sblake01

Well, after looking in the FSM, I realized that all this time I was comparing an 81-83 5 speed, which is what I have in both my cars, to a 77-78 4 speed. I'll admit it, I was wro......

Three steps? Hmmmmm....looks like I'm going to have to read the label next time I use it .

Yeah, I guess my statement was rather broad. I should have said that the onlly 260Zs that I have ever seen with factory air were late ones. Does the early 260Z have the 240Z style dash as Mitchka said? If so, I don't see how the factory AC would fit under it.

I wasn't sure if yours was early or late. That is one thing I found out about 260Zs. Only the late ones got the factoy air. Perhaps the 260Z FSM I have is a mid year revision because there's no way that factoy unit would fit under the early dash.

Spectre, I missed your question. Good thing the 'Array bot' brought this thread back. First off, to Rockr69, and as you found out, 78s don't have the engine number on the ID tag. I have a 78 with the original engine and it's number is L28 275675 so you do most likely have a 76 engine. Looking at your tag the VIN seems to be 464138 not 484138 which would be too high. That makes yours a little under 2000 cars later than mine. What's your build date? That would be on the tag on the driver's door jamb if someone hasn't removed it at some point and there should also be a clearer VIN there. As far as the AC question, R134a puts extra stress on the o rings, seals, and hoses in an R12 system due to the higher pressure.

Throttle opener control valve and servo diaphragm? That's all I've ever known about them as even the FSM doesn't go into any detail. I've had a couple of people I know with 240Zs ask about those and my research found basically nothing. Usually that type of setup has to to with fast idle control on an air conditioning system but I know that's not the case here.

zhome lied. Compare them in the FSM, but like I said, it's all rather moot.

I was comparing the type B 4 speed to the 77-79 5 speed strictly by gear ratio. Not the type A 3 piece 'monkey motion' early 4 speed. My point stands, the gear ratios in the trans are not the same. I won't bother posting the chart. It's already on the site somewhere. If you want to go on thinking they're the same that's up to you. It's really a rather moot point anyway.

Sounds like he was talking about a paint gun.

Not true. Been argued before here and on other sites and I won't argue it any further here but the first four gears are not the same on a 77-78 5spd and the early 4 speed. I'll just say, look it up.

Well put. That's basically what I said but the one word does cover it.

In my case, the agreed value policies I have on my 320 pickup and my Z represent what I have invested in them plus maybe a little more but it wouldn't be enough to duplicate either of them today. Kind of a 'cut your losses' type thing. The market price is such a speculative thing and I don't consider mysely any kind of 'collector' anyway.

But...to answer your original question, those readings in your first post are pretty typical for a stock gauge and oil pump with or without an oil cooler.

It's the smaller of the two sensors on the front of the thermostat housing, the one farthest from the engine.

I'm sorry, I just couldn't resist that. Having worked on 74s as well as all of the other years, I've seen the factory system more than once on a 74 both early and late. It is a factory system and it's the same basic system as the 75 and up. Maybe the early 74s were outsourced but there was nothing that would indicate that on the ones I've worked on. Never worked at Smith Mesa Datsun. Not even sure where it is (was). Those were the only matching dealer frames I could find. I did once work at Pomona Valley Datsun but not as an AC tech.

I've never tried it altough I know they run badly when it's disconnected. I've haven't tried jumpering the connector but I imagine that would about the same as the sensor being cold and would make it run too rich once its warmed up.

It appears that the late 260 uses a unique sending unit. That makes sense because it would have a 280Z type tank but no fuel injection. 25060-N4500 and 25060-N4501 are the numbers listed for 9/74-11/74 in the microfiche. The first number is still good but the second isn't. That's going to be a tough find. You could always ask one of your 'old datsun mechanic' friends or your dad. Remember, the ones that told you that no 260Z had factory air conditioning?

All of that is fine but I was just trying to keep within the context of what Stephen originally posted.

But, really, all you have to do is make sure that everything is good condition as far as mounts, u joints, etc. Nissan did a pretty good job of engineering these cars. If all of the compenents are in good working order, there's no 'clunk'. Speedracer, if you want to put solid mounts, etc. on it, do it. It's your car. I could go into all of the reasons, like the ancillary damage that will eventually cause, but, based on your previous responses, I doubt if you would listen. When you say 'you race' that most likely means that you abuse the hell out of a street car which isn't the same thing.

The ECU doesn't run programmed settings as, like I said, it is not a computer. All it does is complete or not complete circuits based on what it gets or doesn't get from the different sensors, switches, etc. It make no adjustments, computations, etc. What you describe could be caused by a bad water temperature sensor or bad connection at the water temp sensor. It's function is to allow the fuel mixture to be richer when the engine is cold. As the temperature rises the resistence in the sensor gradually changes, leaning the mixture and changing the duration of the fuel injection pulse until the engine reaches operating temperature. If that sensor is bad or the connection to it is bad, the fuel mixture will stay rich when the engine is warm and that will cause idling and performance problems. There are other parts of the system that can cause that type of problem but the water temp sensor circuit is the most common. And the reason I asked why you think that your ECU is bad is that it's such a simple device that they seldom go bad. I've seen many people go through the hassle of finding the correct replacement for their particular vehicle, which is not always easy since there were several different ECUs used, only to find out that it wasn't the cause of the problem they were having. I personally have never had a problem with an ECU and I've been around these cars a long time. The same thing goes for the air flow meter. More often than not, ECU and AFM meter problems are cause by people opening them up and tinkering with them based something they read on Atlantic Z or some such site without knowing what they were doing. To me, those are both items that you can leave out of the loop as far as trouble shooting goes as long as they both have clean connections and they are the proper ECU or AFM for the particular car.

You're overthinking it. Just replace it with a stock mount. They last...just not 35 years.

It wouldn't be an L24E That's the 810/RWD Maxima engine. More likely an L24. I might be wrong since it't been awile since I worked on a L24 but I think the 2:00 position tab is different and and can just be unbolted and switched to the other side. You'll have to get the tab from a later engine to put it in the 11:00 position. You need the tab from a L26, L28E, or L24E.

The timing marks are at 11:00 on both my engines. It doesn't have anything to do with AC as one car has non factory air and the the other has factory air. IIRC, the L24 had the tab in the 2:00 position and the L26, L24E, and L28E and all post-73 engines had it at the 11:00 position. Which ever pulley you use has to be clocked to match the timing tab position. They (The Z store) really should sell a pulley for 70-73 and another for 74 amd up.

And you've got an L motor! Good for you. I'm so tired of looking under the hood of a 510 and seeing a KA24 or SR20 etc.

Mine old one still had a Nissan sticker on it too. When unbolted the diff., the mount came apart in two pieces.