HKS Gen3 Fuel Rail, Greddy 720cc Injector Install

reddy 720cc top feed injector. Part# 1350072

On the right are the fittings that come with the HKS Fuel Rail. Insulator, bung/adapter, o-ring. NOTE: The picture also shows an o-ring and insulator on the left (top) of the injector, but those are not included with the kit.

On the left you see the o-ring and insulator.

The insulator part# is 23291-41010

The o-ring part# is 90301-07001. I’m not sure if this is a Toyota part. I got mine from Horsepower Freaks.

All assembled, ready to install into the rail.

Another angle.

o-ring and insulator.

Those 4 o-rings don’t stay on the bung/adapters very well, so you have to be careful when installing into the intake.

Ready to go.

Remove everything that’s in the way of the injectors and rail.

Here’s I’ve started soldering the new clips for the greddy injectors onto the wiring harness. It doesn’t matter which way the two wires go on each injector.

Soldered and taped up.

Removing the fuel system from the filter to the return rubber hose. Here’s the fuel filter top coming off.

The bottom left arrow is the rubber return hose that I re-used. The top middle arrow is pointing to the feed line to the fuel rail. The right most arrow is the return from the rail, and turns into the rubber hose on the left.

Removing the fuel rail. There are 3 bolts that hold it to the head, and a hose connecting the Fuel Pressure Regulator to the Intake Manifold.

Here it is removed.

On the left you see the hose that connects the FPR to the Intake Manifold.

New rail fitted. It took a while to figure out how to get it in without losing the rubber grommets. I had to pull the engine electrical harness up which sits above the fuel rail, it was in the way. Then, I installed the rail and injectors as one unit, keeping an eye on the rubber grommets at the end of the injectors.

Measuring the length reguired for the new lines.

Installed the FPR. I was going to install it on the return end of the fuel rail, but it was going to be a little tight. This new position may be permanent, but in case I want to move it, I made the return line longer than necessary.

Here’s the new line connected to an adapter on top of the fuel filter.

The feed line. It connects to a -6AN adapter that HKS supplied with the rail.

The return line from the fuel rail. I used a 90 degree fitting here connected to another adapter that came with the HKS fuel rail kit.

Secured the new line.

The arrow is pointing to the return from the HKS rail, which goes behind the FPR, and connects on the left side in this pic.

The arrow is pointing to the stock rubber return line (to the fuel tank) which I managed to re-use as a return.

All done. I then tested for leaks by jumping +B and FP in the diagnostic box. Success!

This documentation in no way replaces the Toyota MR2 Repair Manuals. The purpose of this content is only to provide supplementary information to fellow MR2 enthusiasts. Midship Runabout and its contributing authors will not be held responsible for any injury or damages that may occur as the result of practicing any of the methods or procedures described within this website. Article and photo submissions are property of the contributing author.

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