Datsun Z questions

[dsp]

Hello everyone, I am new to the forum and datsun's in general. I was hoping you all could help me out. I have wanted one of these cars for quite a few years now and finally have enough spare cash to buy one in decent condition. My question is that most all of the z's for sale within 2-3 days drive of me are 280Z/ZX's. My question is how reliable are the fuel injection systems on these cars? I would like to use the car as a daily driver from spring to fall and need something that is not going to require constant attention. I am more familiar with carbs since I drive older cars and trucks. I wouldn't mind a fuel injected car as long as they are not prone to constant problems. I am used to scouring older cars for rust, but what are some other things I should make sure to check on the Z's, especially the 280 Z/ZX's? Any and all information you guys can provide will be greatly appreciated.

Dan

[Gary in NJ]

Opinions will vary on this subject. In my opinion, the SU carbs are far more reliable and easier to maintain then the primitive and somewhat finicky Bosch L-Jetronic fuel injection found on the 280Z.

I've been on the hunt for a 280Z. When I find the right car, one of my first modifications will be to replace the FI with SU's. I can probably sell the FI system for the cost of freshly rebuilt SU's.

Others will think I'm crazy, but I just ENJOY working on SU carbs. Sorting out FI problems is a PIA.

[FastWoman]

My question is how reliable are the fuel injection systems on these cars?

ROFL

OK, seriously, the EFI systems on these cars can be very reliable, but I think it would be the very rare 280Z(X) out there that would be in properly running condition. In fact I don't think there are many cars more than 10 years old that don't have at least a few engine problems. People don't realize these engines have problems, because they "run good." However, they don't run like new, and that's because of an accumulation of small mechanical problems.

So if you get a 280, it will run for you in the manner in which you bought it. It will run worse over time, with no attention given to it. If you want it to run well, you'll have to find and fix several little problems. The thing about these systems is that they have no diagnostic capabilities, so it will be up to you to go through the system and diagnose it yourself. The factory service manual is quite good and is a big help in this regard. There's also a "fuel injection bible" that's even a better resource.

Most problems amount to vacuum leaks (rotten hoses), bad electrical connections, old injectors (needing replacement), funky air flow meters (that need recalibration and cleaning), and sometimes even drift of the engine's "computer" (or ECU), which requires a "field fix" of insertion of a resistor in series with the coolant temp sensor. People here will help you with that.

Once you get it running right, it will be very reliable.

[Ralphy]

ROFL

OK, seriously, the EFI systems on these cars can be very reliable, but I think it would be the very rare 280Z(X) out there that would be in properly running condition. In fact I don't think there are many cars more than 10 years old that don't have at least a few engine problems. People don't realize these engines have problems, because they "run good." However, they don't run like new, and that's because of an accumulation of small mechanical problems.

So if you get a 280, it will run for you in the manner in which you bought it. It will run worse over time, with no attention given to it. If you want it to run well, you'll have to find and fix several little problems. The thing about these systems is that they have no diagnostic capabilities, so it will be up to you to go through the system and diagnose it yourself. The factory service manual is quite good and is a big help in this regard. There's also a "fuel injection bible" that's even a better resource.

Most problems amount to vacuum leaks (rotten hoses), bad electrical connections, old injectors (needing replacement), funky air flow meters (that need recalibration and cleaning), and sometimes even drift of the engine's "computer" (or ECU), which requires a "field fix" of insertion of a resistor in series with the coolant temp sensor. People here will help you with that.

Once you get it running right, it will be very reliable.

Very well put. If you are thinking of getting an older car like this just expect to have something.

[sblake01]

Both my 78 280Z and my 79 810 coupe must have been in that 'very rare' catagory then because they both ran how they were designed to run, never failed a smog check, got the advertised gas mileage (maybe even a little better), started, stopped, etc. like they were designed to without any non factory modifications. They were both purchased from the original owner and were well cared for before I got them. Maybe I was just lucky....

Edited February 10, 2011 by sblake01

[Walter Moore]

Lucky? Steve, really...

More likely you are:

A. sufficiently knowledgeable to be able to maintain your own car

(you are a retired Nissan mechanic aren't you? You are certainly a wonderful source of information on the intricacies of the fuel injection and air conditioning systems on these cars.)

B. live in a state (California) where there are still a large number of good condition Datsuns available

(Both because of the climate, and the mandatory air pollution testing that cars there must endure.)

C. apparently were able to find one-owner cars (which has to help considerably)

Many of us are stuck with rusty 30-40 year old cast-offs and are luck if we find one in rebuild-able condition.

Back on subject, I personally prefer fuel injection to carburetors, when it is working properly. However when dealing with any 30+ year old car there are going to be issues with the old electronics and particularly the old connectors. In places where we have wide temperature extremes and high humidity you need to be wary of the electrical connections and wiring on any old car. The bad news is that wiring and connectors are at the heart of any ELECTRONIC fuel injection system.

[esmit208]

DSP

I drove(and stil have) a 1981 280ZX for over 300K and never had any difficulty with the fuel injection. The car had over 125K when I bought it. The air flow meter had to be replaced once but that is not an uncommon replacement also it is not a frequent replacement. If you find a ZX I am pretty sure you will not have BUYERS REMORSE but plan to put some money into it to maintain it. These cars are NOT generally LEMONS, even one that has been beat on. Good Luck in your search. I would try to find an Arizona car. They tend to have fewer cancer issues

[Montezuma]

My 78 had/has (had because the kid who got it wreaked it) 376,000 on the motor and never any fuel injection problems. Most dependable car ever.

[sblake01]

I was being facetious. I know of many other 280Z(X)'s as well as other 10+ year old cars that run like new.

[zpizzaman20]

The key to the fuel injection is keep up with it.

Replace the vacuum lines, get new injectors, clean the connectors, etc.

Just like anything else if it is neglected it will drive you nuts.

[FastWoman]

Well, I suppose "rare" was too strong a word for me to use. I would say that the lion's share of old cars have at least a few problems that may or may not "seriously" compromise the functioning of the car. Evidence of this is that many people (including many mechanics) don't expect an old engine to run as well as a new engine. If an old engine is properly maintained and free of mechanical problems, it will run every bit as reliably as a new engine, although it might burn more oil from wear. I've not yet bought a car that couldn't be restored from the ubiquitous "runs good" condition to a "runs like new" condition.

I've bought many old cars in my lifetime that have been in ostensibly good ("runs good" to "runs great") condition. I have yet to see one that didn't have a single problem. The closest might be this little Miata we just bought -- purchased above book from a Miata enthusiast who restores the things as a hobby. The engine functions perfectly, as far as I can tell, but the radiator and coolant hoses are frail and require replacement, and there is a section of oxygen sensor wiring whose shielding was burnt on the exhaust. Also the convertible top leaks, and clutch hydraulic fluid is LONG overdue for a flush (which admittedly aren't engine issues). I'm sure I'll find other problems as I drive the car more.

To the OP: I doubt there is much reliability difference between the late Zs and early ZXs. However, there seem to be fewer ZX owners out there who are able to advise you about your engine problems. ZX people often come to the Z forum hoping we can help them. We can often toss out a few ideas, but few of us really know anything about the 280ZX.

With regard to the 280Z models: The '75 has the prettiest engine, IMO. They introduced a much needed backfire relief valve in the AFM in '76, but it's a similar car. The '77 and '78 models offered a few more refinements, including much, much improved heat shielding (which improves reliability but not appearance) and a bit of hood venting. They also introduced a completely moronic space saver spare system that actually wastes more space than it saves.

Then the ZX models introduced forced air venting of the intake system, greatly improving the longevity of those parts and decreasing the vapor locking problem common to 280Zs.

Also, every year from the '69 240 and into the ZXs got heavier and more elaborate. The earlier models are better for racing around twisty curves, and the later models are better GT sorts of machines -- more comfortable -- better daily drivers.

Edited February 11, 2011 by FastWoman

[IdahoKidd]

My 77 runs flawlessly and I'd drive it anywhere at anytime. When I got it, the PO had really messed up the installation of the newly rebuilt motor (that is what led to this board) and once it was fixed (wiring issues), it is great. Not in a lifetime would I change out the fuel injection for the SU's. (I bought a 240 with SU's). Look at as many as you can, buy the best one you can afford. Money spent now is pennies on the dollar for money to be spent later on. There is also a difference in the cars themselves (280 and 280zx). The zx is a little more plush, and a lot more unattractive.