DIYEFI.org Forum

Fred,
I hope I've placed this in the right spot.

The Ford Profile Ignition Pickup signal is a square wave, 12 volt, 50% duty cycle signal, the rising edge of which occurs at the base timing angle set by the distributor. This base timing angle is normally set at 10 degrees BTDC, but not always. For instance, I found that I had to move it to 6 degrees BTDC on my 300 I6 to get around pinging issues, so there needs to be a user configurable offset available to permit different settings. Software would be ideal, but firmware would be OK.

My "superstim" simulator just uses a 555 timer to create the signal. When I do actual testing I have a TFI bench test unit that uses a TFI distributor, coil and plugs with a degree wheel that I drive with a variable speed drill. I use a timing light on the degree wheel to confirm that my commanded spark angle is what I'm getting at all speeds and loads.

Rob, have you tried to port over the outputs of a 1st gen magastim to your ems? Would it serve any purpose to megastim your jaguar for testing? Mind you the gen 1 megastim was just basically a timer circuit and a few variable pots. I ask because i have a cobbled diy megastim off a breadboard and it could at least tickle the EMS dist/dis input so i can watch the little lights flicker.

Pishta,
I'm not sure what you mean by "port over". As I mentioned, I have what I call my "superstim". I built it to test all the standard MS1 I/Os, the extra stuff I've added as well as my transmission controller. For ignition trigger I just used a 555 timer for a square wave 12 volt signal. To test if the SPOUT signal occurs at the crank angle I have commanded I have another gizmo. Just a TFI distributor, coil and plugs with a degree wheel mounted on the distributor shaft. I drive it with a variable speed drill and check the timing angle with a timing light.

port over just inferred that you would take the M/S labeled outputs of the stim and plug them into the jaguar inputs. Ie. o2 sensor voltage, IAC voltage, and M/S stim distributor signal to your jaguar. I suppose its all the same sort of signalling....I think the stim I have is a glorified 555 timer too with a few pots to adjust "RPM" of the 555 timer pulse.

Ah yes. That's what I am attempting to do but I seem to be having difficulty getting clarification on some of the connections.

Then stop porting, and start working from first principles :-p

Fred,
I'm sorry, but I don't know what you mean by "start working from the first principles".

E4ODnut wrote:Fred,
I'm sorry, but I don't know what you mean by "start working from the first principles".

Maybe "forget M/S, take outputs of whatever you can stimulator (home grown, spun Ford TFI off a drill or bought) and plug into Jaguar and see what flies..."

ie. on a MS stim V1, TPS (throttle position sensor) pin 22 out would obviously go to Jaguar TPS input above C37, CLT (coolant temperature) pin 21 out would go to Jaguar CHT (cylinder heat temperature?) above C35, O2 pin 23 would go to Jaguar O2 above R34, IAT would go to Jaguar TAT (T(?) ambiant temperature?) above R27, dist trigger pin 24 would go to....uh...and so on. Looks like I gotta do a little research too. With my crappy breadboard stim I could move most gauges in studio except 1, forgot which one but I was stoked I got something out of that ol' MS1-2. It sounds like your board is already past what my MS ever got to.

Actually the timer was based on an AD654 tickling a 2N3906 transistor with a 10K pot controlling the speed. but whatever you got to work....

CHT = Cylinder/Head Temperature
CLT = OEM abbreviation for coolant temperature, and FreeEMS has been designed from the start for air-cooled engines, too.

I'm considering changing it to something else, but haven't decided yet.

But yes, first principals = this pin on your OEM setup is for air temp, hook it to air temp, etc.