Volkswagen coil driving

qbngolf · Post by **qbngolf** » Wed Apr 19, 2006 5:13 am

im telling you i already tried that, it either has to be a hardware mod or its just not possible, the megasquirt doesnt like that sensor for some reason. im just telling you this because it took me a while to figure this out and i dont want to see other people wasting their time on something that has already been done and is known to not work. on that link that i posted before, there is a member called cndub, he figured out how to get it working on a vr6 it took him some time but im pretty sure he got it. your best bet would be contacting him and asking him how to do it. im not sure if it would be the same sensor but its worth a shot. i also tried giving it 5 volts from the proto area and that didnt work either. i didnt try wiring 1=2 together like redjetta said but i wouldnt think it would make a difference

redjetta · Post by **redjetta** » Wed Apr 19, 2006 6:11 am

were you using the VR circuit or the Hall circuit? Europe or NA?

GodSquadMandrake · Post by **GodSquadMandrake** » Wed Apr 19, 2006 7:31 am

From this thread:
http://www.msefi.com/viewtopic.php?t=15 ... 17935e2e46

Like you say, I fed pin 24 with +12V, and took the T68/67 signal through a spare pin into XG1. This way the opto circuit runs inverted (known as schematic 2 in the manual, or as midnightGLI's schematic on the vortex). As for idle, i simply used a higher power transistor (TIP122). ZTX688 should be enough though.

Basil

GodSquadMandrake · Post by **GodSquadMandrake** » Wed Apr 19, 2006 7:34 am

So it sounds like basil took wired 1+2 and put them together inside Megasquirt like Redjetta said. I don't really understand what he is saying, basil gets too technical. But he put two wires into megasquirt and it sounds like they are wired together.

My only thought would be this. The +12v provides the voltage for the waveform, and then the signal wire shorts it out when a tooth on the trigger wheel goes by. So this way you get a square wave form of 0v and +12v.

Maybe it's not a VR sensor at all. Maybe it's just a magnet that closes a circuit between two wires?

I guess this could be verified by taking out the VR sensor and verifying if those two wires have 0 ohms of resistance when you touch a wrench or something to the end of the magnet. If that is the case then it's definetley not a VR sensor.

qbngolf · Post by **qbngolf** » Wed Apr 19, 2006 8:32 am

pretty sure i tried it both ways, vr and hall. i definately tried hall. also it is a NA

vlopsahl · Post by **vlopsahl** » Wed Apr 19, 2006 9:08 am

GodSquadMandrake wrote:So it sounds like basil took wired 1+2 and put them together inside Megasquirt like Redjetta said. I don't really understand what he is saying, basil gets too technical. But he put two wires into megasquirt and it sounds like they are wired together.

It is not that complicated. I have not tried this myself jet, but I will do in some weeks. Maybe I can try to explain Basils solution. You brake the XG1 â€“ XG2 on the V3-board. Then you feed the signal in there through one spear wire on the DB37 . Then you fed pin 24 on the DB37 with 12V+. You also fed one of the three wires on the sensor with 12V+. The sensor then have 12V+, signal out (to directly to XG1) and ground.

I have been searching in ETKA (VAG parts catalog) and there is, as many have said, many different (different partnumbers) crank sensors. I am going to try my Euro ABF sensor. If I am not able to make this one work I will try one form the Euro 1,8T AEB.

jassem99 · Post by **jassem99** » Wed Apr 19, 2006 9:29 am

I don't think the following will be of much help to you if your crank sensor is VR, but for my hall sensor here's what i found:

The VW hall and VR crank sensors are identical in outward appearance, except that the hall model has a slot running along the side of the sensor body. And IIRC the hall 3-wire connector and VR connector are not compatible, so you can't use one instead of the other on an OEM harness.

The ABF hall sensor should be fed +12V on pin 1 sensor (red colour). If pin 3 is grounded, then the square signal will be generated at pin 2 (green wire). That is the signal you feed to the MS.

But you can't feed this signal into pin 24 of the MS as on the standard schematic. You need to run the opto in inverted mode. To do this, feed pin 24 of the MS +12V, and then run XG1 (after cutting XG1-XG2) to the crank signal (via any of the spare pins like 25, 27, 29, 31).

Edit: vlopsahl beat me to it by a few minutes. His explanation is spot on by the way.

Basil

GodSquadMandrake · Post by **GodSquadMandrake** » Wed Apr 19, 2006 9:33 am

vlopsahl wrote: You brake the XG1 â€“ XG2 on the V3-board. Then you feed the signal in there through one spear wire on the DB37 . Then you fed pin 24 on the DB37 with 12V+. You also fed one of the three wires on the sensor with 12V+. The sensor then have 12V+, signal out (to directly to XG1) and ground.

I don't think I touched XG1 or XG2 on my V3. Those are hall sensor inputs right? I wired my board up for VR only, even though I have the hall sensor circuitry installed.

On the instructions:
http://www.megasquirt.info/ms2/V3assemble.htm Step 52 it says:

For the VR sensor:
Jumper VRIN to TACHSELECT on the bottom side of the PCB (near the DB37, opposite the heat sink.)
Jumper TSEL to VROUT (Or VROUTINV if you want the VR input to be inverted) on the bottom side of the PCB, near the center.
OR (Do NOT install both sets of jumpers, chose one set or the other!) For the Hall sensor, optical sensor, coil negative terminal or points:
Jumper XG1 to XG2 on the bottom side of the PCB, near the 40 pin socket,
Jumper OPTOIN to TACHSELECT on the bottom side of the PCB, near the DB37 connector, opposite the heat sink.
Jumper TSEL to OPTOOUT on the bottom side of the PCB, near the center.

So I only wired up the VR part. Should I switch my tachselect and tsel for Hall operation?

I don't understand why I feed +12v into pin 24, that's my tach signal wire, but i'll do it anyway. How do I jumper XG1 to one of the extra pins on my DB37? I have 4 extra wires that I can use, I just don't know how to hook them up. Their plugged into the D-shell connector already too.

qbngolf · Post by **qbngolf** » Wed Apr 19, 2006 11:08 am

you have your board wired up for vr but his crank sensor is a hall sensor. thats what i assumed mine was and no go for me

bens_cab · Post by **bens_cab** » Wed Apr 19, 2006 11:45 am

got my tps running backwards i may just use a mk3 throttle body as these fit well

no probs with my vr sensor getting all the correct rpm signals on cranking

just need to sort out my fuel pump relay which i think has packed up that or my wiring sucks cos i never touched the fuel pump

just trying to set the trigger settings at the moment does having 4 coil on plugs effect the triggers ie do i use more than trig A and B

using v3 msns 029i