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Projections actually work pretty darn well, it just takes someone who knows how to tune them to get them to work. 9 times out of 10, problems come from a lack of understanding and improper tuning methods. While it's no multipoint efi system, it is certainly better than a carb. Back in the early '90s I had some friends who ran roller cammed 401s that turned 7500 rpm at cranked out hp in the high 400s. Running in Tellico was fun, and these guys could tune a projection and showed me how to get my old analog dialed in on my 401. I can give you some quick pointers: you are going to need a voltmeter and a fuel pressure gauge. 1) Set the DIP switches inside the ECU to the small block setting 2) If you can hot wire the fuel pump do so and get it to run without the motor running.

With the fuel pressure gauge, set you pressure to 15psi. 3) Set the adjustment screws to the middle location.

4) unscrew the idle screw on the TB all the way out so that the blades close all the way, then screw it in about 2.5 turns. Set the voltage across the TPS to.63 volts. While the voltmeter is hooked up, open the throttle all the way and it should read about 5 volts at WOT.

Now is a good time to make sure you have a steady rate of increasing and decreasing voltage as the throttle is opened and closed. You don't want any interuptions in the reading which would indicate a faulty TPS. 5) start the motor. It should be set close enough to idle.

If it won't stay idling, or if it's idling too fast, adjust the idle screw to where you want it (about 700-800rpm). You will have to readjust the TPS to.63V if you change the idle speed with the set screw. Also verify you are holding about 15 psi fuel pressure at idle. If you blip the throttle, fuel pressure should stay close to 15 psi. Yamaha Dsp Ax1 Manual more.

6) Now you can tune the screws on the ECU. It helps if you understand that setting the TPS sets the total range the tuning screws will affect. The TPS voltage setting moves this range up and down the rpm scale in one big block. Each indivudual screw (idle, mid, power) controls the fueling through the three main areas of throttle usage. Idle controls any fueling at idle speed, midrange control the cruising fueling up to about 2/3 throttle, and power controls anything over that.

With that being understood, it's best to start by adjusting the idle speed and set the screw where you get the highest idle speed, and then lean it out a little. Next, while sitting still, rev the engine to 3000 rpm, and then turn the midrange screw until you get the highest engine speed while holding throttle at the exact spot you started at 3000 rpm. Now you should be ready to drive. The rest of the tuning (power, accel pump, choke) are done just by driving the vehicle. The power screw controls full throttle fueling and generally, that can be leaned out quite a bit. Accel pump- well just set that to where you can nail the throttle from idle and not get a spit back throught the TB or smoke from the tailpipe.

Choke is set with the engine cold. It simply controls how long the high idle will stay on.

It's a very basic system and is pretty much controlled by potentiometers. The TPS sets the window, and the screws dial in the three ranges. Fuel pressure should stay about 15 psi at all times, and it's imperative that there be no fuel pressure on the return line- it must read 0 psi at idle. Yea, it took me forever to get it figured out, but once I did I was very happy. When I moved to the Durango area I was able to drive from there to the highcountry and only have to give the midrange a slight tweek to lean it out when we went above 9000 ft.