H.F.B.

Actually only one of the drivers was dead. I don't remember which one was it. But I changed both, as you can see on the picture both didn't look very well. I sourced them on ebay. Look for ISL9V3040P3 --> https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=ISL9V 3040P3&_sacat=0
I think the problem is that the transistors have to trigger the entire supply voltage for the primary coil without heat sink. If we used the VAG Coil 032905106b with integrated ignitor, then we shouldn't have this problem. Notice the heatsink of this coil for the ignitor. COP with built-in ignitor would IMHO be the best solution, but I don't know a suitable part for the 8V engine.

V2Rocket

would love to know how to set up that coil to run off the VEMS.

my original-from-1984 plug wires might be getting tired...
so maybe i'll throw WS at it while im in there LOL

H.F.B.

like this for a coil with built in ignitors.

V2Rocket

i meant id need to figure out how to change the config of VEMS (probably add wiring) to drive the two "ignition pairs"

odonnell

You should be able to just use one of the spare outputs and configure it as a second spark output. May even have dedicated spark outputs that aren't in use. Then just configure this pin in the tuning software to be your 2nd ignition channel and set it up as wasted spark. The major point here would be that the above coil is logic-level, meaning it has built in igniters/amplifiers. Therefore you don't need to add one of those transistors to your ECU circuitry, all it needs is a low-current signal to tell the coil to fire. The actual high-current pulse to the plugs is powered by the heavy wiring to the coil unit itself. So, setup should be easy. That's how I did my LS1 coils with Megasquirt... it was less work than actually using the stock coil.

However bear in mind that your original (single) coil output will have that transistor as part of the circuitry and you shouldn't have 1 channel using that (the coil has that already) and 1 channel as logic level. Maybe you can find 2 spare pins or unused spark outputs and configure them as your 2 channels, leaving the original spark circuit intact. That allows you to change back and forth easily if you need to at the expense of running 2 new wires instead of 1.

Also make sure to find out the appropriate dwell time for any coil you hook up. Generally it's between 1-5ms and you can find it online by searching. It's probably a lower dwell time than the stock coil and not updating that value can cause overheating or failure.

shortyboy

I was able to source a ignition driver transistor from a local Rennlister who also has VEMS on his supercharged 944. He also blew his transistor. Luckily he had alot of spares. I also ended up burning the trace from pin 36 to emitter pin on transistor. So i placed a jumper wire from pin 36 to new emitter pin. Shes running like before. Still trying to figure out idle/stumbling issue. I adjusted after start prime from 6ms to 8ms, but not change. still need to turn ignition to on position 3 times, then start on the 4th to get a good start. Might add more fuel and see how it goes. I also figured out TPS wiring. Factory turbo TPS connector - White/Red is 5V - Brown is Ground - White/Green is Signal. I installed a 65mm Ford throttle body with TPS, which took alot more effort than I thought it would LOL. Will update throttle body thread with pics and wiring. Was hoping new TPS would fix idle issue, it didnt. I dont think its the speed/reference sensors, since I only need to turn key ignition on position 3x. I also attached a log file from today after new transistor was installed. This was with a good start. Will update with bad start.

Raceboy

Blowing IGBT happens when firmware is flashed and ignition/injector fues is not pulled or config change is made (in Wayne's case I suspect he changed to inverted coil output => instakill for transistor).

The VAG coilpack above can be fired from stepper output (EC18 pins 4, 5, 10, 11), just needs 12s supply and additional ground connection to cylinder head.

Raceboy

Regarding your starting, you need to add some fuel for afterstart table or try to add a tad cranking fuel (go to Starting/Idle menu and add 10% to cranking VE and give it a try).

shortyboy

Yep was trying to fix stumbling issues. BTW, do the VAG coil packs on the VEMS store fit the 8V head? Been looking to do coil on plug to clean up the engine bay a bit. Going to try a wire tuck and hide majority of wires. ( yes, its the current JDM fad, figure I try it for us transaxle crowd )

Yes, been slowly adding fuel on afterstart and pre-crank. But shouldnt the stumbling issues go away after reaching operating temp? Much Appreciated Peep. I figure I bother you enough via Email and try the VEMS community on here.

V2Rocket

shortyboy - was the Ford TPS as easy as connecting the relevant wires to eachother on the OEM harness, and then re-calibrating in VEMStune or anything else needed?

Raceboy - can a "plug-and-play" single-coil VEMS be somehow upgraded to do WS? another plug-in adapter (something easily reversible if needed)?

Raceboy

No adaptation needed, just route two wires from EC18 pins 4 and 10 for example to coilpack input pins and give coilpack 12v and ground.


Wayne, I refer as coilpack to the wasted spark coilpack, you are referring to coil-on-plug (COP) coils and no, these do not sit well on 8v head. Only one that would is the shortest one from 2.3 v5 engine for example but still not good.

Regarding blowing IGBT's, I have always said that if engine runs well at full throttle and load, there's nothing wrong with ignition system and the issue lies elsewhere. It almost never is an issue, 1% of cases is where plugs are old or something like that.

shortyboy

Yep, I just spliced in proper wires from ford tps to wires on OEM harness and calibrated in VEMStune. Thats it.

Understood. Never touching that settings again. Lol. Looks like I need to get longer spark plug wires to hide wasted spark coil near battery tray then.

V2Rocket

cool.
i noticed in the ignition settings under base setup there is an option for "EDIS"...is that the correct software-side change or is there more to it past that?
i tried googling this and got lots of vems.hu results but its all written in computer-people-speak

Raceboy

EDIS is something to ignore, it is ONLY used when real EDIS module is used what decodes wheel and feeds VEMS with simple square signal.

There's nothing else to change other than change output channels to stepper ones.

V2Rocket

cool...love VEMS.

found this..
http://www.vemssupport.com/forum/index.php?topic=441.0

where rob says:
Configure Ingition Outputs
Ensure that the Stepper Motor Driver is enabled as above. Then configure the outputs, using the Four Cylinder example as above the
Go to Settings->Ignition Outputs and set the sequence:

for a 1342 4-cyl i assume that would mean inputting as: EC18-4, EC18-10, EC18-4, EC18-10 ?

one guy there (and odonnell, above) mentioned tweaking dwell time - necessary?