Hall sensor failure

Timmerklits · Post by **Timmerklits** » Thu Apr 27, 2006 1:29 pm

Hello,

I have installed megasquirt 2 with V3 main board and a relay board on my Alfa 75 1.8. (Hall sensor, direct coil contro)

First I was starting my engine, but I saw no revs, en there was no ignition.

So I put A 1K resistor between the tach wire and the 5 V wire wich goes tot the TPS, so that the voltage pulled up.

I started again, and yes something around 250 revs, and also sometimes some spark fires.
Then I tried to set the base ignition timing right by turning the distribitur, I found a good point, but it was still not good enough for starting the engine.

So I played a bit with the cranking PW.

But after a while of testing, my tach signal wasn't there anymore.

So i checked a few things, also checked the megasquirt with the stimulator, and there was everything right.

But if I measure the voltage between the tach wire and the ground, and I turn the distribitur by hand, it gives a constant 5V voltage, (DC measurement), so I think here is the problem.

Ok I can change the hall sensor, but first I must now why it is broken?

Does anyone had such a problem, or knows what I done wrong.

Thanks

Nick

cashsaudio · Post by **cashsaudio** » Fri Apr 28, 2006 6:11 am

Timmerklits wrote:Hello,

I have installed megasquirt 2 with V3 main board and a relay board on my Alfa 75 1.8. (Hall sensor, direct coil contro)

First I was starting my engine, but I saw no revs, en there was no ignition.

So I put A 1K resistor between the tach wire and the 5 V wire wich goes tot the TPS, so that the voltage pulled up.

I started again, and yes something around 250 revs, and also sometimes some spark fires.
Then I tried to set the base ignition timing right by turning the distribitur, I found a good point, but it was still not good enough for starting the engine.

So I played a bit with the cranking PW.

But after a while of testing, my tach signal wasn't there anymore.

So i checked a few things, also checked the megasquirt with the stimulator, and there was everything right.

But if I measure the voltage between the tach wire and the ground, and I turn the distribitur by hand, it gives a constant 5V voltage, (DC measurement), so I think here is the problem.

Ok I can change the hall sensor, but first I must now why it is broken?

Does anyone had such a problem, or knows what I done wrong.

Thanks

Nick

Hey Nick

I had the same problem but didn't even want to mess with it anymore because I knew it worked just fine with the VR sensor enabled. Y don't you just switch it over to VR sensor instead of Hall sensor. It made it alot easier for me. Also lance on here said that the VR would work just fine. Hope this helps. Its just a couple jumpers to switch. and pull out one too.

Timmerklits · Post by **Timmerklits** » Fri Apr 28, 2006 7:42 am

Maybe that's the best sollution. The problem is, finding one.

But there must be some kind of reason that my hall sensor is broken now.

I'v chosen the hall sensor, because my opinion was that this is the easiast way. But apparently not.

greetz

cashsaudio · Post by **cashsaudio** » Fri Apr 28, 2006 9:58 am

Timmerklits wrote:Maybe that's the best sollution. The problem is, finding one.

But there must be some kind of reason that my hall sensor is broken now.

I'v chosen the hall sensor, because my opinion was that this is the easiast way. But apparently not.

greetz

I thought the same way but I've been dealing with the 92 dodge stealth and finally got it going yesterday and got it tuned in abit today. I just hope you can get it figured out. Im somewhat new to these MS but I'm learning on them fast so don't give up do alot of reading at www.megasquirt.info until someone knows what your problem could be. Thats how i get my things straighten.

Keithg · Post by **Keithg** » Fri Apr 28, 2006 10:41 am

Check the hall sensor a bit differently. When powered up it should show short and open when the tooth is out or in the gap.

KeithG

Posted by email.

Timmerklits · Post by **Timmerklits** » Sat Apr 29, 2006 9:56 am

I have found a inductive one now.

Installed it, played a bit with the cranking PW, and it started.

But I can't get it idling at 800-1000 rpm, I must hold it around 1500 rpm.

When running, and holding it at 1500 rpm, I see that my rev counter in my dashboard sometimes falls away, (his signal comes from the ground of the coil).
Also when I measure the high voltage of the coil, I see that it is around 20 kV but, sometimes drops done, less then 15 kV.

The rev counter in megatune stays 'constant'.

I think thats the reason I can't idle because there is something wrong with the ignition signal to the coil.

Does anyone know what may be wrong?

thanks

Nick

Timmerklits · Post by **Timmerklits** » Sat Apr 29, 2006 9:58 am

Can it be that I must adjust the two pots of hysteresis en zerocrossing?

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