ckurtz2

Just what I needed, thank you!

Makes sense, thanks. So I am starting to work on this now. On the old alternator connector where it has the S and L port. Is the S one the connection that switches? And then the L wire is what I connect to a constant 12V force? This may be a stupid question, but I want to make sure. On my car the L wire is striped white and black, while the S connection seems to be solid yellow.

@Mike I got them pinned to the top of my search bar. Definitely going to be handy when I start testing all the AFM and other electronical stuff.

Thanks guys, hahah. Made me laugh. I will take note to not do that when I rebuild the calipers🤣😎 Made a gasket from some old gasket like material I had. Here is my masterpiece of craftsmanship (I cleaned it up a little more after this photo) @Captain Obvious No I never did an initial vacuum check. I am waiting on a part to come in so I can rewire the harness for an AM alternator, so I am just using my time to try and fix the vacuum leaks. Not a bad idea at all though so I could have gotten a benchmark test, bummer. I will do one when it starts though as a benchmark before I start tinkering with other things.

Just pulled it off to double check. Behold... no gasket 🙃 I am amazed the car even ran haha. With all these leaks adding up it had to of had literally zero vacuum. Looking online I could not find a gasket for the AAR, only for the CSV. I did see there was a gasket for the CSV luckily. Does anyone know where to get the AAR gasket from? Only place I could find it was on MSA and it was unavailable.

Thanks! Got the TVV vacuum ports capped. Next thing I noticed is that I have no gasket between where the air regulator goes into the intake manifold/throttle body. Is there supposed to be one? The place I am talking about is in the photos below.

@Captain Obvious Thank you so much! I will just cap both of the vacuum ports then and leave it on. Hopefully by this upcoming weekend I will have everything corrected and together. If it still runs like trash I will go straight to a compression check and get back with numbers. And then the real fun will begin. Lets hope it doesn't come to that haha.

Time to reboot this thread again @Captain Obvious I got the freeze plug at the back of the block where it was leaking replaced, a new 5speed, clutch and all those fun things with it installed as well. Now back to the engine demons. All I have left is to try and fix all those vacuum issues I had, and fix up some new alternator wiring for an 80amp one I got before I try to fire it up again. The more and more I started looking closely at how my vacuum lines are set up the more disappointed at myself I have become. I had ran the vacuum from the front facing point on the throttle body straight to the distributor. I also had run a vacuum line from the one that faced back on the throttle body straight to the carbon canister. Not to mention the line was to big and pretty much floated on the ports. So ummm yah, disappointed in myself regarding that. Plugging the rear one, and then fixing the forward facing one to a T running to the canister and vac advance should fix that like you mentioned. Just waiting on 4mm vacuum line because my local auto stores did not have them. 🙂 I also noticed that the large vacuum hose for the air regulator did not have any clamps and was actually pretty loose which also I am sure added to my vacuum problem. Just fixed that today. And the icing on the cake was thermal vacuum valve. I have the coolant lines properly set up on it. However, I capped one of the vacuum ports and sent the other straight to where an AC vacuum line is supposed to be (and it was also loosely fitted). I also have no AC. So my question is, Should I completely remove the thermal vacuum valve, or should I just plug the vacuum ports for it? What exactly is its function? I deleted EGR and BPT.

Thx! @SteveJ @Zed Head I read through the whole post and it actually seems pretty straight forward! I know that post is for a zx alternator, does that still mean I need to do that for this alternator that isn't a zx? What would happen if I just removed the external regulator, put on a new T to plug in and bolted everything up? Without splicing those wires near the fuseable links. As you can tell electronics aren't my forte, but they do make me curious.

So you did not have to rewire anything like what was in Blue's tech tips, besides putting on that new t-connector and removing the external regulator? In addition, by chance does your friend have a part number for that connector. Zcardepot stopped selling them:(

Hey guys, My old alternator failed, so I decided to upgrade the alternator to an 80amp alternator from zcardepot: https://zcardepot.com/products/alternator-high-amp-80-240z-260z-280z . I did some research on how to rewire some of the components to accept the new alternator, and this is all I could come across. He used the same alternator I got for his 240z. Is there anything specific differences between the 240z and 280z that I need to watch out for regarding alternator wiring? I am not sure how I should setup the wiring, besides what I found from that forum post. I figured I would just copy what he did, but any advice would be wonderful so I don't fry something:) Here are some photos in case they help.

Best thread I found was this. What you recommend makes absolute sense to me. Thanks! Do I just measure the PP heights, or do I set the PPs on top of their corresponding flywheels and then measure? Reason I ask is because I am using a Fidanza flywheel and it may be different from the chunky original. @Captain Obvious Roger. I will get back to you in the future with the demons that I come across. I am sure I will need assistance doing away with them🙃

@siteunseen Seeing Rod Stewart, this song, and your comment was just perfect.🤣

@Captain Obvious I know 100% then that I have the throttle body vacuum messed up, not sure how I have it setup until I get home this weekend. I will let you know then. Plans are to get the new rear main seal, freeze plug, lightweight flywheel, clutch, and trans into the car this weekend. Switched to the 81zx 5speed for that nice overdrive. Still probably a month out till the motor is safe to run and begin diagnosing again. I need to figure out which driveshaft I need, whether the 81zx, or the one that came with the car (seem to be about 1/2 to 3/4 inch different in length) rebuild it and toss it into the car. As well as decide which clutch collar I need to use, whether from the 4speed that came with my car, or the one from the 5speed. Seems to be some debate with that, because it says to use the proper collar with the clutch it is meant for. But my clutch is an ACT aftermarket clutch for the coupe models with the smaller coupe flywheel. I got it from here... https://www.autohance.com/act-nx1-hdss-clutch-kit-heavy-duty-hd.html?gclid=EAIaIQobChMIhISB4qnW7wIVTx6tBh0pFQwAEAQYBCABEgJDpvD_BwE . Which is compatible from 1975 all the way through the 90s. I don't know if it actually matters what collar I use. If you have any advice that would be wonderful. You are right. Going to start with a compression check. Then I think I will test the water temp sensor and then AFM. If those check out I believe it is going to be my vacuum issue you recommended. Like you said, peel away the layers on that onion haha. Thank you everyone so far for helping me out, I have been on my own for a while now and it is really nice to get some advice. Found this, which will come useful when testing the AFM and such. 280z EFI Bible

@Zed Head Just the information I was looking for regarding the PCV. Great idea! BAT definitely may come in handy

@Captain Obvious Great catch! Could of just save me my car in the future:) Now the connection pointing towards the rear is the one for the BCDD correct? In my sixth photo. Actually looking at it I don't think it is. Anyways, I can't remember why I did it, I think I saw a diagram somewhere online. But I believe I have that running to the smallest line on the carbon canister. No idea if that is right. I had tons of photos on my phone when I disassembled the motor, but broke the phone before I got it back together, and didn't have the photos on the cloud. Was a catastrophe for me pulling up diagrams and what not. I remember connections like this confused me. Regarding the forward pointing vacuum port, which one are you talking about?

I agree, and I will do some more detective work in the upcoming weeks to give everyone some real numbers. Here is something I noticed. Does it matter the way the PCV system is set up? I noticed through a lot of photos people doing it different ways. For example, I have mine hooked up before the throttle vane, while some images show people capping it there and setting it up like this. Essentially, the reverse of how mine is capped. I would give everyone numbers now, but the trans is out. The freeze plug behind the block had rusted through and was leaking. Took the liberty to change to a 5speed while the trans was out.

I had a machine shop resurface the head, and do a valve job, and install springs. I installed the cam and rockers and such. I was super carful when installing. Made sure the engine and head were both at TDC before installing. Of course there is always room for error. I think the next step is to do a compression test for me to check that. I am at college, and go home during the weekends to work on the car, so I can get you official TDC verifications this weekend. Trans is out to fix a leaky freeze plug, so I will give the compression check at a later date. Thanks for the help so far!

I believe different 280zs had different PCV setups. Not sure if mine is right, but I do have it like it was when I got the unmolested car. Like everyone says though, who knows if what the original owner had was right. Regarding the EFI ground. If you mean the two connectors that ground on the intake, I believe it is grounded. You can see it on the first image below the air regulator.

Ok, I am totally up for suggestions, I tried to just "copy" what the engine looked like before I played with it. Here's a photo before I went and started toying and refinishing things.

ey guys! I have a 1977 280z which used to have the California specific emissions tech. I recently "refreshed" the engine after I got it. I completely redid the fuel tank and fuel system from the tank back going as far as to replace all the hoses for the vapor tank as well. I am just going to list off new things. rebuilt fuel injectos new fuel pressure regulator new fuel damper fuel lines fuel pump rebuilt fuel rail rebuilt head and new headgasket all new seals around the engine spark plugs rotor distributor cap plug wires oil pressure sender water temp sendor water pump/ radiator / fan clutch / thermostat etc cold air intake intake hoses at AFM vacuum lines new fuseable links new fuses inside the car under the passenger dash area several cleaned up grounds throughout the car I also modified the EGR system by removing it, along with the BPT system. I just did this to simplify things. I also have a 6 to 1 header from MSA going back to a 2.5 in exhaust. This deleted the catalytic converter it had. Other major change is I removed the AC. Might still be some things left over like the vacuum canister, but they aren't hooked up. Anyways, I am positive the mechanical timing on the engine is solid. I also set the ignition timing as the sticker on the hood. I think it recommended 10degrees BTDC, could have been after tho. The car starts beautifully like a top. However, cold or warm it cannot rev the car. If I hold the gas pedal down it will slowly rise, but then it sounds terrible and won't go further. My assumption could be it is misfiring. In addition as the car heats up it will begin to stumble, buck, and eventually die. Quite sad to watch. I would also like to mention it idles right around 850rpm. Even when cold. So I went to troubleshooting. If I unplug the water temp sensor the car will die pretty much immediately, so I know that it is at least getting connection. I tried adjusting the idle speed and it pretty much has zero affect until i close it, and then it will choke out and die. I also tried to test vacuum. People recommended removing the oil cap and see if the engine runs worse. I did, and it made zero affect to how the engine ran. Which made me think a vacuum leak, although I can't find one for the life of me. Except that maybe I did not plug the EGR right. Next came the AFM. I noticed that as the car warmed up I could watch the counter balance thing on the AFM begin to bobble (representing the vane itself inside bobbling). As the car got to operating temp the AFM bobbles more and more until I can see it making extreme movements to stay alive. Then the car dies. So I thought, lets help the little bugger out. So I had a friend slightly hold the AFM open so it would run a little richer. The engine immediately ran SOOO much smoother. I tested further and had him open it slightly more as I followed with my foot on the gas pedal. And the engine would rev up with it. I actually could get it to rev all the way to 6k rpm. Sometimes it took a while to get there, other times it would rev there super quick. Never would reach redline though, most likely because the mixture was still way off. So to me this rules out that spark as an issue. But I just have no idea what it could be. I really don't know where to start. I never got to see the car start before I redid it, because it was so crusty and likely had a blown head gasket. I actually drove the car about a quarter mile, by running the AFM about 3 cog teeth richer. Although I had what felt like 50hp. Can't say it was a great idea, but I needed a pick me up. I will provide some photos and let me know if you see anything immediately wrong with how I hooked things up. This is my first z car and I am on that initial steep learning curve. I also am based in Phoenix, Arizona. If you or anyone you know would want to help I'd be happy to host.

Exaclty, a big confusing onion, that makes your eyes water the further you peel away at it.😁 These are all great things, I'm definitely going to check into. I am going to make a dedicated post about this problem, and maybe you could help me out there!

Hey thanks! I have a vacuum line over it, but it seems kind of loose. May be something to check out.

I pulled apart the intake and everything on it and cleaned out the inside and out. So I am pretty pretty sure that shouldn't be the issue. The fuel pump works, because if I leave the ignition on and move the AFM vane I can hear it turn on and run, as well as it shoots out the injectors. Learned it was shooting out the injectors (rebuilt) because after playing with the AFM with the ignition on I went to start it up and had a backfire as loud a 12 gauge go out the back..... Shame on me lol. Won't make that mistake twice. When you say change the idle speed do you mean the idle screw on the intake? I have played with that while running, and it does pretty much nothing until it is totally closed and the engine will die. No difference when I loosened it all the way. Another sign it may be a vacuum leak?

The vane itself moves freely. There's some pressure, but that is from the cog that holds the spring tension inside. It doesn't bind up at all when moving it. The things I modified was that I removed all of the AC components, EGR delete, and BPT delete. As well as a cold air intake. I have the same PCV hose that the car came with on it. Looked a little crusty, but wasn't cracked, replaced the PCV valve under the intake as well for good measure. It's the weirdest thing. The car starts up fine. As the car heats up you can watch the AFM begin to bobble. The bobbling then gets worse as the AFM tries to correct whatever the hell goes on, and then finally the car will buck and die. However, I can keep the car running decently smooth if I hold the AFM vane open so it runs just a little richer when it sends the signal to the fuel injectors. If I let go it bucks and dies. I have looked up this problem extensively, but it seems no one else has written about this problem. There is so many problems it could begin I don't even know where to start, so I went to the logical conclusion of bad vacuum not opening up the AFM properly. I am all ears!