Well, I'm updating my experience with the Holley Sniper installation. My project is a Toyota Land Cruiser (LC) with the venerable 2F straight six. That engine is almost a clone of the GM 235. I used the Sniper 2300 unit as it best matched up with the Toyota 2 barrel manifold. You only need few wires to hook up. 12+, switched 12+, coil/ignition signal, coolant temp and O2 sensor. All of the other EFI sensors are built into the unit, MAF, MAP, TPS, etc. The ECU is also integral to the Sniper assembly.The unit comes with fuel pump relay and a small lcd screen for setup/readouts, logging and software updates. The main issue is supplying high pressure fuel to the unit. The Sniper has an internal fuel pressure regulator (58.5 psi) so it needs ~60 psi. The next fuel system issue is a fuel tank return line. I was lucky in that the LC carburetor fuel system had a fuel return line installed from the factory.
I solved the high pressure fuel supply issue by assembling a DIY fuel surge tank. I used a 1.5 liter ebay surge tank and installed a Bosch 044 fuel pump. The LC mechanical pump supplies the surge tank and the Bosch 044 sends 60 psi fuel to the Sniper. The return line from the Sniper goes back to the surge tank and any overflow or excess returns to the fuel tank through the factory return line from the surge tank.
The Sniper coolant temperature sensor is a regular 3/8 NPT unit so that is not a problem.
You will need an O2 sensor. The Sniper comes with a clamp on O2 bung but I chose to weld a standard steel bung to the exhaust pipe. The location/mounting instructions are included with the unit.
The Sniper can receive it's ignition signal from a variety of systems. The one I used is to connect the Sniper to the coil negative post. That is the most basic of their install scenarios. They have ones for HEI, MSD, etc.
I hooked all of the above and entered the engine info into the Sniper ECU through the handheld/LCD screen. The setup includes cubic inches, stock, mild, wild cam, number of cylinders ,idle RPM, etc. The first startup was flawless except for a small fuel leak on one of the AN lines that I forgot to tighten fully. Other than that it came to life and idled smoothly.
I am currently just driving the LC around at various speeds and loads just to assist the Sniper through it's self learning process. I can monitor and/or set the target air fuel ratio (AFR) for various conditions through the LCD. I have noticed that if I repeat various driving conditions, over time the performance and AFR start matching up with the targets that have been set. I am a complete nooby when it comes to EFI tuning so I'm slowly digging into the various settings, etc. There is a Holley Sniper forum that is a great resource and the ability to log and upload your data logs to Holley support techs is pretty cool.
Overall, I'm very happy with the unit and it has completely changed the performance of the LC.
SimS
