76 280 spark plugs?

[FastWoman]

Kacrow, I bought a set of the Standard Ignition injectors (probably the ones you're looking at), and they've worked fine for me. I have third-hand knowledge of some people (don't know who) having some issues with those injectors. Some people have their original OEM injectors reburbished and flow tested, but I've read of too many of those injectors leaking for me to think this is a good approach. The only thing about the eBay Standard Ignition injectors is that you'll have to cut off the shorter hoses and attach longer ones. This has to be done very carefully, so that you don't nick the aluminum barb underneath (which would cause a leak).

Before you replace all your injectors, you might want to see how they're spraying. To do that, you'll need to undo all 12 injector screws and the retaining bolts on the fuel rail, and pull the whole assembly out, injectors and all. Then lay out a lot of newspaper over the top of your engine, and set the fuel rail down on it. Crank your engine, and see what sprays out. You should get one quick spritz from each injector (all at the same time), once per engine rotation. The spray pattern should be healthy (a nice mist), and each injector should spray the same amount of fuel. Then after you stop cranking, make certain none of the injectors dribble.

Before you go any further, go to xenons30.com to download a free copy of Nissan's factory service manual for your car. With the FSM, you'll be 5 times smarter than you are now -- guaranteed!

Oh, and please don't get turned off to this list. These is a great list with some really friendly and helpful folks. We do like punctuation and capitalization here, because otherwise it takes twice as long to read a post. However, we're pretty forgiving of rough starts. Hang around, and we'll warm up!

[Threehz]

Just as another source, www.rockauto.com has a variety of fuel injectors including Standard, which are usually 25$ an injector, they also have another brand for around the same price, then a bunch of other brands that go up from there. FWIW

Good luck getting her running!

[grantf]

listen to Fastwoman. But hold off on buying injectors till you have sorted out all of the systems. I was close to replacing mine before I found numerous faults elsewhere. At first the EFI system seems complicated but when you go through it systematically it will become clear how everything works. Here are some things I will throw into the bucket (but I do not wish to throw you off).

what condition is the dizzy in? there must be a reason for different plug readings.

replace and examine all vacuum lines, it is cheap and can familiarize you with the system a little.

electrical conections are VERY important in an EFI system, Check and clean them before testing

there are some components that have failed on my car that were culprits that are cheap or even free to repair and easy to test (water temp sensor and TPS come to mind)

Spend some time looking over the EFI bible and the FSM, it helps to understand.

And click the ABC check I do it all the time so arses that think they are smarter than me don't stab me for a freaking typo.

oh and welcome to the best Z site on the planet.

Edited October 21, 2011 by grantf

[kacrow76]

Ok so i checked and replaced all of my vacuum lines and it idles a lot better.All of the injector

connector's are missing the little wire clip's so this tell's me that someone has missed with them i did clean them as best as i could.When i first start it up it run's ok and i mean just ok but once it get's warmed up it, it has no power past 3000 RPM's it falls on it's face. I hate to do it but i think i will replace the injector's and connector's.I also think i might check the water temp sensor.I did clean it's connection. Thanks for all your help

[240260280z]

3000 rpm "rev limit" is often caused by the throttle velocity switch on the side of the throttle body. Usually it has water in it that shorts connections OR the wiring to it has a short. A quick check to see if it is working is to simply unplug it and see if you get past 3000 rpm. Here is a reference. http://www.atlanticz.ca/zclub/techtips/tps/index.html

The bad clip mechanism on 280z's is the cause of many fuel injection problems. Usually soldering newer connections with better clips (from a junkyard acr) is a good upgrade. To test the injector signal, simply plug a 12V light into the pins and see if it lights when the car is running. You can also swap the connectors between adjacent injectors to see if the problem moves. You can also listen to each injector with a long screw driver on it and pressing the other end against your ear. All should sound the same and have a metal click. You can listen then unplug and plug in the connector to hear the click start and stop.

Some info here:

http://www.atlanticz.ca/zclub/techtips/injectors/connectors/index.html

http://www.atlanticz.ca/zclub/techtips/injectors/index.html

[240260280z]

Here is a layman's overview of the EFI system to help you get a foundation of what you are dealing with. It is not really that complicated when you break it apart:

http://www.atlanticz.ca/zclub/techtips/efisystem/overview.html

[FastWoman]

If your connectors otherwise look good, which I doubt, you can bend new clips out of small paperclip wire. If you decide to replace them, f0rrest on eBay sells nice sets. You might want to do ALL of your connectors, especially the ones on the front of the engine (thermotime and coolant temp sensor). There's a total of 10, but you might want to get an 11th one to have on hand for testing purposes.

By "no power past 3000," do you mean the engine won't rev past that point? If so, it sounds like a problem with your throttle position sensor or its connector.

Running OK on startup and then running worse on warm-up sounds like a lean-running condition. When your engine is cold, the mixture is enriched, and then when it warms up, the mixture is leaned out. The good news is that your coolant temp sensor is probably doing something to make that happen. It might still be off, though. You need to measure its resistance. You can tell the most about what's going on, electrically, by pulling off the ECU connector and going through all the electrical tests laid out in the FSM. They have a great diagnostic guide.

[Zed Head]

It could be fuel pressure. Steady fuel pressure at the factory spec. is necessary for the ECU to do its job right. Even if the pressure looks good at idle or tested with the engine not running, sometimes the fuel pumps will lose pressure at higher flow or when they get warm. Knowing fuel pressure is one of those things you have to do.

I recently picked up a brand new pump (shiny) from the wrecking yard and it only lasted about 20 minutes while I was testing it at home. It had had some water in the fuel lines (gallons according to (the yard guy said 4 gallons came out of the tank) and must have rusted the guts of the pump (luckily they threw it in with the spare engine I was buying, so no real loss).

It may seem like a waste to buy a pressure gauge for $40 only to use it once or twice, but you can save a lot of money in the long run. Many people recommend hooking up the gauge, running the hose out of the hood where you can see it, and taking the car for a drive while you watch it under load at higher flow. Pressure should not go much outside 30 - 38 psi while you're driving.

p.s. Just re-read my other post and it seems harsh. Sorry about that. Good luck with the car.

Edited October 24, 2011 by Zed Head

[kacrow76]

Wow now i only have about five thing's to check. you people have been great help. I will check the TPS and fuel pressure tonight. As soon as i turn the key on i can here the fuel pump and it will run until i start the car seams like the pressure will not stay up. but the fuel pressure check should let me know. i built my own gauge not sure if it will work but it should.Thanks again

[FastWoman]

IF you can't hold fuel pressure after you've shut off the ignition, it could be the check valve in the fuel pump, but it could also be worn/crudded-up/dribbly injectors, which would be consistent with your initial concerns (spark plugs all looking very different). I'd say if you drop 10 psi over 10 min (just grabbing numbers here), you've got a significant leak. It could be from the fuel rail into the intake manifold, or it could be from the fuel rail back to the tank -- or both.

[kacrow76]

Ok the Z ran better tonight then it ever had.cleaned the TPS and set it not sure it was off that much but the connection was bad. Fuel pressure with key on it runs up to 40 psi then on start up drops back to 31 to 32. After it sets for some time one hour or less It drops to nothing or 0. Not sure what it is while driving will have to take the hood off to check that.I have a lot more power but if I try to run it up around 3700 it starts to run bad again.I am getting there. Thanks to all of you.

[cygnusx1]

I feel this is a great opportunity to promote downloading the original factory service manual. It's a great read, very interesting, and probably the best "time investment" you can put into your project. Especially since the car is staying in the family.

http://www.xenons30.com/reference.html

Enjoy the read! EVERYTHING you need to know is right there in black and white.

Edited October 25, 2011 by cygnusx1