[shit – found this old post from 9/20/15 in Drafts (yes, two years ago!) with a bunch of pics but no write up. Well, let’s do it then! You’ve got time for Daily Datsun, right? Thank you! Let’s read on!]
As you’ve guessed from the title, we’re replacing fuel injectors!
After purchasing a classic Z, or any old car for that matter, there’s always a list of things to inspect, test, and replace. After what’s now coming up on…3 years (oh my!), I’m finally diving into the engine – specifically, its ignition and fuel injection.
The injectors in this Z have always been unknown to me..well frankly because I didn’t take the time to inspect or get to understand them. They clearly look like they were replaced by the previous owner (Wild Bill’s brother), they worked, it ran, and that’s all I needed to know.
But whenever I looked at those electric signal connectors fastened by a wad of silicon glue, it always made me wonder what the heck was going on. Until now I’ve been in the ‘if it ain’t broke don’t fix it’ camp, but one day, I had the gumption to poke at it while the engine was running… Immediatly, the engine started choking, gasping for fuel. You know, it’s about time we give it love and clean these up!
Let’s get our hands dirty!
What you’ll need:
- 280z Fuel Injectors – I went with the FJ707 fuel injector from Standard Motor Products
- Fuel Injector signal trigger – (I don’t know the real name for this but that’s what I’m calling it…) Standard Motor Products SK25
- Long Philips screwdriver, PH1
- Razor blade
- Rag to catch the gas
- M5-.8, 30mm machine screws (optional)
- Easy-out (optional, but i highly recommend SpeedOut or Aisxle )
- Hammer (optional)
- About 1-1.5hrs
Remember those FJ707 fuel injectors I bought a while ago? (7/25/2015)
Tip: Before diving into any project, it’s good to understand what’s the current state, or steady state – basically, what the heck is going on. I listened to how things ran, did a quick inspection of bolts, and made a mental note of where everything was (of course I made a digital “note” with camera too!). Are bolts rusted? What other parts are in and around the area that may need replacing? It really helps to visualize what you’ll be doing BEFORE you go and do it.
On with it!
Prepare to use a long Philips screwdriver to take out the screws holding in the fuel injectors. Or I suppose a right angled driver could work too. A long Philips will help get passed all the fuel rail business.
I didn’t have the right angled Philips but this extension I had lying around did just the trick.
Start by removing the screws that hold down the portion of the fuel rail above the injectors you’d like to replace.
Loosen up the hose clamps that connects the injector hose to the fuel rail. Getting the old injector hose off can be tricky. Just use a razor to cut a slit length wise where the hose meets the fuel rail. CAREFUL! Gas is going to leak out, so get that rag ready and handle it properly. You’ll notice that the fuel rail is separated into several sections. This is perfect because you won’t have to remove the whole thing to change the injectors out. I loosened one end of that sectional hose in the rail just to relieve stress and give the rail some flexibility. Now you can change 3 injectors at a time.
Note the silicon glue / electrical tape holding the injector’s signal trigger…
I started with the set of three closest to the cabin. Of those three, it’s easiest to start disassembling from the cabin forward, and then when re-assembling, start with the one farthest from the cabin. It easier this way because the motion of the fuel rail as you’re working on each injector can pop off the assembly of the previous one…you’ll see.
Here you’ll see the old injector on the left and new one installed on the right. When disassembling be sure to remember the sequence of parts and process.
Here’s the old injector with flange, gasket, and seal (cut). The rubber seal maybe all worn out and stuck to the flange or injector. Just cut that sucker off. I also used a hammer to get the flange off of one of them. Light taps!
Use the wirebrush to cleanup the parts.
The gasket was a bit out of shape when we pulled the assembly apart…
Our buddy Christian working the metal gasket straight.
Ugh stripped head. That’s what you get with a 38 year old bolt – rust and dust! I use the Speed Out easy out (Amazon) for all stripped heads – they’re amazing.
Replaced it with a stainless M5-.8 bolt, 30mm long from Home Depot or Amazon. You’ll notice the head a touch larger, bolt a bit longer, but it works just fine. Make sure to pick up new lock washers while yer at it.
Reassemble everything and that’s it! I think you’ll know if the injector isn’t working properly – the Datsun’s engine is pretty transparent, you’ll notice the misfire.
Next up: Shocks? Bushings? Hey, how come in one picture I see some blue wire in the background?!