My 1978 280 Z car

[argniest]

Here are some good cleaning instructions you will want to reference before proceeding:http://www.atlanticz.ca/zclub/techtips/electricalconnections/index.html

I had a lot of green oxi-crust in the connectors near the front of the engine including @ the #1 and #2 fuel injectors. The C-clips on the fuel injectors are a lot easier to work with than the G-clips found elsewhere.

I read those instructions!!!!!! WOW very helpful. But I am unsure of which Z connectors are plated or not? is there someway I can tell. Man, I dont want to be filing/sanding things down only to find out it was a plated connection and that I had royally screwed it up by sanding away the tin or whatever!

[Jennys280Z]

I read those instructions!!!!!! WOW very helpful. But I am unsure of which Z connectors are plated or not? is there someway I can tell. Man, I dont want to be filing/sanding things down only to find out it was a plated connection and that I had royally screwed it up by sanding away the tin or whatever!

Good point, but a good rule of thumb is don't sand down anything that isn't oxidized. I've found you don't have to scratch the metal connectors to sand the oxidation off. If your connector looks clean enough you might not have to break the sandpaper out at all half the time. An inspection and at least a good lathering in Deoxit is worth it. My thesis for my own car at this moment is that cleaning all of the EFI connectors (sans the fuel injectors themselves) shown on that AtlanticZ page introduced a lean running condition for my car. Which led me to my AFM which led me to notice it was tampered with to run leaner.

The main reason to clean your electrical connectors is you will be working on your engine's performance from a "clean slate" that could result in making diagnoses easier. Getting back to "stock" is a good first direction to take imho.

I was reading on your other thread I didn't realize it was so frowned upon to just idle your car in the winter. I'll have to take mine out for longer jogs from now on.

Edited January 14, 2011 by Jennys280Z

[argniest]

Good point, but a good rule of thumb is don't sand down anything that isn't oxidized. I've found you don't have to scratch the metal connectors to sand the oxidation off.

What do you mean, if its oxodized? I am not sure what I am looking for when looking at each connector, to be able to be sure 100% if its oxodized. I certainly dont want to screw up a connector for no reason, and then have to worry about replacing it. I am not a solder guru, and would have to learn about that too. I have heard there are lots of wrong techniques for that kind of work.

My thesis for my own car at this moment is that cleaning all of the EFI connectors (sans the fuel injectors themselves) shown on that AtlanticZ page introduced a lean running condition for my car. Which led me to my AFM which led me to notice it was tampered with to run leaner.

So are you saying it was a bad idea to clean the EFI connectors at each fuel injector?

I already know my AFM has been *adjusted*. But there are sooooooooo many reasons right now that the car might not be running perfectly. I know some of them, and other reasons can be because of poor grounds and poor connections. And cleaning connections and grounds is definately something I can work through this winter.

The main reason to clean your electrical connectors is you will be working on your engine's performance from a "clean slate" that could result in making diagnoses easier. Getting back to "stock" is a good first direction to take imho.

Yes, I think its a good idea for me to clean all the recommended connectors in the engine area. And possibly other ones too. I read on this forum that a big whopping percentage of problems can be caused because of bad connections. Im talking about making a car run lean,run rich, and whacky electrical problems all over the place. So this has become a high priority for me to work on now before I do anything else.

And also, I am going to replace all my fuses in the fuse box with new fuses. Because some of them could be 33 years old. And they can do funky things too so I have read on this forum.

Edited January 14, 2011 by argniest

[ZCurves]

argniest - Sorry I have been off of this blog for a while...but you have been in the very capable hands of Fastwoman and Jennys280Z. I think you should pat yourself on the back for not getting angry at the situation and being all frustrated.

I'll see if I can help out here a little more. Please forgive me if you have already covered something....So from looking at the conversations on this blog, I believe that you should prepare a checklist so you are not chasing your tail and going nuts (been there already) and spending $$$.

So what do you have? (everyone, fill in any blanks..)

• Fuel Pump
  
• Fuel Pump Relay
  
• Fuel Pump Circuitry
  
• Fuel Pressure Regulator
  
• Fuel Filters
  
• EFI Circuitry
  
• ECU (Brain)
  
• AFM
  
• Oil Pressure Sender
  
• Tight EFI 12v connection to the Battery (White Cable)
  
• Fusible Links
  
• Ignition???
  

Check off what you have examined and found to be OK. Start with the easiest ones first.

BUT - Before you begin lets talk about Oxidation and our precious Z's. Anywhere there is an electrical connection there is an opportunity for oxidation to occur and interrupt the connection. Oxidation usually looks like GREEN filmy gunk down in the Injector connectors and on the TPS and AFM connections. You can clean this on the Injectors (and other Male Connectors) with the sandpaper trick that was mentioned earlier followed up with Deoxit and then Dielectric Grease. Cleaning every connector will be time consuming and tedious, but it will greatly improve all aspects of your Z's electrical systems.

On electrical connectors such as the Fuel Pump, Relays and Fuses the oxidation looks like brown tarnished metal. This is the stuff that causes increased resistance and failure of the circuit. Fuse Blocks and Lighting usually suffer from this.

From reading these posts, I really do not believe that you have a fuel pump issue but rather a component issue that is cutting the fuel (OR IGNITION) off. It has been mentioned earlier that the AFM has an Fuel Pump cut-off on it, that should be looked at. The Oil Pressure switch by the Oil Filter also controls some circuitry that can shut off the Fuel Pump. The ECU (Brain) controls the Fuel Pump Relay, a bad ECU could = dead Fuel Pump.

Have you thought about the possibility of you ignition shorting and cutting of the car? (sorry if you already covered that). Do you have a Timing Light that you could use to check for a spark when this problem occurs??

Have you checked the EFI 12v connection to the Battery (White Cable) to make sure that it is tight and in proper condition to the Fusible Links?

Have you checked the condition of the relays (Fuel & Ignition).

Sometimes the Wiring Harness where it goes through the firewall can develop a worn spot and then short and cause all kinds of mayhem.

When I worked over my Wiring Harness I replaced all of the Injector Connections with ones that I picked up on eBay. I slipped on heat shrink tubing prior to soldering the connectors, then shrank those on the new soldered joint.

If you want to keep tabs on the Fuel Pump, you could wire a Idiot Light to the circuit of the pump as was mention prior in this blog -

Well that is all I've got for you now. I have several ECU's and AFM's (in various condition) that might be used for testing purposes if you want...

Here is to the Good Fight and your Positive Attitude!

[Zed Head]

Another good material for cleaning oxidized, tarnished or corroded connections is 3M Scotchbrite. It's not as aggressive as most sandpapers and leaves a nice shiny surface with no grit. It will also hold up to WD-40 or Deoxit or a typical contact cleaner. You can cut a small piece and use pliers or a screwdriver to get in to small places.

argniest, I don't know what your weather is like, but if you can get the car out for a spin, you'll probably be more able to translate all of this new knowledge back in to a new description of what your car is doing. I went back to Post #1, and the original issue was that it was down on power and getting poor gas mileage. If you do too many things without re-establishing a baseline you can get lost.

I saw your comment about your headlights magically coming on again. That is a sign of oxidation in the headlight switch or in the dimmer switch, from sitting and not being used. From what I've experienced and read on these forums, the old "use it or lose it" axiom applies in full force on these old cars. The headlights on my car didn't work when I got it, but I haven't had a problem since I used some Deoxit to get them working and use them quite often now. Sometimes you can just spray contact cleaner in the switch and work it around to brake up that oxidation. Yours will probably stop working again in the future when the temperature and humidity changes unless you start using them regularly.

[FastWoman]

What Andrew and Zed said.

I forgot about the relays. There's a black box on the passenger side of the engine comparment, mounted to the inside of the fender. There's a plastic cover inserted into the backside of it and a few screws securing the cover. Remove the cover, and look inside. You'll see several relays there. You can pull the connectors off and clean them up.

I can't draw on too much experience here, but I THINK ECU failure is rather rare. Ztrain documents some cold solder joints in his that he had to re-flow, but I think his engine still ran. I've never heard of one flat-out going kapoot. I think may be rather common for them to fade away, but the engine should still run at some level. That said, I think fuel pump control is powered straight off of the ignition circuit, once the engine is running. I don't think the ECU is involved in any way except for sending the original 5 sec "start" signal. The fuel pump should keep running as long as the engine is running (assuming working alternator and oil pressure), irrespective of the status of the ECU.

I agree with Andrew! Kudos for toughing it out. Once you get it running right, it will be a very reliable machine -- along the "use it or lose it" lines, of course.

[argniest]

PS. I was asking some other questions in the forum, ....and someone asked me to post what I know about my engine/car. So here is a long list of what I can think of, off the top of my head

http://www.classiczcars.com/forums/showthread.php?p=350544&posted=1#post350544

[Jennys280Z]

What do you mean, if its oxodized? I am not sure what I am looking for when looking at each connector, to be able to be sure 100% if its oxodized. I certainly dont want to screw up a connector for no reason, and then have to worry about replacing it. I am not a solder guru, and would have to learn about that too. I have heard there are lots of wrong techniques for that kind of work.

So are you saying it was a bad idea to clean the EFI connectors at each fuel injector?

I already know my AFM has been *adjusted*. But there are sooooooooo many reasons right now that the car might not be running perfectly. I know some of them, and other reasons can be because of poor grounds and poor connections. And cleaning connections and grounds is definately something I can work through this winter.

Yes, I think its a good idea for me to clean all the recommended connectors in the engine area. And possibly other ones too. I read on this forum that a big whopping percentage of problems can be caused because of bad connections. Im talking about making a car run lean,run rich, and whacky electrical problems all over the place. So this has become a high priority for me to work on now before I do anything else.

And also, I am going to replace all my fuses in the fuse box with new fuses. Because some of them could be 33 years old. And they can do funky things too so I have read on this forum.

This website is a blessing for sure. Probably the best site on the entire internet as it turns out for me, because of some wonderful wonderful people here! I'm still on the tip of the iceberg here searching for treasures posing as discussions hehe

I cleaned every connection in the picture of connectors from AtlanticZ but "If it's oxidized" is a great question. For me it was immediately obvious just looking at the differences between the connectors on the fuel injectors for instance. I started out with #6 because that was the easiest one to get to and looked carefully at each connection. #6 looked like clean metal on first inspection. A light brush or two with sandpaper and it looked exactly the same. Nothing came off on the sandpaper. A big shot of Deoxit and then onto the next one. By the time I got to the last connectors the difference was huge. There was thick green oxidation covering both the male and female metal. So the idea was to get that off, and make the connector look clean like #6.

The connectors on the ECU looked so good I didn't do anything but Deoxit them. The connectors on the water housing by the thermostat were obviously gunky, as was my oil pressure sensor (my oil pressure rarely went past 0 before cleaning that - now it moves much more normally yaay), so I guess the unspoken method I was subconsciously using to do this task is to apply the minimal amount of friction force necessary to get the connectors clean. Probably a good methodology to start low and come up as needed. But you're right, you need a frame of reference like I described with the fuel injectors. It's a relative universe after all.

There's other connectors I want to clean that I haven't yet. I'm having a problem with one of my license plate bulbs now. The bulb was shot (filament was off) so I replaced it but it still won't come on. I see it attached to the harness but don't see any other connectors to clean. So I'm at a bit of a loss as what to do from here.

I build my own desktops so I have a bit of experience related to yours as well. But other than that, that's about it for handling electronic gizmos.

FastWoman is like a queen around here to me btw. I do whatever she says (unless I'm scared to).

[argniest]

Yes, I have been on the internet from the beginning almost. And this place is heaven for a Z owner like me, who wants to learn some things and do some things. Im glad there are patient and nice people willing to help I am so glad I found it. And yes, I am slowly working my way through everything that has an electrical connector in it. Especially everything in that diagram. And a few other things maybe...Im trying to use as little force as possible with everything that I do, but still make a difference. Worse case I just use dexoit if I dont feel comfortable with anything else.

a 30+ year Z guy told me about two connectors inside the car to clean also with deoxit. So I will be doing those once I get all the stuff under the hood done. Who has time to work, when you got a Z in the garage to work on he he

Edited January 18, 2011 by argniest

[argniest]

So can anyone tell me what kind of average gas mileage they get on their 1978 280z car?

Because of the multiple issues my car is currently having, its only getting 11 to 12 mpg when the plugs are fouled up. Once I realize plugs were that bad (and am now acutely aware of that situation), I changed them. And then I got about 17 or 18 mpg on higher speed interstate driving.

I am curious what the top 3 most common causes would be, for a 1978 z car to be sucking down gas like this? Is it just really thirsty If one of my mechanics friends hypothesis is correct, he is saying that fuel injector #6 basically isnt working. And therefor I am driving around on 5 cylinders. Which is not efficent and would cause the car to use more gas to push it around. And if the gas in # 6 cylinder isnt even burning, it might explain why I think I have a rich gas smell coming out of the tailpipe when the windows were down in the summer/fall....

Edited January 21, 2011 by argniest

[FastWoman]

Well, 11-12 mpg is horrible mileage. You might get as low as 17 or 18 on a properly running engine if you're running it a bit hard. If you're going a tame 55 mph, you might get somewhere in the mid/high 20's. I get about 20 mpg combined city and highway with ordinary, non-heavy-footed driving.

But no, these aren't the most fuel efficient vehicles!

[jackeyerly]

Hey you guys are all right! I mean it, everyone of you guys (and gals) are all right! Every one of you are just full of good information and ideas. Actual useful information and alot of just damn good ideas! You should all take a few minutes and give yourselves a pat on the back for being there for this and every other z car owner in their time of need. There is no doubt in my mind that this guy is gonna figure this thing out eventually with your help. Keep up the good work! All of you!