rcb280z

pure luck! and awesome score!

Zed Head. That is correct! I remember this all to well when I replaced my carpets about 12 yrs ago. I will be checking that next and update this post on my find. I'm going to look through my FSM again to find this info as well. Thanks.

Steve, I am the second owner since 1985 and don't think the PO hacked into anything.

Anyone that has read my "I think I'm getting somewhere post" and other EFI post's know that I am chasing a fuel pump shut off issue. My question is; is it normal for the fuel pump to run with the EFI relay unplugged? That's both the white and black connectors unplugged. The fuel pump still runs in the "on" position, engine not running. As you can tell I'm drawing at straws right now because I'm running out of things to test using my FSM. I'm always able to find and fix any problem with my cars but this one is baffling. Appreciate any help at this point. Bob

All I need is the 7 pin and 3 pin connector. Will you sell only those two to me? I have already replaced the rest of them. Nice score though!

Zed Head, yes that is the correct one. It is the one to the drivers left leg and up. Two connectors, the top one is white the bottom one black. Does it seen strange that I can unplug those two connectors and the fuel pump still runs?

Ok Dave, I did forget about something. I have that CRS disease lately it seems. The only rewire I can think of now was the parking light and headlight harness upgrade I did. I purchased the harnesses from Dave, Zs-ondabrain. I am very pleased with the product. I didn't have to splice it in anywhere. It was a direct plug into existing connectors deal. I know it can't be from that. I honestly don't know how long it has been this way. The only reason I started looking into it is because I saw in post's here and other sites that the fuel pump is not supposed to run in the "on" position if the engine is not running. That threw up a red flag because mine does run in the "on" position when the engine is off. Hope you will continue to help me diagnose this. I would appreciate it.

my oil pressure sender is on the block with one wire connected to it. but aren't they all this way except for 78 and on?

Dave, I had an electrical fire in the "engine bay" harness 8 yrs ago. Found an exact match harness that was in excellent shape and it was easy. Didn't have to splice anything in anywhere. I have owned the car since 1985 so no rewiring that I know of. It probably would have shown itself already, I think. So you are saying while the pump is running to start pulling fuses/fusible links/connectors one at a time and replacing what I pull if it doesn't have any effect correct? Thanks.

UPDATE I honestly don't have a clue now! The only thing I haven't tested is the ignition switch itself. I thought it was the EFI relay but when I unplug it the fuel pump still runs. Now I'm getting discouraged. There was another post that had the oposite problem from mine and I'm not sure the outcome. I will keep searching.

If it is a problem you have been experiencing lately like your post reads then I would assume the thermostat is stuck open. remove the thermostat outlet and check it out. Let us know what you find. Bob

UPDATE: I tried to remove the EFI relay from under the dash on the drivers side but couldn't get to the top screw! I have stubby screwdrivers I just can't get to it. It doesn't help to have extra large hands in this case. Anyway, with the EFI relay unplugged I decided to turn the key to the "on" position and the fuel pump came on! How is that possible if the relay is un-plugged? Back to the drawing board. This is why you want to test things before you just start throwing parts at it. I'm going to start going through the FSM again. This time I'm going to look at ignition circuit. Maybe I'm missing something there. Ideas anyone? Fastwomen? Thanks. Bob

I agree with Steve. I pulled my 280 out when it had only 91k miles because I was bored. Realized when it was apart I didn't need to do anything. But ended up having a valve job done and did a "minor" overhaul to the block because I had it out. Waste of time. Didn't change a thing. That was 25 yrs ago too. And still runs the same. That says alot about the straight six engine. As long as compression is the same across all cylinders I wouldn't worry about it. just my 2 cents. We all have our own opinions. It's what you feel is best. If you decided to let us follow the rebuild with you.

where in Cali are you located?

I just pull all plugs and use my remote start to bump it over and that makes a quick job of it. Been doing it this way for years.

Fastwomen, As a matter of fact I just finished those exact tests. I'm getting that same 7.19 ohm reading on the AFM plug. I get nothing on the AFM until i plug the connector back in. I tested the AFM while I had it out of the car and it tested right so I'm guessing EFI relay. I will have to test that next I guess. I know enough to keep my Z in good running condition since 1985 but when it comes to electrical (even with FSM in front of me) I'm lost. I have pretty much read all your post's and plan on trying that yogurt cup test some day for something to do. It sounds interesting. Hope you can continue to follow my progress on this issue and continue to offer your knowledge. It may take me a few days to get to anything else right now unless I happen to get a few extra minutes tomorrow. Thanks.

Ok, so in my "How weird is this" post Im trying to understand why my fuel pump is energized with the key in the "on" and "start" position. It's a 5/77 280. The fuel pump shut off is different in the 8/77-78 models. I don't have much time to spend on the Z these days so what little free time I have is dedicated to finding this problem. When I test connectors 39 and 36 (AFM still hooked to 7 pin connector) for the fuel cut off I get 7.19ohms with contacts open and closed. I should mention that I am connecting my ohm meter to the 39 and 36 connectors inside the AFM. Just behind the black cover. I should get no reading when the contacts are broken. I even physically made and broke the contacts between these 2 connectors and still the same reading. So I'm thinking It's in the EFI relay. Maybe a set of contacts have fused together. Any thoughts? That could be what is slowly draining my battery. I drive it maybe once a month or every 2 months. I've been accused of speaking in broken sentences, hopefully that doesn't happen when I type. Thanks for any help.

Anyone in Ventura, Oxnard, Camarillo, Santa Barbara area's and like working on their Z car's as much as I do? There are times when I could use a "third" hand and don't know anyone that wants to or needs to work on their car as much as I do. Great way to meet people and make new friends. If you are interested pm me. Bob

Black gold man, I did just look at ef-16 of the 78 FSM and they show all the relays in the engine compartment which mine are not. Any other ideas? Thanks

It's definitely a 77. Maybe I have an incorrect EFI relay. I did a search and see that from 75-8/77 uses the same efi relay. After 8/77 it is different. I will however look at the 78 FSM just to confirm things. Thanks

So I opened up my afm on my 5/77 280z because my fuel pump (I thought) is running when I put the key to the "on" position thinking I was going to have to adjust the arm that breaks the contact point for the fuel pump. I know the pump is usually only powered in the "start" position. To my amazement the contacts were not making contact! So I made them make contact and I heard something else come on. I can't tell if it's the fuel pump, something else is running at the same time. I looked around in the car to see if any other accessory's were running but couldn't see anything. Now for the weird thing, my fuel pressure gauge builds pressure with the key in the "on" position! I'm sitting here reading this myself and saying "not possible". But it is. Because it is happening! Please advise. Thank you.

Assuming your car is a ca car and not a federal car there are a few things that come to mind. Make sure you can pass a visual inspection. Meaning, make sure all smog equip is still in place and operating correctly. If you had the cat changed make sure there is a date code and manufacturer code (mandatory now). Before I had my Z smogged 2 years ago I purchased a cat from MSA and these codes were not there. The station will look under your car to verify this. If they are not there they will fail you. Got my money back and bought a "california" correct one from a local muffler shop. Also make sure the seal on your gas cap is good. If it doesn't hold a vacuum they will fail you. That's all that comes to mind right now. I'm sure someone has something else to add that I forgot. Good luck and let us know how you did.

Oh yes, know Michael all to well at Sun West Motorsports. Visit with him a couple times a month. Don't take my car to him because I like the trouble shooting aspect of it myself and the satisfaction of fixing the problem. The cold start valve is good according to the FSM test's. It's at 3 k-ohms when cold. So I think that is good unless I'm not understanding something.

Thanks grantf. I will take a look at that next. I bet that is whats going on because I had to have a Z mechanic adjust it to pass smog.

I have a 77 280Z and am trouble shooting the cold start system. I have been reading post's regarding cold start issues and think I have stumbled on something here. Correct me if I'm wrong but isn't the fuel pump supposed to only come on in the "start" position? If I turn my key to the "on" position my fuel pump runs as well as the start position. And if this is the case then I need to spend time looking at my AFM correct? I know what tests to run from looking at my FSM I just need some reassurance that I'm heading in the right direction. Thanks for your help. Bob