Arne

OK, here's a new one on me. The tach in my early '71 240Z (4 wire) suddenly this afternoon started to peg the needle at 8000 RPM any time the key is turned to the Run position, whether the engine is running or not. I suspect a problem with the tach itself, not the wiring as the ignition appears to be working fine, since the car starts and runs normally. Any thoughts?

DOT 5 is NOT compatible! Going to DOT 5 would require a complete rebuild of the entire brake system - every single rubber bit replaced, and the metal lines flushed with denatured alcohol. Dot 3 is still easily available, DOT 4 will work as well. There's no real benefit to DOT 4 though, so DOT 3 (which is generally cheaper) will be fine. Castrol is fine, as mineral oil goes. Any name brand ATF should work fine.

That makes it considerably more difficult to make work well. My car had the injection from an '83 280ZX on it when I bought it. I found that trying to get it all to work well with the early car's wiring and fuel plumbing was hard to do, it seemed like one cobbled-up system connecting to another cobbled-up sub-system connected to...Unlike carbs, the factory injection system is not typically a stand-alone unit. The entire fuel system has to be matched and compatible. Certainly the best way to do it would be to use the entire system from a single car, but the hidden stuff is what bites you in the end. As an example, the entire engine/injection in my car was from an '83 280ZX. They plopped the engine in, welded the stock exhaust up to the ZX downpipe, connected some of the wires, installed the ZX fuel pump and thought it was done. But the temperature gauge didn't work, because the ZX sender was different to send temperature data to the injection computer as well. There were left-over wires hanging here and there with nothing on the early harness to connect them to. Other places the wires on the injection harness were just snipped off. ("Were those wires important? What did they do?") They kept the factory fuel piping for both the feed and the return - the feed was a bit small and caused the pump to work harder than it should, and the return line dumps into the tank in a different place than the injection return and made horrible noises in the tank from the returned fuel spraying back into the tank under pressure. And the oxygen sensor didn't work well, apparently due to the flutuations in the voltage supplied through the early car's wiring. The injector flow rates were unstable, apparently due to the pump working so hard. All in all, my car is SO much better with the carbs back on it again. I'm a fairly experienced mechanic, and I don't think I'd want to try to do that swap myself due to the work it would take to do it right. The 240Z SU carbs are simple in comparison, and perform just as well if they are properly tuned. In summary, I went back to the carbs and couldn't be happier. The wiring and fuel piping in the early cars is just not quite up to the injection, in my opinion. I'm certain that there are plenty of people who will tell you they've done it, but I have seen the result in my car and would never try again. If you really want a Z with injection, I'd recommend buying a 280Z instead.

Depends on your definition of a '70. The automatics began production in 9/70. Some of them were titled as '70s, most were probably titled as '71s.

I think you're right, Stephen. I was thinking MGB when I looked at that one, but I haven't had a B manifold in my hands for over 10 years.

I don't think those are all three from the same car. The two outer ones look like the typical Cannon dual Weber conversion, they bolt to the existing manifolds. The inner one is from something else.

It's done all the time. My '71 has one in it now. Simplest is to use the carbs and such from the L24. The largest "difficulty" is in the exhaust manifold, most of the L28s have round exhaust ports and so you'll need a different manifold or header. Pretty much everything else is the same. (unless you want to use the injection, which takes a lot more work.)

Early production (Series 1 cars) ended sometime during January '71. You can find both early and late '71s with 1/71 build dates.

Actually, that's a late '71 with the wrong hubcaps. That said, it looks like a really good car.

I use Redline in most everything that's not a motor, and either Mobil 1 or Castrol Syntec in the motors.

Wrong. The P90 has square ports, that's part of what makes it good. And I believe you can put the external oiler on any L-series head, as long as you use an externally oiled cam. Sounds to me as though it's time you do some homework before you spend any money.

Without knowing the year it's hard to say. The wiring varies from year to year.

Go to the dealer and buy one? http://www.courtesyparts.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=CP&Product_Code=240Z-HORN

No opinion. As Jon noted, we can't see the water passages. Plus I'm still of the opinion that for a street engine, the difference between an E31 and say... an E88 or N42 probably isn't noticeable.I don't think I'd want to pay all that much for it, regardless.

There's one on eBay now... http://cgi.ebay.com/ebaymotors/Datsun-Nissan-240Z-E31-Aluminum-head-w-o-h-cam-1970s_W0QQcmdZViewItemQQcategoryZ33617QQihZ017QQitemZ270011001573QQrdZ1QQsspagenameZWDVW

Update - By the time you get to a 4/71 build date, the fusebox changes from long to short pigtail. The tail-light wiring is also slightly different by that point.I still recommend one of two courses on this topic - either find the correct harness(es) for your car's build date, or change it all. I still have some reservations about the wiring on my car, and will save the entire wiring system out of the 4/71 parts car I recently got, to install later if it seems appropriate. (Probably when I strip it for rust and paint.)

I'm watching those already. Any bets whether they go for at least $300?

Dear Lord, please let someone tool up for a reproduction of the chrome center trim for a 240Z tail light. That way, those of us who want nice taillights for our non-trailer-queens will be able to afford them. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=110008839825&ih=001&sspagename=STRK%3AMEWA%3AIT

Jenny, while you do live in an area where there are more Z's available than in many parts of the country, finding what you want will be difficult. First, there aren't a whole lot of '70-71 240Z left these days, what with rust, accidents and such. Of those, blue is/was uncommon, and with a blue interior decidedly so. Add the final criteria that you need one ready to drive, and it's going to be hard. My recommendation would be to be open to a little wider range of cars. Maybe consider '72-73 240Zs as well, and since the blue upholstery can still be purchased, don't rule out a blue car with black or white. In fact, there was a really nice one owner '73 for sale at the Datsun gathering in Canby last month - it was blue, well maintained and ready to drive. I think it was a black interior, but that could be dealt with. As I recall it, he was asking $10k for it. Maybe someone got his name?

Lots of places still have them or can get them. The major brands that are still available are KYB, Tokico (both normal and adjustable versions), Monroe Sens-a-trac, and Koni. All are gas-filled except the Konis. The KYBs and Tokicos can be ordered from MSA or Black Dragon, among others. If KYBs are what you decide on, you can get them from this guy on eBay for $140 delivered. He almost always has a set offered. One thing to note - most people notice that gas struts with factory springs tends to raise the ride height some.

I did the one out of my parts car today. It's been running for over two and a half hours now, a new record for me and Z clocks! I took some pictures when I did it, so I thought I'd add them as visual aides. The file names are descriptive.

Does the manifold only have two studs per carb? Any pictures?

I agree with this in theory, and actually planned to use a stock manifold on my car. However - this is only great advice if you already have a stock manifold that it is really good shape.My car had (and still has, for now) an '83 L28 in it. P79 head with round ports. I'm going back to a stock L24 which will have square ports. So the 280ZX cast manifold won't work. Which prompted me to begin looking for a stock 240Z manifold. And I found that good ones are darn hard to find. First, almost all of them have broken and rusted flange studs. Every one I saw needed them to be drilled out and tapped. Second, many of them still have broken and rusted air injection rails still attached. And as with the flange studs, they are typically rusted solid. Drilling those out is a much more difficult job than the flange studs. Lastly, how many of us have seen L-series engines with one or both of the exhaust studs at the front and/or rear of the head broken? This apparently happens because over a period of many years the cast manifolds warp. They get a pronounced bow to them and exert downwards pressure on the end studs. Eventually the stud breaks off. Many of the used cast iron manifolds you might come across will be warped in this way. Place a straight-edge along the bottom of the ports and you'll see what I mean. So after working on all this, drilling, tapping and such on a used manifold that is less warped than many (but still noticeably warped), I'm going to cut my losses and use a header instead. Not for performance so much as to save myself a whole lot of time and effort.

I'm pretty sure the even the early cars came with these originally. My '71 has them, as does the '71 parts car I bought recently. You've pretty much figured it out, the center slides over the tad on the pad backing plate, and the ends go under the pins. This is the only picture I could find in a hurry, sorry it's not more clear.

Any of the three will work fine, if set up and adjusted correctly. My preference for a stock L24 would also be the round-top SUs. But to buy them from ZTherapy, you'll need a set to exchange, as ZT's are rebuilt, not new. So you may want to start shopping for a used set, first. Used ones show up on eBay frequently. I have two pairs now, as the parts car I recently bought still has a set, but I'm not ready to sell them until I find out if they're any good.