I need some MegaJolt help.....

[manx3094]

I just got my dunebuggy running on my EDIS and MegaJolt ignition. The motor is a 1641cc with a Weber 40DCNF carb. The software shows about 12 degrees advance at 1000 rpm and it does not idle smooth. When i put the timing light on it I'm seeing about 20 degrees advance. The motor smooths out as the rpms increase and yes i can see both the software and the timing marks advance, however, they never seem to match.
Do i need more advance at idle? and why doesn't the software and timing light match?

[xellex]

is your trigger wheel missing tooth correctly alligned with the sensor?

[manx3094]

I just checked again and if it's off it's not more than 1 degree or so. I've enclosed a couple of pics to show my set up.

[miniman82]

Ummm...

Maybe I'm not seeing this right, but that looks like a 34+1 trigger wheel, not 36-1. It's not supposed to have a single fat tooth, is supposed to be 36 teeth, one of which has been removed. Hence, 36 minus 1.

[Dale M.]

Ummm...

Maybe I'm not seeing this right, but that looks like a 34+1 trigger wheel, not 36-1. It's not supposed to have a single fat tooth, is supposed to be 36 teeth, one of which has been removed. Hence, 36 minus 1.

Looked at it and counted 35 teeth and 1 hole..... But I have old eyes.... You might be counting gaps mistaken them for teeth...

IF I am seeing this correctly you sensor is at about 4 o'clock position?..... Other wise "gap" in toothed wheel wheel looks to be in wrong place....

Traditionally the sensor for VW is at about 1 o'clock seems kind of odd to have it at 4 o'clock position....

I having a little trouble with missing tooth and relationship to pulley keyway seems to be about 3 teeth (30°)off



This is how MS handles EDIS which can not be much difference than MJ....



But as long as you have engine at TDC and sensor is 9 teeth (90°) ahead of missing tooth (TDC) there should not be any issue...

Dale

[miniman82]

Yep, my eyes were playing tricks again. I was seeing silver teeth, but now I clearly see the trigger disc bolted to the pulley. It was a long day today...

[xellex]

I can't be sure from these pictures, but your sensor seems to be 20 degrees to the right of ( or after) bottom dead center.
In that case, with the pulley bolted on, and set at TDC, you should mount the sensor (which I can't see in the pics) at 70 degrees to the right of top dead center (or before TDC). So if I'm correct, your sensor bracket is aproximately where it should be. You just need to align it right.
Dale, I think you got it wrong! The sensor should not be ahead of the missing tooth with EDIS-4. Actually the missing tooth is 90 degrees ahead of the sensor.
That picture you posted is viewed from behind, and it can be misleading.
This is what it should look like, while looking at the pulley of your type 1 engine:

[Dale M.]

Dale, I think you got it wrong! The sensor should not be ahead of the missing tooth with EDIS-4. Actually the missing tooth is 90 degrees ahead of the sensor.
That picture you posted is viewed from behind, and it can be misleading.

You may be right... Its not my pic though its manx3094's pic...

Here is pic manipulated some....



Where am I going wrong.... Red square in pic is pulley key way ( should be at 9 o'clock when crank is at TDC..... By my fuzzy brain I see it off by 1 tooth (10°)... I guess my question is missing tooth 90° to TDC (or offset appropriate number of degrees in relationship with crank TDC and degree offset of sensor......





Other scenario may be the sensor is 10° off case center line so then missing tooth may at 100° and be legitimate....



IF sensor is 100° off case split line (clockwise with crank TDC) then everything may be ok if missing tooth is at 190° mark on pulley....


Dale

[xellex]

We definately need better pictures, or more info here, but by looking at the pic you modified, and applying it to the face of the pulley, the missing tooth is exactly at 10 degrees off BDC. Taking this into account, this is where the sensor should stay.

Work%20Camera%20162%20(640x482)%20(300x226).jpg

Now, looking at the other picture, with the sensor bracket, I think the one you circled is a retaining bolt. The one higher should be the sensor, but eaven in that case, I think it sits higher than it should be. Doing the math, it's probably 8 degrees higher (at the 72 pulley mark instead of 80). I'm saying that by substracting 12 degrees (seen in mjlj software) from the 20 degrees seen on the timing light.

Work%20Camera%20167%20(300x226).jpg

That would be the reasonable explanation, and in that case, you should lower the sensor to an angle of 10 degrees to the horrizontal (or to the 80 degree pulley mark).

The only other thing I can think of, is maybe you have some trigger wheel offset programmed into MJLJ. You should check that too.

[manx3094]

Thanks for all your help and discussion. With #1 at TDC the sensor (top one in the pic, bottom is a bracket retaining bolt) is mounted at 72 degrees to the right of TDC on the pulley. I counted 90 degrees further around to the right on the front of the pulley and placed the missing tooth at would be 22 degrees.

A further update: after the motor was running for a little while I felt my exhaust pipes and it seems as though #1 is not firing. I pulled the plug and it is indeed firing so the problem must be fuel related somehow. The plug was dry and cold. When I 1st tried to start it on the EDIS/MegaJolt the motor backfired thru the exhaust real hard. I'm thinking I may have bent a valve. I will run compression test tomorrow. I pulled the valve cover today and the push rod and rockers seem to be OK.

Again, this is a single carb setup and cylinder #2 is firing so I don't think it is a carb issue.

[Dale M.]

Maybe a weak coil?.... Will fire with plug out of cylinder but not in cylinder under load?

Remember you actually have 4 ignition coils with EDIS you are just firing them in pairs....

Dale

[miniman82]

Remember you actually have 4 ignition coils with EDIS you are just firing them in pairs....

No, there's only 2 coils. The secondary of each runs from plug to plug.

[Dale M.]

Like dis.... Only dis be 6 cylinder coil pack...



Dale

[miniman82]

Kind of a poor picture, but yeah like that. Or dis. That and this an uh...



Whatever.

[Dale M.]

Hey.... When you are pirating images off internet you can't always be to choosey...

How bout dis 4 1/2 of coil module ( 2 of 4 cyl)...



Dale