No SAW change V3 n EDIS

[SidWell]

I am getting no ignition advance on the SAW pulse. I have gone thru my hardware configuration per step 50 of the assembly instructions. All looks good. I look at the PIP and SAW signals with a dual trace scope. I do not see any change in the SAW square wave. It all seems a little out of whack when I compare it to the EDIS setup document. I have the MS configured per the EDIS configuration in the setup doc. When I look at the timing with a timing light, it shows about 9.5 degrees. I am able to coax the engine up to about 2500 RPM but the ignition does not advance. When I disconnect the SAW from the relay board, I see no change in the ignition timing. Any Ideas on how to get the SAW active?

 

The PIP and SAW share a common shielded cable. Is this a problem?

The PIP looks more like a lazy sawtooth than a sharp square wave.

I see the tach signal is working because it shows up on the Megatune.

[Matt Cramer]

Could you post your MSQ? I'm suspecting a settings issue.

[SidWell]

Matt, I hope you are right. Here is the latest msq file zipped up.

MegaSquirtMSQ.zip

[z-ya]

The PIP should be a nice square 12V waveform. Sounds like you have a capacitor on the PIP input to ground. You probably have C30 and C12 installed (Dave and Ed caps). You don't need them for EDIS. Which output are you using for SAW?

 

The SAW output duty cycle does not vary all that much. The range is from 64 - 1792us (57.5° BTDC to 10° ATDC). So you get about 60 deg of advance controlled over a 1700us range. So about 28us per degree.

 

First fix your waveform problem, then zoom in the time base on your scope to get more measurement precision. Also, probe the SAW signal at the EDIS module, as that is what really matters (who cares what it looks like at the MS if it looks like crap at the EDIS module).

 

Pete

[Matt Cramer]

Something's wrong with that ZIP file - it came up empty for me.

[SidWell]

Something's wrong with that ZIP file - it came up empty for me.

 

I just opened it. I right clicked on the file and selected 'open' it opened with Megatune 2.25.

 

I was also able to save it to a file, then unzip it, it also opened with Megatune 2.25.

 

I do appreicate your help.

 

Were you logged in?

[Noddle]

Something's wrong with that ZIP file - it came up empty for me.

 

I downloaded it last night, and it opened fine for me.

 

Nigel

[SidWell]

You probably have C30 and C12 installed (Dave and Ed caps).

Shucks The caps were never installed. That sounded like such a good solution too. I will remove the PIP input to MS, stick a 300 ohm resistor between the PIP and the ground on the EDIS unit and see if it generates a nice square wave all its own. The car won't start but I can at least see the timing pulse when it cranks. Back to basics, I guess.

[Matt Cramer]

Seems my Internet connection had hiccupped; the file's OK now. There is one setting that's off: You've set the cranking timing to "Trigger Rise" and it needs to be "calculated." Also check with a spark advance gauge in MegaTune to make sure the MS is commanding more ignition advance - it may not be.

[SidWell]

Also check with a spark advance gauge in MegaTune to make sure the MS is commanding more ignition advance - it may not be.

 

Thanks for finding the trigger error.

 

You could easily be right about the spark advance. I have read the section on the spark advance tool about 4 times and still not understood it.