EDIS timing confusion

vinister · Post by **vinister** » Sun Sep 10, 2006 11:17 am

I've had my car running great on EDIS for about a year. I've just installed the cam and now I have to make big adjustments to my map for it to run correctly. It's very difficult to tune for a good idle. I just have a few questions.

1. Is my cam timing and EDIS wheel position correct? There is a notch on the crank pulley, and a notch on the block. The engine is at TDC and the cam notch is lined up with the notch on the valvecover. The missing tooth on my 36-1 wheel also happens to line up with the TDC mark, which is exactly 90 degrees ahead of where the VR sensor is mounted, at the back of the motor. Everything seems to be lined up perfectly. However, the advance reported in megatune is different from the actual timing by about 15 degrees. What would cause this? I always just used the figure I got with the timing light, and ajusted accordingly on my ignition map. It's just making it confusing to tune and I'd like to fix it.

2. I find the gauge and wording used here and in megatune quite confusing. When you say -10* BTDC, is that actually 10 degrees after top dead center because of the - (neg) sign? Since the term 'advance' means earlier, before top dead center, when its represented with the - (neg), is that retard? Can someone clear this up for me?

3. When viewing with a timing light, my timing occasionally jumps around a little bit. Just within about 5 degrees. Its quick, probably only one spark, maybe 2. just looks like a little vibration. Is that normal?

4. I just installed the cam yesterday and I seem to have lost a lot of power. Its just a mild cam, and it is suitable for a stock OEM fuel system. However it really played havoc with my MS map, making the idle very challenging. It's rich all over the driving range now (havent had time to tune yet), and seems to be 'pushing back'. It's noticeably slower than it was before, although somewhat more linear. Is this common for a simple mild cam install? I didn't realize I'd have to completely retune my map.

Thanks!

vinister · Post by **vinister** » Mon Sep 11, 2006 7:56 am

bump... anybody??

jsmcortina · Post by **jsmcortina** » Mon Sep 11, 2006 8:18 am

Disconnect the SAW wire from Megasquirt to the EDIS module and strobe the timing. It must be 10 BTDC. If it isn't then you need to move your VR sensor or wheel until it is. Make sure that your strobe is compatible with wasted spark systems.

Once you have done this, reconnect the SAW wire and confirm that the actual timing matches the reported timing in Megatune.

Are you running MS1/Extra or MS2 ?
Make sure you follow the relevant install instructions for settings parameter right for EDIS.

James

vinister · Post by **vinister** » Mon Sep 11, 2006 8:28 am

thanks!

Ok, with the SAW line disconnected, I get 15 degrees BTDC. Unfortunately, I must have messed up as to the exact positioning of the missing tooth. Moving the wheel isn't really an option since clearance is so tight, I'd have to drop the motor to remove the pulley. I'll have to look into moving my VR sensor abit. Is there a way I can adjust for the 5 degree difference in megasquirt, and then everything would line up?

What doesn't make any sense, however, is that even with a protractor, the missing tooth is exactly 90 degrees ahead of the VR sensor. No matter how many times I check it, it really looks 100% correct. Could there be some other issue causing the delay?

As for the light being Wasted Spark compatible, I looked in the manual and it didn't say anything about it. It's just a basic light with an ajustable 'advance' wheel on it. It does seem to correctly report the changes I make.

i am running MS1/extra with the latest code.

One more question: My engine idles BEST when my timing light is reporting 35 degrees of advance. It's a 2.0L 8V vw motor, with a mild cam. Is that normal?

thanks so much!

jsmcortina · Post by **jsmcortina** » Mon Sep 11, 2006 8:30 am

Sounds like a lot of advance. The adjustable lights are usually NOT compatible with wasted spark. Use it on the zero setting only and mark the pulley.

I'm afraid there isn't an easy way to adjust for the 5deg error, you need to adjust the VR.

James

vinister · Post by **vinister** » Mon Sep 11, 2006 8:24 pm

James thanks alot for your help!

I think you're right, my timing light seems to act a little goofy when I turn the dial. I'm going to just get a better one and then we'll see whats really going on.

Thanks!!