G60 MS suddenly died

[ydrogs]

Preface - 80 Scirocco with a stage 3 G60 swap. Was running the stock Digi setup but switched over to MS. It's MS2 v3, running MSnS 3 with relay board and JAW WB controller. Still using the stock Ignition system (distributor, hall sender and coil).

I had it running great for about 2 weeks. Was driving it one day in 5th gear and the car just suddenly dies. No bangs, sputters or Pull over to the side of the road and open the hood and look it over. Nothing looked out of place so I try and start it. It turns over fine but won't start.

Tow it home and confirm there is no spark. Check all the connections on the relay board and all look fine. The computer light for the injectors light up when cranking and I have a noid light and it flashed while cranking at the injector. The wiring to the dizzy checks out as does the wire to the - side on the coil (continuity and signal).

After changing out the coil and distributor with different used components I can get an inconsistent very weak spark at the coil wire but not enough to start it. Both coils pass the Bentley tests. I have hooked up my megastim and all the reading on Tuner studios look correct when the dials are turned.

Any theories why my system would just quit? I am not very familiar with the MS board but familiar with all the car wiring. Is there some things to check that I am missing? Any help at this point would be appreciated, thanks.

[Prof315]

Does your MS tuning software show rpms while cranking? No rpms into MS = no spark and no fuel.

[oldschool eighty8]

Check your grounds, I learned the hard way where not to put them.

[need_a_VR6]

Check for spark at the plugs? Could be a dizzy/rotor/plug wire problem.

[sdezego]

What are you using for the Ign Driver (Ignitor)? The Scirocco IGN Module wired to MS or an internal IGBT?

If internal IGBT, make sure it did not get cooked (take cover off MS and inspect), which is my suspect. Especially, if it were the older VB921 IGBT.

[ydrogs]

Does your MS tuning software show rpms while cranking? No rpms into MS = no spark and no fuel.

Yes, it does show 200-250 rpms while cranking.

[ydrogs]

Check your grounds, I learned the hard way where not to put them.

Oh yeah, I have a Scirocco and know all about bad grounds and have a good amount of them. Where would you recommend not putting them?

[ydrogs]

What are you using for the Ign Driver (Ignitor)? The Scirocco IGN Module wired to MS or an internal IGBT?

If internal IGBT, make sure it did not get cooked (take cover off MS and inspect), which is my suspect. Especially, if it were the older VB921 IGBT.

Thanks for the tips! I know very little about the MS computer itself but I was able to so some searching of IGBT. I was able to locate where the IGN bridges were installed on the board to run the IGN and found the VB921. Upon opening the MS case there was that burnt electrical odor. The 3 fingers that go from the VB921 do look heated compared to the rest of the units on the heat sink but the connection to the board look ok and not burnt.
I will continue searching the web but is there a test for the VB921 to see if it is toast? I have a feeling it might be. Not sure if a photo will help but everyone like pictures



I just tested the voltage at the coil. I am getting 12V at both the + (battery) and - (S5 from relay board) side at key power. Is that correct?

Thanks for all the help so far. I am getting a lot further along with your ideas.

[Prof315]

Your VB921 IS toast. (good call shawn!) I'm not sure if the board is damaged from your picture.

[oldschool eighty8]

Oh yeah, I have a Scirocco and know all about bad grounds and have a good amount of them. Where would you recommend not putting them?

Keep them off the body, I ground my ms ecu by itself on the block.

[need_a_VR6]

Just looking at the color of the nylon nut it looks like the igbt overheated. I have a ton of Bips if you need one on the quick.

[DieGTi]

Underlying cause so it doesn't happen again? Better grounding of the board to the block? Less dwell?

[Prof315]

Underlying cause so it doesn't happen again? Better grounding of the board to the block? Less dwell?

VB921 is the underlying cause. BIP373s are MUCH more robust and have built in overheat/over current protection.

[sdezego]

ahh, yes. It is cooked. I had the same thing happen to me when I first built mine for my G60 some years back. I got only about 12 miles though and mine was a bit more meltier LOL... Luckily, I was able to replug in Digi to make it back home.

I never really found out why it happened (either the coil/dwell settings I was using, Nylon bolt loosening to heat sink or just a finicky VB921 IGBT).

At the time, there was no BIP IGBT option recognized, so I replaced it with another VB921 and changed my coil/dwell settings. Been running like that for years now, however, I would absolutely replace with the more reliable BIP IGBT.

As Jeff stated above, check that tracer on the board. That last leg looks like it definitely transferred some heat to the board. I also got rid of that Nylon bolt afterward and used a real bolt/nut to attach the IGBT to the heat sink (I don't recall if it needed to be isolated or not).

Definitely check your coil and dwell settings after you replace.

[sdezego]

Pic so you don't feel alone




Replaced with Screw and Brass standoff from old computer case hardware (ignore the TIP120 added to the left for IAC)

[need_a_VR6]

I have used nylon on all my builds without issue, but I do use just a tiny hit of superglue to lock the threads. The BIP373 needs to be isolated with mica and the nylon hardware is some extra insurance.

[ydrogs]

Keep them off the body, I ground my ms ecu by itself on the block.

I currently have a ground flower attached to the firewall in the passenger foot well where all the MS components are. I will take the MS ground off the flower (shared by small amp, relay board and wideband controller) and run it through the fire wall to the block.

Can I ask what the difference between the 2 grounding locations is though? Wouldn't the negative post on the battery be the best place to ground?

[ydrogs]

Definitely check your coil and dwell settings after you replace.

This is what I think I should have done on install. I bought the system out of a running car and I do not think we checked the coil settings when it got installed. I do think we were both using the same Bosch coils but without checking the serial numbers I can not be certain. A lot of coils look the same but do have different properties.

[oldschool eighty8]

Grounding to the block is the best option for anything ecu related. The problem with grounding to the body where other things are grounded like the radio and interior lights ect. is it's not a clean ground sigal. It shoud be in a location by itself.

[ydrogs]

Just looking at the color of the nylon nut it looks like the igbt overheated. I have a ton of Bips if you need one on the quick.

The quicker the better but since I did not assemble this or any other computer board I am not sure I want to risk doing this. I have soldered a lot of wires together but never on a circuit board.

Any comments on this company and their service?
http://www.symtechlabs.com/catalog/m...vice-p-44.html
$30 seems acceptable to me but do not know anything about them.

I do have a soldering iron and a gun so maybe I should just sack up and do it myself.
How much would you charge for a BIP?

[need_a_VR6]

I will do it for $20 plus shipping.

[ydrogs]

Your VB921 IS toast. (good call shawn!) I'm not sure if the board is damaged from your picture.

Do these help?





It looks ok except for that last pin where it bubbled up. I think I can still see the board wire intact though.

[ydrogs]

Grounding to the block is the best option for anything ecu related. The problem with grounding to the body where other things are grounded like the radio and interior lights ect. is it's not a clean ground sigal. It shoud be in a location by itself.

Never knew that about ECU grounds. Thanks for that nugget of info

[sdezego]

Yea, the board looks fine. That goop looks like it either oozed out of the IGBT or is from the nylon bolt, etc.

Send it to Paul ^ need_a_VR6 He will square it up for you and likely give it a once over to make sure there is nothing out of place.

In that last pic, I noticed they used a Resistor on the IGN. You can see where I used a straight piece of wire to jump. iirc, the resistor is only used to scope the IGN signal. Not sure if could have caused anything adverse here. My guess is just a crap VB921.

I am running the stock G60 coil and have been running for over 5 years now since I initially smoked my VB:

In MS1 my settings were

6.0 Crank
2.5 Running
0.1 Min Discharge

(Inverted Spark of COURSE)

In MS3:

Cranking Dwell: 6ms
Max Dwell Duration: 2.6ms
Max Spark Duration: 1ms
Spark output: Going High (Inverted)

Some settings may be different in MSII

[ydrogs]

Send it to Paul ^ need_a_VR6 He will square it up for you and likely give it a once over to make sure there is nothing out of place.

Going in the mail tomorrow

[ydrogs]

Got the ECU back back from Paul and it started right up after installing it back in my Scirocco. Thanks goes out to all who helped me work out this problem on here and especially to Paul who replaced the fried transistor.

[need_a_VR6]

Glad it's back up and running

[ValveCoverGasket]

VB921 is the underlying cause. BIP373s are MUCH more robust and have built in overheat/over current protection.

yeah this...

vbs dont like to take a lot of dwell... the bosch stuff is much nicer.

[-RalleyTuned-]

Got the ECU back back from Paul and it started right up after installing it back in my Scirocco. Thanks goes out to all who helped me work out this problem on here and especially to Paul who replaced the fried transistor.

Was this car ever up in WA? That looks shockingly similar to the car my roomate had YEARS ago.