Pooky

Zed Head, the 77 source power comes from the voltage and fuel gauge. Specifically the alt warning light per the 77 wiring schematic. I also know this because I have been having a problem with my upgraded alternator, a 60 amp zx. I believe my problem lies in the fact that I installed LEDs in my dash and the current draw of the LED isn't enough to trigger the regulator in the alternator. Question for you is: Where did you hook up a link to the fuel pump? Under the hood somewhere or did you run a line from the back of the car? I really don't want to pull my dash again!

Hello Fellas, I just got around to working on my car again. Rechecked a lot of grounds and connectors with no success. No vacuum leaks that I could find with a smoke test or starting fluid. Switched out the AFM with an older one and the control unit but the car ran the same. I did find something, though. My voltage seems to keep going down. It didn't draw my attention at first because I've been running all these test with the key on. So this is what I found. My alternator doesn't seem to be putting out a charge. When running, no leads off the alternator read anything but house power. Nothing higher than the battery itself. I took the alternator to advance auto and it checked out OK. I DID do the ZX upgrade to a 60 amp unit years ago, however, this alternator has less than 100 miles on it. The new wiring is correct. I jumped the correct colors and got rid of the external regulator. Why is it not putting out more power? Am I missing something? I think this voltage issue could have been the missing link all along. Thanks in advance, Craig

Ok guys, I printed out the EFI bible and checked all the pins. I did have trouble getting a reading from the air temp sensor(pins 6 and 27) and the water temp sensor(13 and Ground). I finally borrowed a good fluke ohm meter and got some good numbers. The air temp sensor registered 2.624 at garage temp of around 65 degrees. I'm assuming where the ( . ) is doesn't matter. The water temp sensor registered 2.471 at the sensor but only 83.0 to 87.0 at pin 13 and ground. The values at the sensor aren't carrying to the 35 pin connector. Ill follow the wire next time I work on the car to look for an issue. I do have a question. I took off the air cleaner and boot to check the flap in the air flow meter. It moved freely. However, later when I started the car it ran like crap without the air cleaner back on. I was putting my hand over the AFM and monitored how the engine reacted. It may be common sense to you guys but obviously the air cleaner "resistance" plays a part in performance. The PO of my car put a K&N filter on it. Is it possible that it is allowing too much air to enter the engine which in turn throws the mix out of whack, making it run lean? BTW, all the other pin ohm testing check out ok. Craig

Hey Captain, I just went through the EFI Bible you sent me the link for. OMG! How did I not stumble across it at some point. I'm going to print it out and keep a copy with my other manuals. Unfortunately, I may not have time for a couple days to look into these suggestions but I'll let you guys know when I do. Craig

You guys have me questioning my connectors being on the wrong sensors! Here's a picture.

Hey Captain, I did not do anything with the throttle when I checked compression. I ran it for about ten minutes then pulled the plugs and coil wire. I turned over the engine four or five times starting taking readings at cylinder 6 forward. If the throttle being open is important I can redo it. I hope it is! Also, after going out and looking at my engine I realized that I DID NOT change my thermotime. I changed the temp sensor and the thermal transmitter. Funny thing is I remember boiling the water and deciding the sensor was good yet I changed it anyway. I'll check this out further tomorrow. Ill check out the EFI bible as well as I have never seen it before. Craig

Hey Cliff, the throttle stop is currently open to atmosphere. I think the picture was taken while I was trouble shooting. Good eye, though! Putting in another fuel filter is not a bad idea. I read somewhere on the forum there's also a screen type filter in the pump that should be checked. I've wondered about the internal condition of the tank. I'll revisit the coolant sensor as well. I replaced that and the thermotime in the Fall but I've questioned the wiring and connections. Thanks for the links. I'll check them out. Happy Easter, Craig

Yes Captain, the car is drivable. I drove it to church this beautiful Easter morning. It drives like a cylinder isn't firing. When driving at a steady rpm, no matter what gear, the car is jumpy. Its a rough ride when driving along a straightaway. I pulled each plug wire one at a time to see if it made a difference but it doesn't seem to. The plugs never seem to be too dry, too oily, etc. I rechecked my compression and the results ranged from 112 to 120 psi on a cheapy Amazon gauge. I put a new muffler clamp on and the smell in the cabin went away. However, the fumes do have a peculiar smell. I'd say its running rich. A new theory I have might be to move the gears in the AFM a tooth or two. If it doesn't do anything I can simply move it back. No mailnome, I grew up right here in the southwest suburbs of Pittsburgh. A kid I used to work with years ago started calling me Pooky one day for no apparent reason. One day when I was trying to think of a login name it came back to mind. Now my screen name is Pooky, Craig

Wow, I'm really impressed by you enthusiasts that go the extra mile(and then some) to bring life back to these rust buckets. I thought I did a bottom up restoration on my Z but you guys take it to a whole new level. Hats Off to You! Pooky

Thanks S30 Driver, I checked the things you mentioned. I took it for a ride today. So fun to drive! Can't wait to drive it once its running correctly. The Z ran half decent for the first 15 minutes. After a stop at my brothers house it ran like poo poo! Studdering and lunging.The grounds seemed tight enough. The fuel pump delivered an average 30psi while running. It would spike up to 33/34 when spiking and down to 28ish when idling at roughly 800rpm. I think my next step is to check vacuum. I've checked numerous times for leaks and found none or fixed what I found. I also believe I have an exhaust leak because the fumes keep coming into the cabin. Maybe that is part of my issue. I'll find it the next time I have it up. Another thing I noticed is that the car will stall out when I put on the high beams/electrical draw. The alternator puts out 14ish volts. Less at 800 rpm idle. Just throwing these things out in case it sends up a flag to one of the members. Thanks All, Pooky

More Images

Hello All, I "mostly" finished my '77 280z last Summer but I never did get it running right. I've searched this site over many topics and still haven't found the culprit. The car starts easily and idles nicely. It accelerates ok but holding a steady RPM causes the car to miss. At least that's what it feels like. The engine seems jumpy, like its running out of gas. It seems to get worse the longer I drive. Giving it gas seems to make it go away until I let off the accelerator again. Car History: I bought the car almost ten years ago. Drove it home and don't recall having any running issues. For the ten years I was real gung ho at first but then the car took a back burner. Thanks to Covid and time off this year I was able to get it to where it is today. Things I changed and checked include: Put a new ZX alternator in to go around the external regulator, fuel pressure seems to stay steady at roughly 35 psi and holds steady for a day or so when not running, I cleaned the injectors myself with an improvised spray can of cleaner and a 12volt battery. I believe they're all ok. Replaced all fuses. Replaced the coil with a flamethrower. This was a concern. I've since learned on YouTube that there are upper and lower limits that are important. My usual mechanic didn't think this would cause my problem. I've tried to check all my grounds and connectors. I replaced the temp sensor and the thermotime. Fuel filter. Battery. Cleaned my mass air flow chamber which I thought could be an issue. I have concerns that the distributor could be an issue. I question the wiring from the ceramic block by the coil. (I forget what its called) I did adjust my timing with a light. I used the light to also verify that all cylinders were firing and they were. My cylinders ranged from 48psi to about 57psi. A little low but I think in range according to my books. I have another computer that I haven't switched out yet. I'm sure there are other things I've changed and checked that aren't coming to mind but I'm frustrated to say the least. A lot of you guys check this and that for resistance and so forth. I don't want to get into that depth unless its easily explained. I'm at the point where I just want to drive it! If you have any suggestions about what I may have missed, I'm all ears. Otherwise, please let me know if any of you know anyone in the Pittsburgh area who knows these cars. Thank You Guys, Pooky

I'm very impressed with the amount of dedication to do it right. I like a good challenge and the reward of success but I don't have the time, will, or talent to undertake that project. Good Luck!

I made my own frame rails out of 14ga steel. Made a poster board paper pattern first.

As far as solid goes, it was ok. I welded on my fair share of patches. Totally solid now. Keep in mind I'm no welder! Some pics...