D-Jet Bench Setup, Let the experimenting begin (again).... Options

[pbanders]

See attached photo, this is my D-Jet bench setup. The black box on the left is an EFI Associates 1400 D-Jet tester (circa 1972) that measures the injection pulse width, simulates the trigger contact points over a range of engine RPM's, and provides reference values for the CHT and air temp sensors, as well as the throttle switch operation. The ECU is an 044 that I've used in the past for all of the oscilloscope traces on my web page, I can access any circuit in the ECU with it. I've got a TPS connected to the harness in the middle of the picture, as you turn it it you can watch the injection pulse width increase, then when you stop, you can see the pulse with relax back down (there's a delayed effect as well as an immediate effect). I have an air temp sensor plugged into the harness, and instead of a CHT, I have a variable resistor (half of a pot) that lets me simulate the engine temperature. That's a NOS 043 MPS in the upper right, with my vacuum pump attached to simulate engine load.

I've also got an interposer box that I can put between the ECU and the wiring harness that can be installed into the car so I can monitor all of the ECU pin connectors while driving the car. My current box is a PITA to use in the car, my old design sucks. I've got an idea for a better one that I'm going to have to build.

I've also got a Fluke calibrated pressure sensor that I can independently monitor the manifold pressure, or the pressure at any other point in the vacuum system. I can datalog the output from my DMM to get any of the pressure values as a function of time.

Now, just gotta do something useful with it all. BTW, working on the 914 is one of about a million things I'm trying to do simultaneously, so I tend to get to it irregularly, just hoping that's more than "never". I plan to look into the hot start problem first. I'm going to take some data when it happens on the car (i.e. measure the voltage at the CHT through the sequence of events), bench simulate it, then try to come up with some simple solutions. The idle stabilizer will take longer to do.