Hello fellow Z Enthusiasts, I've been here for quite some time using this site as a "guide" for my 83' Maxima, though (and I can't express how lucky I really am) I've been "gifted" my aunts 1979 280zx, so It's time to buckle down and really start getting work done.

This old Z was destined to a life in a junkyard rotting away , until after 10 years of seeing the car just sitting, I finally knew enough about cars to get my aunt to say, "Its yours, Fix it". My aunt drove the car daily until 6 years ago when it started having problems that eventually led to its life of rusting in the driveway for years. I initially knew absolutely nothing about Z cars, as I grew up working on classic v8's. My dad and I built my '70 Mustang and now we're building his '53 Oldsmobile (We're the only two in our entire family that actually enjoys working on these old classics and putting them back on the road where they belong.) Thankfully, Sites like these exist, and I was able to find out what the problem with the Z was and get it running.

The reason my Aunt parked this Ol' Gal was because after 10 minutes of driving the car would shut off like you turned off the key (which later I found out was because of the Ignition Control Module). After pushing the car to my Grandma's house and finally getting a good look at the car, we replaced the ICM and tried starting the car (and as it usually goes with fixing cars, one problem was solved and another popped up). Turns out the fuel injectors were completely plugged. After 3 hours of pulling, wrenching, slipping, knuckle-busting, and freezing due to 20 degree weather, I finally managed to pull the injectors. After getting them home, I left them soaking in cleaner over night and then the task of putting them back on began (Just as much "Fun" as it was taking them off...). Cleaned out 5 gallons of old gas (If you could even call it "Gas" anymore, it looked more like Iced Tea 'cause it was nothing but varnish).

Then the moment of truth: Will it start?

No, no it will not. Turns out, the fuel pump flopped out, and $114 later, it was ready to test again. Replaced the battery (The original was so bad, after a full charge you could count to 10 and it would go from 12.45 to 0 before you reached 5). Replaced the battery and was going to try it again, when one of the cables that control the ignition decided to catch on fire. After the initial shock of nearly burning my grandmas garage and the car down, I found why it shorted out in the first place. One of the wires became grounded when my father sprayed contact cleaner on the wires, it wasn't dry yet and it shorted out. Replaced all the connections for the ignition box (its the one under the hood near the front, passenger side, behind the relay box). Tried again, Cranked and cranked, and it still wouldn't start.

After 6 days of this, I was loosing my mind trying to get it started, and was about to give up when I decided, "I guess it wont hurt to try this" and held the gas pedal down while cranking. THAT got it (I know I should have tried this earlier, but I was by myself most of the time, and not knowing how the engine would react and not wanting to catch something on fire again) Well, sure enough it started, but ran poor. revved the engine to 3000rpm and it wouldn't go passed 3200, until after 1 minute of holding the pedal down trying to clean the injectors out and get it running correctly, it shot to 6000rpm and after that it revved like a dream, no issue what-so-ever.

Now that the engine ran, the big moment of truth began: Will it drive?

The answer; Sort-Of.
With my grandma out watching, and having the phone on standby if it decided to explode and me with a fire extinguisher (just incase), The car drove around the block without issues, But was a DOG driving. Little to no power. The engine, when running at 120 degrees, would idle at 1000rpm, but didn't seem to like pressing the gas pedal. I let the car sit for 2 weeks, and went back today to see if I could get it driving correctly, though now the problems back worse then before. After starting the car, It revved great without hesitation to 6000rpm, but when you put it in drive, the rpm's drop from 1000 to 500-600 (constantly sounds like its wanting to die). I drove it around the block hoping it would help, but it wouldn't go past 3000rpm, and pressing the gas to the floor did nothing (popping and sputtering). Now I'm fairly certain it cant be timing, as she did nothing to the timing when my aunt parked it, and its been left untouched since it was first parked.

I parked the car back in the garage and let the car idle. I noticed that leaving the car idling at 1000, after about 20 seconds the car would drop rpms then pick back up. While holding the throttle down to 2000rpms, the engine would drop rpms by itself, going from 2000 to 1000, then would try pulling itself back to 2000, all without me letting my hand off the throttle. After calling my father, he told me to take the air filter out and try starting the car. It started and idled at a healthy 1000rpm, and while I didn't think it would have that big of an effect, after telling me to give it gas I found it wouldn't even go past 1000rpm, it was just sitting there. We ordered a new Air Filter, should be in Tuesday evening and I'll post what it does after we put it in.

My main question now is, could the rpm problem I'm having really be because of the air filter?

Thanks again everyone'll Heres a video I took when I first got it started, It'll give you an idea on what I'm dealing with.

 

I am going to take a stab at this, only because the way it sounds in the video. When it is running, try unplugging one injector at a time, and see if you notice a difference. This is exactly the way mine sounded with bad injectors. Give it a try!

To edit, do the same with the spark plug wires and see if one of the cylinders is not firing right, and if you haven't done so, replace the plugs, run it for a bit, and pull them, I am sure you know but this will tell you what each cylinder is doing. My injector problem was that it was stuck open, so it was flooding the cylinders. I replaced all 6 injectors.

 

Thanks for the reply Skully, I knew it sounded off but the only knowledge I have of these engines are from working my '83 Maxima that's still in the garage due to engine timing issues. Learning as I go, hah.

Ill head out to the car today and try what you said and let you know what it does.
Ill have to post a video of what the car sounds like while driving to give you a better understanding of what I mean, it's difficult to get an idea of something through text hah.

As for the injector and spark wires, could they be playing a big part in the performance drain I'm having?

 

Yes very much so. What mine did was revv decennt in neutral, it was missfiring a little, but put it in gear, and try to drive it, was just brutal...I had to take a run at the car trailer just to get it up, nerve wrecking. After changing out the injectors, I actually put an inline filter before the fuel pump as well. There is still crud coming out of the fuel tank, but the filter before the pump is working well!