# Megasquirt: coil outputs a constant 12v to dizzy



## ijcameron (May 17, 2001)

This is MS1-Extra, on an ABA with a dizzy and coil. I followed the "next cylinder" set up in the MS manual, made the necessary changes in "Spark Settings"to get the spark and dizzy angle correct. 

Fuel is working, the engine is cranking, but no spark - the coil wire to the dizzy reads a constant 12v with the key in the "on" position, down to 9V in the "crank' position.

This doesn't sound normal, does it 

Do I have a setting wrong in Tunerstudio (eg. Spark output A is permanently grounded), or is it something else?


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## Prof315 (Jan 5, 2009)

Are you using the stock Dizzy or has it been modified to a 4 window set up?


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## ijcameron (May 17, 2001)

The dizzy has been modified to have the 4 window wheel.


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## need_a_VR6 (May 19, 1999)

You shouldn't need to run next cyl mode with a VW distro. 

Do you see rpm in the tuning software? Does it seem reasonable?

What hardware setup and mods do you have? Which coil ABA or older round?


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## ijcameron (May 17, 2001)

Thanks for the replies.

Codebase is the most recent MS1-Extra (y4?). I'm using TunerStudio 0.999h. Here's the MSQ file, if it helps: http://www.gigasize.com/get.php?d=h0q8cmx9t3b 

RPM in TS when cranking is a steady 280 - 300RPM, which seems right.

Coil is from a Digifant II, i'm not using the 7 pin dwell module- dwell is MS controlled: http://forums.vwvortex.com/showthread.php?5195234-Megasquirt-and-Digifant-TCI-ignition-coil

Board mods: 1. For Hall sensor: TSEL to OPTOOUT and TACHSELECT to XG1
2. For ignition: remove R43 and R57, 330 ohm resistor to R26 - the other leg goes to IGBTIN, IGBTOUT - IGNJUMPER


Is there a recipe posted online for an ABA with a single coil and Hall effect dizzy? Somethign easy to follow?

Thanks,
Iain


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## ValveCoverGasket (Mar 20, 2002)

ijcameron said:


> Board mods: 1. For Hall sensor: TSEL to OPTOOUT and TACHSELECT to XG1
> 2. For ignition: remove R43 and R57, 330 ohm resistor to R26 - the other leg goes to IGBTIN, IGBTOUT - IGNJUMPER


did you jumper R43 after removing it?


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## need_a_VR6 (May 19, 1999)

ValveCoverGasket said:


> did you jumper R43 after removing it?


*This.*


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## ijcameron (May 17, 2001)

ValveCoverGasket said:


> did you jumper R43 after removing it?


Yes - R43 has a jumper soldered in place of the resistor.


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## need_a_VR6 (May 19, 1999)

Can you get the coil to fire by manually grounding it?


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## ijcameron (May 17, 2001)

Thanks Paul, i will check that, I have a couple of spare coils if I've fried the current one.

I looked again at the MS board (V3.0) and I am missing a coil driver at Q16 - I think it should be a VB921 or the later BIP 373. The space is blank - I built the board over 2 years ago and may have planned to use the external Bosch 7 pin dwell unit, I don't remember.

I'll dig up a VB921 coil driver, solder it in and see if that solves it.


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## ijcameron (May 17, 2001)

One last q. before I head to the shop and apply the "powah of retard":
How hard is it to set up the Jim Stim to register the output from the VB921? Like triggering an LED, or something.


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