I finely got everything installed and running yesterday. Hooray.
Unfortunatley i had a few problems.
1. on tick over the timing was spot on, but about every three to four second the timing would blip slightly for a brief moment then return to normal.
2. Tacho drive from the MJLT worked straight away with my tacho, but when revving over 3000 rpm and lifting off the needle would return to 0 for a couple of seconds then fly back up to the correct reading.
Today i went for a proper shake down, using maximum revs etc,
After holding high revs in top (about 5000 rpm) for a couple of miles i lost all ignition completely, fortunately i managed to roll to a parking area to have a look..
All the fuses were intact so as i had the original set up still in tyhe car i connected the coil back up and restarted the car it ran for a few moments then stopped again. Then i Noticed that there was smoke coming from the MJLT........Whoops!
I quickly deduced that it was the tacho drive still connected to the now reinstated coil and disconnected it and sure enough I got spark and could carry on now running on the distributer.
I have just removed the MJLT and have found T2 completely burned out, I haven't been able to test the EDIS or MJLT yet to see if there is any real damage, but does anyone have any theories why everything just stopped.
Could it be the Tacho was drawing too much current?
Could it have anything to do with the unstable tick over advance?
All theories welcome.
Andy
Whoops
Moderators: JeffC, rdoherty, stieg, brentp
Hi Andy,
Your first problem seems to be around something failing with the EDIS or it's installation. Remember; the EDIS runs by itself in 'limp-home' mode, so a MJLJ failure would not cause the whole system to stop.
The second problem, where T2 was destroyed - it seems that the MJLJ TACH_OUT was still connected to the tachometer when the original coil was re-enabled. The high voltage pulse from the (-) terminal of the original coil likely cause the damage.
The unstable advance might've been caused by noise on the PIP/SAW lines going between the MJLJ and EDIS module. This is usually not a problem with good shielded wire and with the shield properly grounded. Another source of EDIS/ignition advance instability is a vibrating sensor bracket. This problem ususally manifests itself in the mid RPM range.
Your recommended course of action:
1. Diagnose the EDIS installation- leave the MJLJ *disconnected* and see if you can get the engine running on EDIS alone.
2. Evaluate the condition of the MJLJ:
* Clip off T2- you will not have TACH_OUT but you can deal with that later.
* Power it up on the bench, or in the car without the engine running. Verify the unit is alive by using the configuration software.
* If the unit seems alive, hook it up to the EDIS installation, start the engine and see if it still controls ignition advance.
* If you got this far, you can replace T2 with a new 2n2222 transistor. Check for other damaged components as well.
* Re-enable your TACH_OUT. If you still see the unstable tachometer reading, you can try one of the other tachometer driving schemes in our installation guide.
Your first problem seems to be around something failing with the EDIS or it's installation. Remember; the EDIS runs by itself in 'limp-home' mode, so a MJLJ failure would not cause the whole system to stop.
The second problem, where T2 was destroyed - it seems that the MJLJ TACH_OUT was still connected to the tachometer when the original coil was re-enabled. The high voltage pulse from the (-) terminal of the original coil likely cause the damage.
The unstable advance might've been caused by noise on the PIP/SAW lines going between the MJLJ and EDIS module. This is usually not a problem with good shielded wire and with the shield properly grounded. Another source of EDIS/ignition advance instability is a vibrating sensor bracket. This problem ususally manifests itself in the mid RPM range.
Your recommended course of action:
1. Diagnose the EDIS installation- leave the MJLJ *disconnected* and see if you can get the engine running on EDIS alone.
2. Evaluate the condition of the MJLJ:
* Clip off T2- you will not have TACH_OUT but you can deal with that later.
* Power it up on the bench, or in the car without the engine running. Verify the unit is alive by using the configuration software.
* If the unit seems alive, hook it up to the EDIS installation, start the engine and see if it still controls ignition advance.
* If you got this far, you can replace T2 with a new 2n2222 transistor. Check for other damaged components as well.
* Re-enable your TACH_OUT. If you still see the unstable tachometer reading, you can try one of the other tachometer driving schemes in our installation guide.
Thanks Brent
Managed to get some time today and do some tests. connected EDIS back up and car ran AOK.
Connected MJ back up with out engine running and tested and all looked ok, so I held my breath and started the car, Low and behold every thing worked fine (with the exception of the Tacho, obviously)
I have checked and double checked all connections and the Screening on the VRS lead, all fine also the screen cable between the EDIS and the MJ all ok.
The bracket is rock solid and there is no vibration at the VRS.
The timing is more stable, but about every 30 seconds there is a very slight blip.
I think i am probably being a bit too critical.
I will try the Fly back method for the Tacho as this is how the original setup is wired (smiths).
Are there any components that may shut down if over heated? I can't find any reason why everything should have shut down.
Does the coil pack draw more current than a normal coil?
I guess i will just have to go for another spirited drive to find out!!
Thanks for the Moral support I am very impressed with the robustness of the MJ This is the second time i have tried to kill it and failed. (haven't checked all the output though!!)
Andy
Managed to get some time today and do some tests. connected EDIS back up and car ran AOK.
Connected MJ back up with out engine running and tested and all looked ok, so I held my breath and started the car, Low and behold every thing worked fine (with the exception of the Tacho, obviously)
I have checked and double checked all connections and the Screening on the VRS lead, all fine also the screen cable between the EDIS and the MJ all ok.
The bracket is rock solid and there is no vibration at the VRS.
The timing is more stable, but about every 30 seconds there is a very slight blip.
I think i am probably being a bit too critical.
I will try the Fly back method for the Tacho as this is how the original setup is wired (smiths).
Are there any components that may shut down if over heated? I can't find any reason why everything should have shut down.
Does the coil pack draw more current than a normal coil?
I guess i will just have to go for another spirited drive to find out!!
Thanks for the Moral support I am very impressed with the robustness of the MJ This is the second time i have tried to kill it and failed. (haven't checked all the output though!!)
Andy
Hi Andy,
Glad the MJLJ survived that mishap!
I think with the smiths tach you will find the diode circuit a better solution. Regarding the timing blip: run the configuration software and see if the timing "blip" coincides with a change in reported advance. At idle your timing might be on the edge between bouncing between one degree value or another. In any case, is it a big blip or a small one? The timing should be rock stable, always, at a given advance.
Glad the MJLJ survived that mishap!
I think with the smiths tach you will find the diode circuit a better solution. Regarding the timing blip: run the configuration software and see if the timing "blip" coincides with a change in reported advance. At idle your timing might be on the edge between bouncing between one degree value or another. In any case, is it a big blip or a small one? The timing should be rock stable, always, at a given advance.