ECM Test Bench

[rts91tsi]

You all have some excellent test bench setups! I have been interested in setting up a test bench for a while, and was unsure how exactly to go about doing so, until I stumbled on the JimStim info in the TunerPro thread. It is great that there is such a tool available, and I plan to not only use it to verify ECU repair work, but also use it to try to further modify and verify code modifications.

Before I learned of the JimStim, I was planning to use a spare engine wiring harness and some sort of multiple DC voltage power supply, and who knows what else, to create a test bench of sorts. Hell, I even though of using a battery operated Tens Unit to create electrical pulses to mimic the sensors that use those types of signals.

For those of you using batteries for power supply, have any of you tried using the power supply listed as an accessory?

[EagleMark]

I used the optional power supply for the JimStim and it worked fine. But didn't need it as I have a 12 volt lawn mower battery I use for powering the other entire system. That has a battery tender, like a trickle charger to keep it charged.

If you look at that picture in TP thread IIRC Mark has a electronics power supply...

[Six_Shooter]

I use a 5amp 12volt power supply. I plan to add a battery, but to be more of a filter, than something to power the system from.

[EagleMark]

Exactly why I use a 12 volt battery!

Electrical noise from Ignition Coil, spark plug wires etc... has to be looked at carfully whe doing a conversion. First one I did with front distributor, (Chevy has rear distributor) had issues! Found them with my Osiliscope and changed wiring path of harness to fix the noise! Actually I moved the coil!

[rts91tsi]

I see what you guys are saying about using a battery as the power source, instead of the plug in wall unit. Since the wavelength of the AC current is broad, its output would be more inconsistent than a true DC power supply. An electronics power supply, oscilloscope, and a meter that can measure capacitance are definitely on my list of things to eventually add to my bench setup, but for the time being, the basic necessities will have to do.

[1project2many]

The "no longer available" stimulator looks like one designed by (I think) Bob Ward? He was on thirdgen last I knew. If my memory's any good he had an old Malibu with twin blowers from a junkyard. He said he built that after looking at my test bench and deciding there was no way he wanted something so big and clumsy.

At the time, I thought mine was pretty organized. I used an ignition module from a small cap dizzy to drive a small LED so I had visual confirmation that the RPM generator was working. I picked up a GM test tool from a swap meet which outputs various frequency A/C signals for testing DRAC, instrument clusters, &etc. For most of what I was doing I found a fixed RPM input was satisfactory. I've also seen people use cable driven magnetic VSS connected to an igniton module as an rpm input. I used pots for sensors and put LED's on several of the outputs and on the REF and EST lines. Having trouble finding pictures but then again, I haven't had it out for at least 5 years. Here's the DIS system I set up for testing:

disrig2.JPG

It's an old PC fan with notches and a crank sensor connected to an actual DIS module. A dial back light was useful in measuring delivered timing to confirm chip settings. A PC power supply for the bench worked well for most testing but the DIS module with coils attached required more current so I had an automotive "jump pack" attached along with the power supply.

[RobertISaar]

i'll have pics up tomorrow. :D

mine is currently functioning.... kinda. i'm having issues with the 3 wire sensors ATM, but i have a good idea as to why. turn A/C pressure pot, skews MAP and TPS readings... what a pain.