Upgrading your 25 year old fuel injector harness is an easy to do project.
It takes very little time to complete and the cost isn’t bad to get the proper voltage to your fuel injectors.
(along with several other benefits, according to the stats on Racetronix’s site).
[and, you take a load off of your original wiring harness when using the relay hot wire].
You could probably make a DIY relay system for the hotwire kit portion (not the actual injector harness), but honestly, for this extra added item (ONTO the F/I harness), why bother?
You’ll have to cut into the original wires (because it’ll be difficult to find the correct electrical connectors to make it a simple plug n play), buy & hook up the relay, etc., etc.
Instead, for about $35, Racetronix sells the fuel injector hotwire kit, complete, ready to plug in and use.
Not to mention that it’s really nice looking.
For about $100 total ($65 for the harness & $35 for the hotwire) & a half hour of your time, you’re done.
An upgraded harness like the one Racetronix sells comes plug & play with the correct connectors & easy instructions.
For this 87 Buick GN, we acquired the fuel injector harness and the hotwire relay kit (separate items on Racetronix’s website).
You could just replace the harness alone (say, if yours is broken/old/wires are flaking/etc.), but while you’re at it doing this upgrade, might as well go all the way and add on the relay system, which supplies direct battery power (via the alternator) to the fuel injectors.
It’s kind of pointless to ONLY replace the harness section.
How to do:
1. disconnect battery.
2. disconnect each injector plug, by pushing in the metal bar located towards the bottom, then pulling it up & off the injector.
Cut the zip ties that hold it to the fuel rail.
(you may need to unbolt fuel rail if the injector wires are wrapped around the rail).
Keep going removing the wire harness until you get it completely disconnected all the way up to the main connector.
{the main connector is under the coil pack, and runs off of the wiring harness that is located on the back side of the engine, near the firewall}
3. disconnect the main connector from the injector harness.
Toss old harness aside.
{if it’s in ok condition, off it to offset the cost of the new harness!}
4. Take the new harness & connect each injector plug onto the proper fuel injector.
The plugs are embossed with the correct cylinder number for where exactly they go.
Push the metal bar in, snap onto the injector, then release the bar & it locks into place.
(check it by pulling up gently on the plug to make sure it’s secure).
You should again ziptie the wiring onto the fuel rail (this keeps the wires out of the way & looking neat in your engine compartment).
Eventually, you are going to run the main connector underneath the coil, but for now, don’t plug it in yet.
5. The injector hotwire kit has a few connections you need to make.
Take the black ground wire (with ring terminal connector) and connect it to the engine block (an intake bolt is ok).
Hook up the red ring terminal (marked +) on the back of your alternator.
Make sure there’s a 30 amp fuse in the fuseholder, then mount it somewhere convenient.
Now mount the relay somewhere convenient.
(it’s going to be near the fuse holder since there’s not much wire between these 2, so plan ahead!)
Take the cylindrical tube connector and connect it to the same type of connector that is on the new harness (near the main connector).
One end (male from relay) goes on the female (from inj harness), then do the opposite with the other 2 connectors to complete those connections.
{the long cylinder connection is the main power wire (feed) to the injectors}
6. connect the main connector of the new harness onto the main connector from the cars wiring harness.
Then stuff all those items underneath the coil pack.
7. Reconnect the battery.
8. That’s it, it’s completed!
Start the car, if it runs right, everything is good!
{if not, recheck all of the wiring connections; check the fuse; make sure all plugs are seated onto the injectors}
.
{this whole job may be easier if you remove the coil pack & ignition module first, as you can then (disconnect & install) all of the wiring at once & get to the main connector a lot easier}
.
