Pilgrim

The car: 1983 280ZX turbo, about 115K miles. Body/motor condition: excellent. Last weekend I changed the water pump (1st time), and in doing so discovered that the plastic fan blades on my '83 ZXT have a couple of significant cracks. They aren't going to break this week, but I don't need to keep driving it for very long before fixing this. The question: replace the plastic fan blades, or change to electric fan cooling? I don't really mind the characteristic Z fan noise, but I could live without it. Fan blades appear to be available used on Ebay in the $40 range, and installing a set of replacement blades probably could be done in an hour or a bit more. OTOH, there is a fair amount of info out there on changing to an electric fan. I might gain a couple of net HP, but that's not a deciding factor. I could go new with a variety of options ranging from twin 10" fans to a single larger one, or I could go used, with a fan taken from a Taurus. If I go with new fans the cost will start at over $100 and could go to $250 or more depending on the kit I buy. If I go used, I can get a Taurus fan inexpensively but also will need to arrange power connections (not a big deal) and create a thermostat control setup. I should mention that the cooling on this ZX is great in most weather, but I've been trying to get the AC booster fan to work for two years with no luck, and in 90+ weather in stop-and-go traffic I need to kill the AC or it will overheat. Without AC running, no heating problems. (I am very frustrated with that AC booster fan.) I welcome a discussion of the pros and cons of making a switch.

Feel free to educate me - but I'm not aware of any advantages of head studs. The factory used bolts, and in 30+ years of working on cars I've never found a reason to use anything else. I'm not a racer and there's only one car I've owned that has required removing the head more than once. What would be a reason TO use head studs?

I've never heard of hed bolts having a mileage rating. That's a new one on me. What's the authority or reference behind that idea? And I wouldn't remove any and re-insert and re-tighten them...that's asking for bolt or gasket trouble. If I needed head bolts, I'd buy Nissan - period. Of all the places to cheap out, head bolts would be the very last I'd choose.

I have a basic rule - figure out the simplest thing that can cause the problem, and check it first. I'm wondering if you had the dash out and unplugged the harnesses on the right side of the dash. Could it be that one of them didn't get re-connected? It's worth dropping the kick panel and having a look. Don't forget the unit right behind the glove box.

If you feel compelled to pursue it, another Z-owner was nice enough to send me a series of emails on doing the speedo modification. I could forward them.

It's a function of the way the speedo is built - there's a mechanical interface in the speedo. You can't change it without going to the '79 speedo which reads higher - but to change the mechanism, you must pull the dash, remove the speedo and do some surgery on it. I bought a '79 speedo and was about to do this, but decided to just re-install my '83 speedo. I still have the '79 speedo on the shelf (yes, it's available). Just an aside - I don't know any place where the speed limit is over 80 so I'm not sure why it matters (nudge, nudge, wink, wink, say no more). On the freeway between here and Denver (75 MPH limit) I set it at 81 and everything works fine, although due to the age of the unit it deviates from the set speed more than I'd like.

Unless you have a battery leak, I'm not sure why progression of rust in the engine compartment would be a problem. if you want to de-rust the engine compartment, you'll have to do it regardless of whether you move the battery. My vote is to clean it up, have a welding shop replace the old platform, get another plastic battery tray to replace the original, and leave the battery where it is. It's pretty convenient there. I'd much rather have a battery outside the passenger compartment!

There are plastic clips used to mount those. IIRC they push into the seal around the glass and two ears stick up - the molding clicks onto them. it can be difficult to get them to click in. I believe that Charlie at Zed Findings can get the clips.

Here's my 1983 280ZX Turbo. I've owned it since 1990 and it's bone stock aside from the radio and Tokico shocks.

Good idea! getting power direct to the device always tells you whether the device is the problem or if it's something before it. Will do.

That would probably help on the driver's side...and it's a good reminder. On Audis, that kind of lubrication is a required item every couple of years. I hadn't thought about it on the ZX. On the passenger side there's clearly a problem with getting power to the motor. Whether this is in the switches, a loose connection or broken wire at the motor, poor ground at the motor, or internal failure of the motor isn't clear to me yet.

Car: 1983 280ZX Turbo. For some time, the passenger side window has gone down nicely but sometimes requires dozens of attempts to raise it - repeated applications of the switch on either driver or passenger door have little effect until one "catches". All of a sudden last weekend, the driver's side window is sometimes slow to come up, although it usually kicks into regular speed part-way up. All I need is to have it get stuck in the down position!!! Anyone BTDT with these problems? I'm thinking it's something about the motors - perhaps grounding. I do have a spare set of driver's side window switched from Ebay. Thanks!

Sounds like you're on the right track - I support the idea of doing all that's possible to diagnose a problem via sensors, etc. before tackling a major mechanical task. It just makes sense to eliminate other possibilities before taking on a 10+ hour job. It may indeed be coolant that's causing white smoke but without a demonstrated head gasket leak, I'd put it at less than a 50% probability. Not impossible, just less probable. If the coolant level is dropping or there's other evidence of a leak, probability increases.

So why are you starting multiple threads about the same problem - and still fixated on the head gasket?? And please note that the fuel pressure regulator will click rhythmically as it does its job..that has fooled people (including me) in the past).

Given the 120 PSI compression test (low but probably adequate) there is no reason to think you have a head gasket problem. I'm with the others in thinking it's a sensor that's giving the computer bad info, and as a result it's running incredibly rich.

Hard to tell, but I'm far from convinced it's an oil problem. I would not be hunting a head at this point, I'd be looking at the fuel system and its regulation.

Sounds to me like the FI is running extremely rich. I don't know the computer system in this car or how much of a system there is...but it sounds like something is confusing the system. That could easily point to a bad sensor. #1 thing I would do is find a factory service manual and start looking for tests I could run based on its directions. I'd run a wet/dry compression test on it (easy to do) just to set a baseline for the compression. I don't have an explanation for having oil on all the plugs - but I'm not convinced it's oil. I'm wondering if they're actually wet with fuel. Oil makes no sense to me with the minimal information you have at this point, but a compression test would tell you whether there is a head leakage issue, or perhaps very bad rings. I'm wondering if the smoke you see is blue or black. Black is fuel, not oil. Blue is oil. My advice: DO NOT start changing parts!!!!!!!!!!!!! Don't worry about the head or changing it until you have a factory shop manual and have done a LOT more testing. the most challenging part of working on a car isn't changing parts, it's making a good diagnosis. Get a diagnosis FIRST!!!!!!!!! One thought: I once owned a '66 GTO which still had good compression but it had been gotten so hot that the oil rings on the pistons lost their temper and stopped working. A compression test wouldn't show that failure, but oil consumption would. That GTO burned a quart in 50 miles. This is extremely unlikely to have happened to the Z.

Well, after cleaning and using DeoxIT on the throttle position sensor, I've driven the car for two days without any sputtering or hesitation. Once again, that silly little TPS turns out to be the answer to a seemingly major problem. But I'm grateful not to be out $150 for a fuel pump. Caig Labs sells DeoxIT and other great contact cleaning and preserving chemicals like ProGold. GREAT stuff, not cheap, but worth every penny. Keep some around.

George, I'll double-check, but on the turbo model I didn't think there was such a module. (I may not have made it very obvious in my original post listing it as a "ZXT", but it's a turbo.) I'll research it today. I know there's no ignition module on the side of the ditributor like there is on the NA models, but now that I've re-read your posts, I think you're referring to a different part. Yesterday I checked fuel pressure and it's 60 PSI, so there's no problem there. However, the throttle position switch had badly corroded connectors and I treated them with DeOxit to cut through that. Took the car out and drove it, and it worked great. I'm very suspicious, but I'm thinking it COULD have been corroded contacts on the TPS. I know that if you get that TPS wet, your ignition will cut ott about 3K RPM. More later..... Later: Can't find any reference to an ignition coil module, but there is a "Power Transistor" mounted on the side of the bracket that holds the coil. Is that what you're referring to? And BTW - took the Z out for another run after cleaning the TPS contacts and no stumbling or faltering at high revs.

Computoman, I don't think there's any point in replacing the coil until you have eliminated gas as the problem. Your symptoms don't sound like electrical issues to me. I had an '82 280ZX that would die suddenly - it was the ignition module on the side of the distrib that got hot and failed - typical problem. Easy to diagnose, too. Carry a thermos of ice water - when the engine dies, coast to the shoulder, pop the hood, douse the ignition module on the dist side with icewater. If you can fire it right up after this, you know hte problem. At any rate, I borrowed a fuel pressure gauge from a mechanic friend and will test the pump's output this weekend. Bet I find there's not much pressure coming from the pump.

That break-in info seems somewhat dated. I wonder how many drivers under 40 years old even know that non-detergent oil exists? And some of the links at the bottom are no longer good.

I've had the problem with the TPS getting wet when washing the motor - boy, will THAT kill your revs at @3500. But I think it's fuel delivery - just haven't had a chance to get under it yet.

I first did this at age 18. I learned that if you keep parts separate and labeled, and follow the instructions in a good manual, the rest is just grunt work. Hints: - Check all bearing clearances with plasti-gage - Lube all rod, crank and other bearings with Lubriplate grease when assembling (so you have some lube in place while oil pressure is pumping up) - Don't force ANYthing - Mark all main bearing caps and conn rods so you know which way they face and which sides match up. That's what comes to me at the moment...

Here's another reason to be concerned: at highway speeds, fans can actually block or restrict air flow through the radiator, causing heating. This can be a factor even with a full size electric fan, especially if it can't turn fast enough to expedite air flow at highway speed. Adding a number of small fans would mean a lot more area (in the frames and area blocked by the fan blades)where there is limited air flow - which seems to me a matter for concern. Food for thought. You might also see if you can find a pair of moderate size (side by side) radiator fans from an early 90's Audi 90. They're quite compact and move a lot of air, and they come mounted in a frame which might be handy. There is also a website (a search might find it) describing how to use the electric radiator fan from a Ford Taurus as a general purpose radiator fan. It has been used in BMWs.

You may have a cumulative air flow of X, but with the total flow in CFM broken up and distributed across many small surface areas, the flow across any one area may not be sufficient. I'm skeptical.