VW coil or ignitor keeps dying (FIXED)

jassem99 · Post by **jassem99** » Sat Feb 25, 2006 2:43 pm

Hello all,

** Moderator EDIT: See last post. **

I'm using a VW 3 pin coil (same as ABA or VR6 dizzy coil), with integrated dumb ignitor. Last week I damaged the first coil after a seemingly harmless mix-up in wiring a V3 (I used VB921 to trigger OEM module instead of bypassing VB921). Now I've reverted to using a V2.2, and i'm not using VB921. Car ran fine this morning but died this evening when i left ignition switch on for just under a minute. Coil#2 is dead. Am i missing something here?

Using 029g, and 'spark output inverted'. Crank dwell 5ms, running 3ms and minimum 0.5ms.

I could wire up the coil from the fuel pump relay, but that would defy the purpose of having a plug and play harness using all OEM wiring. Thanks.

Basil

captain16vgti · Post by **captain16vgti** » Sat Feb 25, 2006 3:31 pm

I made this write up and posted it on the vwvortex. Hope it helps.

Alright guys, I just got my 16v fired up using my v3 board to control spark. Im gonna try to make this a very detailed write up covering the whole process. Before I go on any further id like to say thanks to Dave (cdndub) and Calvin (kalvinlk) for all the help. This write up is based off of Dave's original write up but it will include a couple of things that were left out along with pictures. Thanks again guys.

First off, I purchased my v3 board already assembled because I didn't have the time to build it myself. Because of this I was kinda left out on the basic internals of ms. I read and asked a bunch of questions and eventually understood everything (well mostly everything

).

This pictures is good to use to get a basic idea of where things are located on the v3 board.

With all that said I will now get on to the procedures that need to be made to make this thing control spark.

First things first. TACHSELECT should be jumperd to OPTOIN. If its not please do so.

2. After that you will need to solder a jumper wire to the previous jumper and run it over to the +5 pad above the proto area. You can see the +5 pad on the top side of the pcb. Like Dave said, This will give you 5v to power the hall. (cleaner signal)

3. Next you will have to cut the jumper between XG1 and XG2 if there is already one installed. After that you will need to run a jumper wire from XG1 and IAC-1A. This is the input for the tach signal from the dizzy.

4. If not already done you will have to jumper TSEL to OPTOOUT.

5. This step pretty much depends on which firmware you are running on your v3 board. Basically this step is where you send a signal to the IGBT (onboard ignition driver) to let it know when to fire. On the v3 board the input is labeled IGBTIN. The output to this is what varies depending on what code you are using. The default output for the standard ms2 code is JS10 (ign). If you are using the standard ms2 code then run a jumper from IGBTIN to JS10.

I on the other hand am still using the ms1 processor but running it with MSnS -E so I can control spark. If your running MSnS like I am then the default output is one of the led's. In this case you will have to run a jumper from IGBTIN to the top of R26 with a 330ohm 1/4 watt resister inline. You will be able to see R26 from the top of the pcb board. You can also refer to the pcb picture posted above. The reason you don't want to use JS10 with MSnS is because JS10 is a input for knock control. Check out the pictures below.

6. Next jumper IGBTOUT to IGN if not already jumperd. This is the output to the coil (pulsed ground).

Now that all the internal mods have been performed we will move onto the wiring. Your basic hall sensor will have three wires. The three wires consist of a ground, power and signal. In almost all cases the middle wire is the signal wire. This wire will be ran to pin 25 or pin S1 on the relay board.

Next is the ground wire. This wire will most likely be brown/white or just brown. You want to find a good grounding point for this wire. The last of the hall wires is the power wire. This wire should be red/black. The power wire will be ran to pin 24 or the TACH pin on the relay board. Finally its time for the coil wire.

All you need to do is run a wire from pin 36 or S5 (relay board) to the negative side of the coil. This wire is a pulsed ground and will tell your coil when to fire. That's pretty much it guys. You've just moded your v3 board to control spark. If anyone wants to add to this or ask any questions please feel free.

-Chris

jassem99 · Post by **jassem99** » Sun Feb 26, 2006 3:37 pm

captain16v,

Thanks for the post. I removed the VW ignition module (which is integrated with the coil) today. Instead, I wired a VB921 in the V2.2 using JP1/7 as ground. When the ignition switch is on (engine not running), the VB921 becomes so hot that it starts making crackling noises, and the plate it's attached to becomes very hot to the touch. I switched off ignition before anything melted though! Why is the VB921 overheating? Is JP1/7 not a good enough ground? Or is there more to it than a good ground? I'm using 'spark output inverted' as per instructions.

Interestingly, when i swap the v2.2 for the v3 i have, the VB921 on the V3 stays cool in the same situation (switch on without engine running).

I'm confused? Surely the coil doesn't have to be powered from the fuel pump relay if i'm not to melt VB921? And why does the v3 behave while the v2.2 wants to melt its VB921 (and has already destroyed my VW module). Thanks.

Basil

Post by **jsmcortina** » Mon Feb 27, 2006 3:31 pm

Are you running the same code version with same settings on v2.2 and v3 ? They ought to behave identically if the wiring is ok.

Please do wire the coil via the fuel pump relay - it is a second failsafe to make sure the coil cannot get damaged in this kind of situation.

JP1/7 is not a good enough ground in my opinion, wire directly so some of the earths on the DB37.

James

captain16vgti · Post by **captain16vgti** » Thu Mar 02, 2006 2:16 am

Basil,

Im not to familiar with the 2.2 board to be honest. My first board was a 2.2 but I never had it controlling my spark. I believe I had the same situation as you are having but with my v3 board. My onboard ignition driver was also getting very very hot just after a few seconds of the car being on. It turns out I was using the wrong spark output. I was using JS10 at first which is the default for MS2 code. I soon realized that I needed to use one of the leds for a output. I did that and it started right up. Hope this helps.

-Chris

jassem99 · Post by **jassem99** » Thu Mar 02, 2006 12:54 pm

captain16vgti wrote:Basil,

Im not to familiar with the 2.2 board to be honest. My first board was a 2.2 but I never had it controlling my spark. I believe I had the same situation as you are having but with my v3 board. My onboard ignition driver was also getting very very hot just after a few seconds of the car being on. It turns out I was using the wrong spark output. I was using JS10 at first which is the default for MS2 code. I soon realized that I needed to use one of the leds for a output. I did that and it started right up. Hope this helps.

-Chris

I seem to have done a similar mistake. My v2.2 was previously running an EDIS equipped Ford, and hence the mods made were "Solder 1k resistor between the (-)leg of D17 and the right hand end of R23 (+5v). Run a length of wire from the (-) leg over to SAW on EDIS module". When i switched to VB921, i simply ran this SAW wire to the VB921 and caused it to overheat.

What I should have done for the VB921 mod is: "a wire from RHS of R25 to the VB921 via a 330ohm resistor". I did that now and the VB921 runs cool.

Basil

qbngolf · Post by **qbngolf** » Tue Mar 07, 2006 7:48 pm

so i have my v3 board wired up like this and when i turn the ignition key to on vb921 turns hot real quick, i have a 3 wire ignition module it is on an obd2 2.0 aba 8v. first i tried wiring the trigger wire to the middle wire on the coil harness, my problem was getting the car to stay running at idle. it did idle nicely but then out of nowhere it would die. so then what i did was i cut the ignition module off of the coil and i wired one terminal to the fuel pump positive and the other terminal to the megasquirt and then i turned on the ignition and vb921 got really hot. i dont understand whats going on. any help would be greatly appreciated

Peter Florance · Post by **Peter Florance** » Tue Mar 07, 2006 8:26 pm

qbngolf wrote:so i have my v3 board wired up like this and when i turn the ignition key to on vb921 turns hot real quick, i have a 3 wire ignition module it is on an obd2 2.0 aba 8v. first i tried wiring the trigger wire to the middle wire on the coil harness, my problem was getting the car to stay running at idle. it did idle nicely but then out of nowhere it would die. so then what i did was i cut the ignition module off of the coil and i wired one terminal to the fuel pump positive and the other terminal to the megasquirt and then i turned on the ignition and vb921 got really hot. i dont understand whats going on. any help would be greatly appreciated

Try spark output inverted = Yes
(instead of what picture picture shows as "no")

qbngolf · Post by **qbngolf** » Fri Mar 10, 2006 6:26 am

alright well ill give it a shot tonight and let you know how it goes

qbngolf · Post by **qbngolf** » Sat Mar 11, 2006 4:19 pm

got it running now the problem is when the motor gets cold i try and start it, it starts, and then dies unless i keep my foot on the gas for like five seconds. my other problem is i have kind of an idea on how to tune spark but i am by no means a genius at it. any pointers would be greatly appreciated

GodSquadMandrake · Post by **GodSquadMandrake** » Sat May 13, 2006 3:15 pm

I just melted my VB921 too

. I am guessing this is because my spark output was not inverted. These directions need to be made more clear. It's too easy to make mistakes.

Where do you buy another VB921?