[EFI-Unlimited]

...what i was getting at is that IF the ecu was still kicking out dwell even when configured correctly for edis that it would screw up the advance...

If this was possible, it would be true, but it is not possible. It has to be one or the other. It can't be both.

To everyone working on this, I want to be clear I'm not trying to pee in anyone's Cheerios. I own two 94 Mustang GT's and I would love to figure this out and make it work. I attempted this years ago (2002-2003ish?) and didn't get very far in making it fully functional. If we can figure it out, I will be next in line to try it.

Brian
EFI-Unlimited

[vristang]

All of this also doesn't address that problem of the SAPW being a 5v TTL signal. In order to produce this, you will need a 5v pull-up on the spout line (which nobody has mentioned yet...). Doing this will effectively invert the signal as viewed from the CPU, which likely will need consideration as well.

EDIT: The spout is a tri-state capable +12v output. A 5v pull up on the spout line won't work. Potentially, you could use a voltage divider on the SPOUT signal, or use the 5v pull up in the TFI coil output. Either are possible solutions to electrical compatability.

would you mind elaborating on how to implement both of these options?
I'm envisioning a resistor configuration as the divider, but no idea on the pull-up...???

[decipha]

the ecu is capable of doing so it juat needs to be configured correctly, if all else fails u can swap strategies and make it work so dont be discouraged but it just seems illogical that all the other ecus of the time can support edis yet henry went out of his way to remove it from only this strategy, if i wasnt workin from 5 - 8 everyday id be out tryin it just to see

[vristang]

Brian & Mike,
I don't mind a little piss in my cheerios, if it makes my car run better...
so don't worry about offending me

I'm not discouraged... just eager to find a resolution and get this heap running the way it should.


I want to make sure I understand the issue, so please confirm the following or make corrections if I am mistaken.

EDIS pin3 (SAW) runs to ECU pin36 - this used to be the SPOUT signal
In standard TFI configuration, the CBAZA ecu outputs a 0v to +12v square wave SPOUT signal
The edis module is expecting a 0-5v square wave as the SAW.

This 7v difference is confusing the EDIS?
Is it just a voltage difference or are there other differences in the signal square wave?



To resolve this issue the options are as follows...

1. Electrically modify the signal coming from pin 36. It sounds like there are 2 options?
2. Hack some code into the CBAZA strategy to change the pin 36 output.
3. Use a strategy that will allow the correct pin 36 output.
4. ???


I'm just trying to get my mind wrapped around what is going on...

I thank both of you for the responses...
jason

[EFI-Unlimited]

This 7v difference is confusing the EDIS?
Is it just a voltage difference or are there other differences in the signal square wave?

To be honest, I am only, "fairly certain" about the voltage difference. I haven't scoped it myself to confirm.

It is unclear whether the voltage difference is truly a problem or not. Possibilities range from, "the EDIS module can accept 12v just as well as 5v", to, "12v will damage the circuitry in the EDIS module". Unfortunately, the only way to know, is to try it out.

Additionally, there are differences in the signal, more than just voltage. These differences hopefully can be made up for with appropriate software switches.

To cut the spout signal to 5v, you can use a resistor divider network, or a resistor and Zener diode. I would recommend the resistor and Zener diode, as it will clip the voltage to 5v, regardless of the input voltage. As recently as two weeks ago, I purchased the necessary parts for this at a local radio shack, so, getting these parts isnt hard. A 1k resistor and a 5.1v Zener should do the trick. Arrange the resistor in series on the spout line. Connect the Zener to the EDIS side of the resistor on the spout line and the other end to gnd. If you get the polarity right, it will clip to 5v. If you get it backwards, it will clip close to zero volts.

Brian
EFI-Unlimited

[vristang]

Well, I haven't checked it, but I doubt my voltmeter will be able to tell if it's 12v or 5v or ?v...

I will stop at the radio shack in town and pick the stuff up though... should be cheap too...


Thank you!

[vristang]

Home town radio shack was sold out of 5.1v Zener diodes, will try again tomorrow.

[vristang]

Just to keep you guys updated...

I sent Derek an pm yesterday.
He confirmed that the CBAZA does in fact lack the code for calculating SAPW.

He isn't sure if the SPOUT signal and SAPW signal are compatible though. It may be that the EDIS can accept either.
They may both be the same too...

At this point it seems we need to scope ecu pin 36 to know what kind of signal the ecu is outputting for both TFI and EDIS configurations?

I don't have access to a scope for personal use...

[cgrey8]

Depending on how badly you need a scope, you can usually buy O-scopes, even USB-based O-scopes off eBay for fairly affordable. I've often wanted to get one, but just haven't had the specific need for one yet. Just keep in mind, you'll want an O-scope that includes at least 1 probe and also has a square wave generator in it so you can calibrate the probe once it is connected.

[vristang]

Depending on how badly you need a scope, you can usually buy O-scopes, even USB-based O-scopes off eBay for fairly affordable. I've often wanted to get one, but just haven't had the specific need for one yet. Just keep in mind, you'll want an O-scope that includes at least 1 probe and also has a square wave generator in it so you can calibrate the probe once it is connected.

I've seen some of these.

Think either of these 2 would suit my needs?

http://www.amazon.com/BrainyTrade-DSO-N ... d_add_1_dp

I've also found pc/laptop versions which look interesting... if more expensive...
http://www.oscilloscopesusb.com/hantek-dso-2090

[cgrey8]

The only "small" Oscope I've ever personally used is the USBScope50 which from what I understand still sells for a fair amount. It's a USB based scope that uses your computer as the display and is only 1 channel. So I expect these newer offerings you are finding are actually a better deal.

But I do recall that it was around 75MHz and that was considered the low-end for Oscope frequencies. One of those that you posted indicates its only 40MHz. That may be plenty for what you are doing, I don't know. But I thought I'd mention that.

[decipha]

have u checked out the handheld scopes off ebay for a couple hundred

regardless, if derek says it lacks the code then its useless as it wont work, even IF you accurately were able to replicate the signal the timing event would be off and it still wouldnt work

that sucks and its stupid henry did that just doesnt make sense

i feel guilty as i incorrectly misguided u, but fear not as decipha is here, if it comes down to it, i can send u a stripped d.e.c. that will convert the signal correctly for u so regardless dont sweat it but thats if it comes down to it, i shot derek a msg a lil while ago so i can do some testing when i get home tonight hopefully

[gt40ford]

cheap table top scopes can be found at craiglist or many from members of a ham radio club

[vristang]

have u checked out the handheld scopes off ebay for a couple hundred

regardless, if derek says it lacks the code then its useless as it wont work, even IF you accurately were able to replicate the signal the timing event would be off and it still wouldnt work

that sucks and its stupid henry did that just doesnt make sense

i feel guilty as i incorrectly misguided u, but fear not as decipha is here, if it comes down to it, i can send u a stripped d.e.c. that will convert the signal correctly for u so regardless dont sweat it but thats if it comes down to it, i shot derek a msg a lil while ago so i can do some testing when i get home tonight hopefully

Been looking around ebay for scopes as well... I think the first one I linked to above is the one I'll get, if I get anything...

No guilt needed dude. This is part of the fun/challenge.
There is absolutely no way I would turn down a peek at any version of the d.e.c.... so feel free to ship anything you want out to arlington WA.


For now, Derek suggested another strategy, so I started a thread on it. diagrams, vehicles, catch codes, etc...

Thanks for all the help here guys!!!
jason

[vristang]

Well, maybe there is still hope...


I wired in the resistor and Zener diode the way Brian had described, and switched ign_type back to TFI.

Took it for a drive and... that is the best the car has run since installing the edis setup.

I don't think this is conclusive, but it is suggestive.


Other than the voltage scaling (5v vs 12v), can SAW and SPOUT be confirmed as being equivalent?

[sailorbob]

SPOUT and SAW are different.

In non-CCD ecu's (dwell is controlled by the TFI module) the SPOUT is a 50% dutycycle signal and the rising edge of the signal fires the coil. In CCD ecu's (dwell is calculated by the ecu) it's dutycycle is varied according to the dwell time required and the rising edge of the signal fires the coil with the falling edge ungrounding the coil.

The SAW signal is a variable dutycycle signal too but it's duration tells the EDIS module when to fire the coil as opposed to one of it's edges. The SAW signal is delivered typically somewhere between 10 - 20 degrees ATDC. Dwell is calculated by the EDIS module.