Engine Runs, But no Advance. Bad Module?

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z-ya
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Engine Runs, But no Advance. Bad Module?

Post by z-ya »

My config:

V3 board, Megatune 2.25, 024s13 firmware

I've had my Datsun L6 runnning for a few days now, but I still can't get the advance to work. I can see the pulse width changing on the SAW output. Below is a scope shots of two SAW pulse widths superimposed on each other. One is 1 deg advance, the other is 25deg advance (sorry for the fuzz pic as my scope cannot print the screen to a disk):

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The image below shows some of the noise I am getting between each SAW pulse. I've tried everything to get rid of this noise. I have the PIP and SAW independently shielded with the sheilds only tied at the module. Unless the VIH of the module is under two volts, I dont' see this being a problem.

Image

The timing is rock solid at 10 deg, regardless of load or RPM.

Could I have a bad module? Do others have similar noiuse on their SAW output? BTW, the SAW output is super clean when on stimulator.

Pete
jsmcortina
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Post by jsmcortina »

Do yo have multi-spark turned on? I think that EDIS6 modules reject it and will revert to limp home mode.

How wide in microseconds are the pulses at 1deg and 25deg ?

James
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z-ya
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Post by z-ya »

It is in normal EDIS mode (not multispark).

About 1500uS at 1 deg, and 875 at 25deg. The pulsewidths are correct according to the EDIS FAQ page.

Pete
z-ya
Helpful MS/Extra'er
Posts: 35
Joined: Wed May 05, 2004 9:33 am

Post by z-ya »

OK, it looks like I found the problem. I'll know for sure tonight when I get a chance to fire it up.

I have the "Trigger Angle" in the "Spark Settings" set to 60 deg, rather than 0. Duh!! I kind of ASSumed that since the missing tooth is located 60BTDC, I should also set the trigger angle to 60 deg. NOT! From what I read, the trigger angle is controlled within the EDIS module, not by the firmware.

Another thing I discovered this weekend. Adding a 1uH choke in series with the SAW signal at the EDIS module removes the voltage spikes on the SAW signal. These spikes exceed 5V (closer to 10V), and could have an effect on the EDIS module. I verify the effect once I get the advance mechanism working. I will also post scope shots before and after.

Pete
z-ya
Helpful MS/Extra'er
Posts: 35
Joined: Wed May 05, 2004 9:33 am

Post by z-ya »

OK, got the advance working with EDIS. It ended up being both the module, and the fact that I had the trigger angle set to 60. It should be zero for EDIS. So I put a new module in (thanks to a lovely Ford Aeorstar), and uploaded the latest firmware. Have the idle timing set to 35 deg (idles a bit lumpy, but much better than with the advance at 10 deg). Yea, it's a mutt (Ford ignition, Dodge RAM throttle body, Chrysler Coils, Jeep air intake, Toyota brake calipers), but it sounds incredible. Can't wait to get it on the dyno. Maybe next weekend. Hear are some new photos:

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