TheCrazySwede

You are correct, sir. Checked and everything is seating properly. I checked my vacuum via the port that connects to the brake booster and my gauge is hopping all over the place, suggesting a vacuum leak somewhere. Manifold is tight and all the gaskets on the Carbs seem to seat properly. Since this is a new engine (~1,000miles), could it be needing a valve adjustment after break-in? Perhaps that's what's giving me those wonky readings.

I don't think my OER's are setup like that; what Carbs is that diagram from? Everything seems to seat properly. The only thing I have yet to replace are these tiny aluminium gaskets sitting on the pump jets. I'll replace those and see if it still leaks.

Floats are within spec. Even tried lowering them - no cigar

Tried smaller pump nozzles - no change. I do notice that even with pump and motor off, there's still dripping from the nozzle into the barrels for a few minutes afterwards.

Lowered it to 3psi - still drips. Could the size of the pump nozzle make a difference? I have one size smaller. I'll give that a shot and see if it does anything. My floats are all set at 29mm

Ok, so I tested my needles and all of them seat properly. Ran pump with one unseated top at a time and all the seated ones remained shut and never leaked. My fuel pressure is still within spec and hasn't been an issue before...but what can I lower it to? 3psi?

Yup, larger filter by pump and small right before regulator in engine bay. Hmm, wondering if maybe it was a batch of bad gas in there from my last fill up or maybe nasty junk in the gas tank that managed to get past the filters...if that's a thing. Thought the filters would keep stuff out, haha. Just odd that it all happen so suddenly and simultaneously throughout the Carbs - which is why I suspected fuel pressure first, especially since the car's health changed over it just sitting for a couple of hours after running healthy for several months. I'm no carb expert, but I suppose I might have to take these suckers apart - was hoping to avoid that. But I can't keep running the car like that until I fix it. Don't want fuel to make its way to the crankcase with how rich its running...

Just seems so sudden. Been running flawlessly for months, did a coffee run and on the way back problem occurred. Car was driven regularly throughout the week and hasn't sat for long. Odd that multiple needles have issues simultaneously out of the blue. Thinking maybe something in fuel line that spread across carbs and maybe clogged up something? Is that a thing?

Hello fellow Z'ers, Recently started having an issue on my Z running really rich and I can see fuel dripping from the nozzle into the barrels. Car ran excellent for months; then suddenly went to start it and noticed my AFR in the 9's and noticed the drip. The motor is not stock; has a .495 lift and 290 duration, so keep that in mind. Idle Jets it ran - 65, but I also tried swapping in 62.5 and 60's and the AFR stayed the same. Mixture screws are 1.5 turns out. Fuel Pressure is right below 4psi (with 3.5 - 5psi spec) and was tested with two different gauges Floats at 30mm (within 29-31mm spec) Pump nozzle sizes tried: 40 and 50 It drips down from multiple barrels, not just one. Can't seem to figure out why this is happening since nothing was changed since it last drove fine. Any ideas where to start next? Thanks!

Ok, it's been a while since I gave an update, so here it goes! Every wire in the car, from front to back, has been redone, replaced or discarded. The car runs on what is needed. No heater, no fan controls, no radio, no antenna switch - not even the fuel light was spared. The car runs on only what's needed, nothing more and nothing less. The issue with the idle and pilot jets is resolved, too. Idles and runs on all six cylinders now! I'm not sure what did it, but I replaced my filter, cleaned my tank, cleaned out the carbs as best as I could and messed around with the idle mixture - and eventually it worked! I've spent many hours now diving into every piece of literature I can find on DCOE carburetors and I've surely learned a lot to the point where I feel very comfortable working on these guys. What I couldn't find much on was what parts of the DCOE family (Weber, Mikuni, OER, Solex, etc.) is interchangeable - specifically talking about jets. What I learned is that Weber idle jets work as long as you get the appropriate seats for them. Mikuni Air Correctors work on these carburetors, too, and fit right into the emulsion tube. The mains, however, only seem to fit with OER ones. I went through a lot of different setups to find something that works for this engine and so far the perfect recipe seems to be: Mains: 135 Air: 160 Idle: 65(OER)/65F9(Weber) I am currently running 62.5 pilots, but it's a tad bit too lean when cruising. i've tried 70F8's and 70F9's and they're both too rich. My guess is that 65's should fit in perfectly, but they're still on their way from Japan since I'm going with the OER one. The F9 designation on Webers is the same as the OER. I also got a wideband hooked up now so I can get proper readings on this thing. At idle I'm currently sitting at 12.7-13 AFR, it goes up to 14 when cruising under 2kRPM (should richen up a bit with the 65's) and I get in the mid 12's at WOT, which seems to be the sweetspot for this engine.

So the Z no longer has electrical issues! I ended up ditching my current harness and re-modified a harness out of a 73 240z and used that. Works great and no longer giving me issues! Also installed some led bulbs in the car and some HID's while I was at it. I' currently facing an odd issue... During idle, Cyl4 and 5 don't fire. I checked for spark and compression - both give positive results. Turning the idle mixture screws don't do anything, either. Something get stuck, possibly? Under load I believe the engine runs on all six, but definitely not under idle (disconnected Cyl4 and 5 serves no changes to the idle.) Anyone have any tips as to why? The only thing I can think of is maybe the needles getting something stuff in there... I tried spraying starter fluid into those carbs and didn't get any change in idle behavior - but I do get that from any other carbs.

Awesome! Did you paint those yourself? I have 45's

Quick update: Bought a new harness and I'm going to strip the car down and re-do all the wiring. Figure I'm going to want to do that anyway. Hoping I find something along the way. Here's the sound of the car with the carbs better tuned (Getting a hang of it!)

So been doing some more tinkering. To try and attempt diagnosing my electrical issues, I've reverted most of the electrics to stock: New Externally regulated alternator New voltage regulator New battery cables (x2) New OEM Fusible links With key set to "ON" - Alternator reads 12.20v Fusible Links read 12.20v Battery reads 12.23v As soon as I turn on my headlights, the volt gauge in the car drops to 0. Running lights, parking lights and dome light won't come on. Same effect occurs if I try to turn on the fan, use wipers or hazard lights. Headlights come on and turn signals work. One of the brake lights also causes the "short" issue, but with that particular light disconnected the issue no longer occurs. Swapping bulbs with one that does work still causes same issue in that particular light. Still, Alternator reads 12.20v Fusible Links read 12.20v Battery reads 12.23v I checked the ground wire from negative battery - good. I checked my fusebox - good. When I first made the swap, the alternator was pushing out 17v before I swapped it. It may have fried something along the way, but I don't know what. At this point, is there anywhere in particular I should be looking?

Moves just fine. Haven't had any issues with it. I got the carbs air synced (5kg/h), the floats set, the linkage synced and all the right jets (in theory) - now I need to adjust the idle mixture and accelerator pumps, if needed. Zedyone recommended an AFR kit that I recently got to help with mixture tuning, but I'm having some trouble with electronics at the moment. My voltage drops (dives) and shorts all accessories the moment I use any accessories, including head lights. Fan, headlights, windshield wipers, etc. All of these short out all the electrics. The only thing that doesn't are the turn signals and my electronic fuel pump that's hooked up to the starter. One of my brake lights also caused the short (volt drop every time I braked) but I disconnected it and now that doesn't happen, but the previous issue remains. Since I air synced the carbs, they've began to stutter and hesitate upon acceleration, so I definitely need to figure that out, but I would like to solve the electrical side of things, too. Got a lot on my hands right now!

Are you talking about the throttle return spring I have? That was only temporary - it's not there anymore

Thanks! I'm replacing the big 5mph bumpers with the slimmer ones. Had the whole thing off when I was dropping the g-tank for cleaning

Exhaust by Abarth

Thanks a lot guys! You are all a great! Really appreciate the help I'll feed some more background into the situation. I recently went from an EFI L28 to a carbed L28 Only thing new, electronically, is an electronic fuel pump. Since engine swap, I noticed my volt gauge would read past 16v. I thought maybe my regulator was bad or maybe alt. I replaced alternator with new internal regulated version. I jumped the cable that connected to the external regulator, as instructed on Atlantic Z. (Boy, that website is amazing!) Since, I've noticed my alternator has still had issues where it outputs a lot of juice and burns my fusible link. The link that keeps burning is the one that goes from the alt and to the battery. Looking at the wiring diagram, it also connects into the voltage regulator (the old external one that now has its connections jumped.) Another thing to note is that this issue I'm experiencing now is not new. I was having similar issues with the old alternator, too. And with the new one - but the issues sort of went away on their own. I'm thinking maybe there's a ground wire somewhere that isn't hooked up properly. When I did the motor swap. Or maybe my fuel pump hookup is jacked - who knows. I'm going to do some back-tracking to try and find the sucker causing this issue, since I had no electronic issues prior to swapping my motor. Funny how I went from an electronically motored engine to a fully mechanical one and ended up with electronic issues, haha

Will do! I was having an issue with my alternator pumping out too much juice and burning up my fusible link. I replaced the link....and now I'm having this issue. Could be either link isn't doing its job or maybe wiring inside harness got burnt?

Thanks a lot for the help, gentlemen! I've checked the fusible links and they are all ok. None of my fuses inside the fuse box look popped, but I'll replace them with new ones just in case. Only things that work are headlights, electric fuel pump and cranking to start motor. I noticed that when everything shorts out, that annoying "beep" sound that indicates key in the ignition with the door open goes away, but if I disconnect my battery and reconnect it, I hear the annoying beep 4 times before it goes away again. This is is all whole all other electronics are out and volt gauge reads 0. If I turn everything off and wait a few minutes, power comes back.

1977 280Z with upgraded alternator and voltage regulator jumped. My gauge in the car will read 14.5v and car starts just fine. If I turn on my running lights, all electronics die out in the car and gauge drops to 0. Turn everything off and wait a while - power comes back on. If I use my turn signals, nothing happens, but if I use my hazards - same thing. All electrics die and voltage reads 0. Same goes for fan. My headlights work, but nothing else does. Even during the "all electrics dead" period, I am able to crank the engine and start the car. Using a voltmeter, my battery gets 13.5v with engine running. With all electronics dead, it reads 12.5v at both battery and alternator, even though gauge in car reads 0. Any ideas why? Thanks!

Out with the Webers - in with OER Carbs My 'JDM' inspired exhaust

So I think my borrowed Carbs might have taken a dump on me. Either that or it's the fuel pump, but I haven't had the time to check the pressure yet. I do know that the carbs have been running like crap due to the bad accelerator pumps. Engine cranks, but won't come on. I took the top lids off each carb and noticed they were covered in "cheese," as I like to call it. Not the sharpest blades in the Weber arsenal these lads, I'm sure. At first I thought the carbs might have been flooded, so I cranked the engine for about 10sec with WOT to empty them out and then tried starting it again, but to no prevail. Tried some carb cleaner, but that didn't do much. At one point, I did get a little How much fuel is there suppose to be in the bowls? The floats are all properly set. It had been raining pretty hard, so maybe the wet/moisture wasn't complimenting my dizzy or the carbs. I'll check it again once the weather dries up.