Newbie with some general questions
05-11-2004 | 01:08 PM
#1
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Posts: n/a
Newbie with some general questions
Yet another newbie here. I recently bought a 1982 280zx with 102k on it from the original owner. 2.8L NA 5 speed. I have a basic knowledge of mechanics, but I am trying to get "z smart." This is the first foreign car I have owned, but so far I love it. I do have a few questions for the pros though ;-). First I will tell you what I have done so far:
New distributor cap and rotor.
New ignition wires.
New NGK spark plugs.
New fuel filter.
New air filter.
New O2 sensor.
New muffler.
New alternator.
New oil pressure sending unit.
New battery.
Oil change.
New synthetic gear oil in tranny.
Everything on this car is besides the above items and of course tires/brakes is original. Body/interior are in excellent condition. The couple of things that I can't figure out:
Engine seems to miss slightly at idle. There is just a little bump about every 2-3 seconds and the miss can be heard at the tail pipe- it just has a steady hum with an occasional *burp*. I checked all my vacuum lines and I couldn't find any leaks anywhere. I'm thinking maybe timing is off a bit? Idle is at 750rpm. I know the valves haven't been adjusted in a long time...could that be it? Any other suggestions?
When the car is cold, I'm getting a little gear clash going into 2nd. Only 2nd. Once it warms up it shifts fine. I thought maybe the tranny oil was thinning out once it got hot so I drained the old oil out (which was disgusting) and refilled it with Castrol synthetic. It got a little better, but still does it. Ideas?
The speedometer bounces within about 10 MPH of actual speed. It also makes a ticking noise which is proportional to vehicle speed. I removed and inspected both sections of speedo cable which appear to be fine. Is there some kind of adjustment I can make or do I just need to replace the speedo head? Also, the cruise control doesn't work very well, but I think it is due to the speedometer bouncing. Also, the needle does not always reset to zero when I stop. Sometimes it will read 15-20 MPH while it's parked.
Finally, does anyone know what the tiny electric fan under the dash and directly to the left of the glove box is for? The thing was making a loud clattering noise so I just unplugged it. Should I worry about replacing it?
I bought a Chilton manual which I quickly discovered was about as useful as a screen door on a submarine. I know to go with Haynes next time.
I appreciate any advice you can offer. I look forward to hearing from you all.
Thanks. -Collin
New distributor cap and rotor.
New ignition wires.
New NGK spark plugs.
New fuel filter.
New air filter.
New O2 sensor.
New muffler.
New alternator.
New oil pressure sending unit.
New battery.
Oil change.
New synthetic gear oil in tranny.
Everything on this car is besides the above items and of course tires/brakes is original. Body/interior are in excellent condition. The couple of things that I can't figure out:
Engine seems to miss slightly at idle. There is just a little bump about every 2-3 seconds and the miss can be heard at the tail pipe- it just has a steady hum with an occasional *burp*. I checked all my vacuum lines and I couldn't find any leaks anywhere. I'm thinking maybe timing is off a bit? Idle is at 750rpm. I know the valves haven't been adjusted in a long time...could that be it? Any other suggestions?
When the car is cold, I'm getting a little gear clash going into 2nd. Only 2nd. Once it warms up it shifts fine. I thought maybe the tranny oil was thinning out once it got hot so I drained the old oil out (which was disgusting) and refilled it with Castrol synthetic. It got a little better, but still does it. Ideas?
The speedometer bounces within about 10 MPH of actual speed. It also makes a ticking noise which is proportional to vehicle speed. I removed and inspected both sections of speedo cable which appear to be fine. Is there some kind of adjustment I can make or do I just need to replace the speedo head? Also, the cruise control doesn't work very well, but I think it is due to the speedometer bouncing. Also, the needle does not always reset to zero when I stop. Sometimes it will read 15-20 MPH while it's parked.
Finally, does anyone know what the tiny electric fan under the dash and directly to the left of the glove box is for? The thing was making a loud clattering noise so I just unplugged it. Should I worry about replacing it?
I bought a Chilton manual which I quickly discovered was about as useful as a screen door on a submarine. I know to go with Haynes next time.
I appreciate any advice you can offer. I look forward to hearing from you all.
Thanks. -Collin
Last edited by daviscmp; 05-11-2004 at 01:10 PM.
05-11-2004 | 05:52 PM
#3
Guest
Posts: n/a
This post won't be of much help other than to let you know that you're not alone. I also have a 1982 280ZX which when cold is hard to shift into 2nd gear. I also removed the little fan in the dash because it was making a loud squealing noise. If I remember correctly, I took it apart, greased it up and put it back in. I have no clue what it does though. The Haynes manual is really good, specific to 79-83 Zs. I also have the Clymer 79-83 Shop Manual as well. It's been very helpful.
Good luck with your Z.
Good luck with your Z.
05-12-2004 | 08:58 AM
#4
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
I would suggest replacing all six fuel injectors when you can. They go bad from age, even if you don't have a lot of miles on them. That is probably why the engine misses a little at idle. You can try doing the valve clearance, but it may not smooth the engine out. if you can live with the slight missfire, then that's ok too.
If your speedometer stops at 10mph, then the gauge itself is bad. Replace the gauge cluster. (used is fine) Also, there is an adjustment for the reading. After you replace the gauge, if it still reads a bit off, check your speedometer cable cog. At the point where the speedometer cable goes into the side of the transmission it connects to a small plastic gear. This gear determines how fast the speedometer reads and needs to cooinside with the gear ratio of your differential. It has nothing to do with what transmission you have as it only reads the final output shaft speed of the transmission. Your car may have had the differential swapped with another Z of a different gear ratio. If so, you'll have to do some figuring out on what ratio you have and what cog you need.
Ah yes, the 2nd gear grind. Your syncros are starting to go out and 2nd gear is always the first to go. Mine did that at 130,000 miles when I bought the car. Now, at 218,000 my transmission finally died. At about 215K 2nd gear wouldn't even stay in gear then the problem quickly spread to 3rd and 1st. What you need to do is shift smoothly and save money for a transmission rebuild, but you've probably still got a lot of life left in your transmission. By no means did I shift easy on my car. i beat that transmission into the ground from 130K - 218K
As for the little fan behind the dash, ya, mine made all kinds of noise too. I found it unplugged when I got my car. So I plugged it in and found out why it was unplugged!
It sucks in air from a little round vent in the dash and reads the temperature of it. It works with your auto temperature controls in the car. those controls usually always stop working a few years after the car is brand new. Most people find manual fan controls and replace the auto climate controls with those. Just leave the little fan behind the dash unplugged.
If your speedometer stops at 10mph, then the gauge itself is bad. Replace the gauge cluster. (used is fine) Also, there is an adjustment for the reading. After you replace the gauge, if it still reads a bit off, check your speedometer cable cog. At the point where the speedometer cable goes into the side of the transmission it connects to a small plastic gear. This gear determines how fast the speedometer reads and needs to cooinside with the gear ratio of your differential. It has nothing to do with what transmission you have as it only reads the final output shaft speed of the transmission. Your car may have had the differential swapped with another Z of a different gear ratio. If so, you'll have to do some figuring out on what ratio you have and what cog you need.
Ah yes, the 2nd gear grind. Your syncros are starting to go out and 2nd gear is always the first to go. Mine did that at 130,000 miles when I bought the car. Now, at 218,000 my transmission finally died. At about 215K 2nd gear wouldn't even stay in gear then the problem quickly spread to 3rd and 1st. What you need to do is shift smoothly and save money for a transmission rebuild, but you've probably still got a lot of life left in your transmission. By no means did I shift easy on my car. i beat that transmission into the ground from 130K - 218K
As for the little fan behind the dash, ya, mine made all kinds of noise too. I found it unplugged when I got my car. So I plugged it in and found out why it was unplugged!
It sucks in air from a little round vent in the dash and reads the temperature of it. It works with your auto temperature controls in the car. those controls usually always stop working a few years after the car is brand new. Most people find manual fan controls and replace the auto climate controls with those. Just leave the little fan behind the dash unplugged.
05-13-2004 | 09:04 AM
#5
Guest
Posts: n/a
Thanks for the advice so far.
What other symptoms would I see if the injectors were going bad?
It doesn't always stop at 10 MPH. It does go to zero, but sometimes it hangs up between 10-20 when I stop. Does that make a difference?
Ballpark, what should I expect to pay for a rebuild? I would of course do the clutch at the same time. I checked around here (I'm out in the middle of nowhere) and the only place that would even work on my z said that they wouldn't rebuild the tranny I've got, but they would swap it if I found a used one. I would really like to keep the one I have.
Thanks again all.
I would suggest replacing all six fuel injectors when you can. They go bad from age, even if you don't have a lot of miles on them. That is probably why the engine misses a little at idle.
If your speedometer stops at 10mph, then the gauge itself is bad.
What you need to do is shift smoothly and save money for a transmission rebuild,
Thanks again all.
05-13-2004 | 09:55 AM
#6
The Evil Twin
Joined: Mar 2001
Posts: 9,296
From: Seattle, WA
Other symptoms of bad injectors is poor fuel economy, rough idle, lack of torque, rough idle... and misfirs at idle and while accelerating.
The speedometer should always drop to zero. It is not electric. Weather the car is on or off, if you're not moving it should fall smoothly to zero. The cable spins to bring it up slowly, and not spinning the cable should let the return spring bring the needle down to zero. If it ever get stuck, then the guauge is bad.
A transmission rebuild should cost as little as $200 but maybe $300-350. You might be able to find a really good low mile transmission for $200 but you live in the middle of nowhere so that'll be hard. I would say yours if fairly low miles anyway. Sounds like they all start going bad at 100K miles. It is possible to replace the syncros yourself, but I've never done it. I'll probably try in the future.
The speedometer should always drop to zero. It is not electric. Weather the car is on or off, if you're not moving it should fall smoothly to zero. The cable spins to bring it up slowly, and not spinning the cable should let the return spring bring the needle down to zero. If it ever get stuck, then the guauge is bad.
A transmission rebuild should cost as little as $200 but maybe $300-350. You might be able to find a really good low mile transmission for $200 but you live in the middle of nowhere so that'll be hard. I would say yours if fairly low miles anyway. Sounds like they all start going bad at 100K miles. It is possible to replace the syncros yourself, but I've never done it. I'll probably try in the future.
05-13-2004 | 11:05 PM
#7
Registered User
Joined: Jul 2003
Posts: 532
From: Houston Tx. Cleveland Tx. New Caney Tx. and every other Tx.
I wouldn't replace your injectors just yet man.
you discrib the miss as not a great problem, sounds like to me you should run down to the auto parts place and get a bottle of see foam they will know what your talking about, tell them it is injecter cleaner. that stuff is probably some of the best stuff on the market after using that stuff if the injectors don't work properly after a long period of time then I would check into some new injectors. Remember see foam.
you discrib the miss as not a great problem, sounds like to me you should run down to the auto parts place and get a bottle of see foam they will know what your talking about, tell them it is injecter cleaner. that stuff is probably some of the best stuff on the market after using that stuff if the injectors don't work properly after a long period of time then I would check into some new injectors. Remember see foam.
05-16-2004 | 01:20 AM
#9
Registered User
Joined: Jul 2003
Posts: 532
From: Houston Tx. Cleveland Tx. New Caney Tx. and every other Tx.
I hardly think that an exoust leak or biger diameter pipes will caus the care not to fire on time, or for that matter effect the enjecters, inless that is of course you mean it is back-fireing. In that case the manafold probably got to hot blew the gasget, and warped the manefold. wich I have herd this happening often on these cars. not likely that this is the problem thogh.
06-02-2004 | 10:02 AM
#10
Guest
Posts: n/a
Thanks for all the advice guys. I have made some good progress. First, I adjusted the valve lash (11 of 12 were off). Eatmydust, thanks for the tip on the sea foam, it worked great. The only thing that sucked was that I added it AFTER I set the valve lash so I had to set it again after all the gunk was disolved. Oh well. Live and learn. I found two of the plastic spacers between the fuel injectors and the head that were cracked and replaced them (also replaced all of the o-rings). That seemed to help some too. I do have a small exhaust leak at the manifold, but it is going to be a PIA to fix. Also, I was able to fix the speedo. After I took it out of the dash, I found that the plug where the cable goes in had loosened up and canted to one side. There was no nut to tighten so i just set it in straight and put a couple drops of super glue on it to hold it in place. Works like a charm now. Thanks again guys.
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