Aeromotive A1000-6 Adjustable Fuel Pressure Regulator

I chose to install an aftermarket adjustable fuel pressure for a couple of reasons. First, I have a hotwired Walbro fuel pump, which flows a significantly higher amount of fuel than stock. Under low load conditions, the stock fuel pressure regulator capacity is excceded, causing the fuel pressure to be too high, which leads to the engine running rich. Most importantly though, an AFPR allows for the base fuel pressure to be adjusted, which gives additional tuning capability to maximize the use of a given size of fuel injectors.

The following is a description and some pictues of my installation of an Aeromotive A1000-6 Adjustable Fuel Pressure Regulator (AFPR). Most aftermarket adjustable fuel pressure regulators will not connect to the stock fuel rail, and therefore adapters are required. There are several different regulators available, and many different manufacturers and parts for the AN hose, however these are the parts that I chose.

Description	Manufacturer	Part Number	Quantity
Adjustable Fuel Pressure Regulator	Aeromotive	A1000-6 (13109)	1
Fuel Rail Adapter	ek2 Development	"Triangle"	1
6AN straight hose end	Earl's	300106	1
6AN hose	Earl's	300006	1
6AN 90° hose end	Earl's	306106	1
6AN union	Earl's	981506	1
6AN Buna N O-rings (10 pack)	Earl's	176006	1
6AN plug (2 pack)	Earl's	581406	1
6AN x 4 AN union	Earl's	991906	1
4AN x 1/4" hose barb	Earl's	709104	1

Most of the information for the necessary parts, as well as the installation instructions were obatined from Stealth316 Fuel Pressure Regulator Upgrade. While I used that site for the general installation information, I chose to connect and mount my AFPR in a slightly different way, as described below.

Very little disassembly and preparation is needed for this installation. First, remove power from the fuel pump. This can be done by disconnecting a connector under the hood, at the fuel tank, or by removing a fuse. Once this is done, crank the car several times to decrease the fuel pressure in the lines (the car should crank and may briefly start, but should not continue to run). I removed the PCV hose that goes from the rear valve cover to the pre-turbo inlet piping, and a bracket that holds the spark plug wires in place. The fuel pressure regulator is removed by disconnecting the two bolts that hold it to the fuel rail, disconnecting the vacuum line to the regulator, and by removing the hose connection to the fuel return line.

I connected the fuel rail adapter to the fuel rail, and then began to decide on the placement for the AFPR. I connected the 6AN union and the 90° hose end to one of the inlets to the AFPR (don't forget to put an o-ring between the union and AFPR), and I connected the straight hose end to the fuel rail adapter. There was an available bolt hole near the thermostat housing, and I decided to use it for the mounting point for the AFPR. I used the mounting bracket that was included with the AFPR, and then used an additional short section of metal to extend the bracket so that the straight hose end connection lined up with the 90° hose end connection. Some bending, drilling, and grinding of the brackets were necessary.

Once the connections were lined up, I made the hose. I was unfamiliar with the fabrication of AN hose, and so a bit of time should be allowed for learning, if this is your first attempt. In all honesty, it is not very difficult, but it takes a few minutes to get the hang of it. The description on Stealth316 was very helpful.

I then placed the 6AN plug (which should already have an o-ring) into the other inlet of the AFPR. I connected the 6AN x 4AN union to the outlet of the AFPR (don't forget to put an o-ring between the union and AFPR), and then connected the 4 AN x 1/4" hose barb to the union. I already had a fuel pressure gauge installed, and so I relocated it to connect to the gauge port on the AFPR with the use of a 1/8" NPT 90° street elbow.

After that, put the AFPR into place, and tighten all of the connections. Reconnect the vacuum source to the AFPR, and reconnect the PCV hose. Reconnect power to the fuel pump, and then do a leak check. The easiest way is to use a datalogger, and energize the fuel pump relay from the test/diagnostic functions. Check for leaks. If none are observed, energize the fuel pump relay several more times until line pressure has built up. Check for leaks again. Once this is done, attempt to start the car. If the car will not start, adjust the fuel pressure higher and try to start the car again. Disconnect the vacuum source, and adjust the fuel pressure to the desired setting (stock value for a twin turbo is 43 psig). Reconnect the vacuum source, and check that the fuel pressure decreases. Be sure to check tuning with whatever method you feel comfortable.

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