabriels from 1980 or new Illuminas), maybe some HP and Tq numbers, a dyno chart, etc. Money spent doesn't guarantee quality made.