aochider

great, thank you very much for the advice! btw, just so im not chasing something totally unreasonable, but i should be able to get my L28 down to 800rpms without it dying or surging periodically, right?? EDIT: that is my near-term goal so it would be helpful to know if i can actually achieve it. i will, of course, still look at those resources and try to learn as much as possible.

i understand how to do each individual component of what you said (timing advance/retard, jetting, vacuum advance, lean/rich mixture) but i had on clue that timing affected jetting. do you by chance know of a good resource where i can read more about it? im having trouble finding important details like that and am instead finding mostly the same old "plugs are fouled, must be rich" kind of advice. thanks!

1978 280Z, Holley 4160 (pn 8007, 390cfm), Arizona Z intake manifold I'm having trouble getting the car to run at 800RPM. I have the timing set at 10deg (I tried 15, but maybe did something wrong, because the idle could not get very low at all when the timing was that high). The idle mixture screws are at about 1 turn out, and the idle screw is about half a turn in (any less and it ceases to move the throttle at all). Since the idle screw is basically all the way out, I've been adjusting the mixture screws with vacuum hooked up. The lowest I can get it without the engine almost dying and then surging is about 900-950RPM. That produces about 16-17 in/Hg of manifold vacuum. Possibly also of note: unless you give it gas fast enough for the pumper to put in a lot, the engine almost dies when the throttle is pressed. Not sure if this is a symptom of the idle mixture screws or if I just need to put on a more aggressive pump cam (I'm using orange, ie, 41R466). I read Holley's guide to tuning idle, but the car just dies or almost dies and then surges (to about 1200) if I tune down the idle mixture screws. Any advice please? Thank you for any help to a new-to-cars, really-new-to-carburetors person like me!

thanks for finding those links. im going to keep cleaning them and reading this diagram to better understand how it works. it pretty much looks like all four of mine are in pretty rough condition so i might as well clean them all for now.

whoa, okay, that is good to know! thanks for telling me. ill go to the local auto store and i imagine they should have some fusible link wire. EDIT: i should also mention im working on cleaning this one up to see if that will be enough, but im do like to go out sooner-rather-than-later to buy little, cheap things that i may need.

i just checked them, and the black one (my labels are worn off) was barely, mostly-not functional. i put in another piece of wire just temporarily to check, and sure enough it works! im guessing i can just get the same gauge of wire to replace it? thanks a lot for your help everyone.

thanks for the info! im not sure about Acc., but On and Start do nothing. i tested things i would expect to work when in the On position, specifically my wipers and turn lights. the dash brake light also doesnt work. and the engine does not crank at all when in the Start position. there are no relay sounds either in any key position. EDIT: im going to go out and see if voltage will run through the 4 wires that connect the ignition switch. i did that yesterday and it looked like small voltages were running between them, but maybe i made a mistake and one of them is dead.

okay, thanks. ill check the fusible links (because ive already replaced the ignition switch). would the ignition module have anything to do with things like the wipers and turn signals?

This is more of a general car question, but it happened on my 1978 280Z with a Holley carb. I started the car just fine and had it idling so I could set the timing. It took me 5-10 minutes (or so, fast idle was still active on the electric choke) to get my timing gun and when I get back to the car, it dies right away. It was running just fine and then stopped as if someone turned the ignition to Off. After that, the car wouldn't start and any ignition-switched items do not work either (such as the wipers, turn signals). The constant power stuff like headlights work fine. The battery is at 12.62V and I had it load tested at a specialty battery shop just 2 months ago, which was when a similar thing had happened to me (except I was on the highway that time!). The time two months ago, however, seemed to fix itself. So, I don't suspect the battery, but I still tried jumping it to no avail. I also put in a new ignition switch, and same result. I checked all of the fuses on the passenger side and they all looked good. I'm stuck. The only thing I can think of with this time and the last time two months ago is that it was exceptionally hot. I have run the car fine since then, but they were at times that were at least 10F cooler. It seems to me that wiring is the only thing left, but I'm new to working on cars so I'm afraid that there might be some other component that can cause such behavior. Thanks!

great info; thanks!

wow, i wouldnt have guessed that. ill try it asap. thank you!

I have a few questions for my 1978 280Z with a Holley 4160 (390cfm, pn 8007, arizona z intake). I'm new to carburetors in general, so I would really appreciate any help or at least pointing me in the right direction. 1. Does timing stay the same? (10 degrees at idle) 2. Does idle say the same? (800RPM) 3. Is there a need to rejet? I believe mine has already been rejetted about 2 sizes down from stock, but I can't verify because I want to avoid opening it at this point. Right now the car actually runs all right. It starts fine with the electronic choke and the fast idle keeps it at 1500 or so. However, it idles around 1000 (and if I try to lower it, it starts to run rough between 800-1200). It is also harder to start when warm than when cold. There is a slight lag sometimes when pressing the pedal, but I can't tell if it is because the pumper is putting too much or too little in. I also can't reproduce it each time, so I'm not sure if that is the problem. Thank you!

Thanks for the help, but I ended up going with the 12V at the regulator. I checked the wiper pins and didn't find any ignition switched ones. The BW at the regulator was simple enough though and didn't require me to go through the firewall or use anything other than wire, a disconnect, and a splice.

Yeah, it is a Holley carb setup. Hrm... Those are good ideas. The wiper would be the best, but from the battery with a relay on the coil would be good too. I don't want to run anything else through the firewall. Thanks for the ideas!

Is there a good 12V to use for the electric choke that is already in the engine bay? Apparently I'm not supposed to use the 12V to the coil, so I'm out of ideas already. I'd appreciate any help!