No Tach Signal

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Yodapom
MegaSquirt Newbie
Posts: 12
Joined: Thu Dec 29, 2011 7:55 pm

No Tach Signal

Post by Yodapom »

Hi All,

I have a MS2 V3.0 with a relay board which Im in the process of trying to get the car started. I have all the other sensors working great but have not had a tach signal.

Im starting by just getting the tach directly from the Negative on the coil (easiest way on my car) this meant I wasn't able to check the tach from the stim.

I have the D1 in place and the zener diode in D2 (Reversed).

I have uploaded the .s19 onto the board and ran the tachref.exe with a nil response.

Although i don't have an oscilliscope i have checked with a meter and there is variation with the voltage both the coil and at the relay board. I have a DIYAutoTune cable between this and the v3.0 some I have assumed the board is getting a signal.

Any ideas or help?

Steve
Yodapom
MegaSquirt Newbie
Posts: 12
Joined: Thu Dec 29, 2011 7:55 pm

Re: No Tach Signal

Post by Yodapom »

In further research I have found U3 in the wrong way round!

I have now installed it correctly with no luck.

Will keep posted once new one arrives.

cheers

Steve
trakkies
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Joined: Tue Dec 30, 2008 3:06 am
Location: SW London, UK

Re: No Tach Signal

Post by trakkies »

Solder a jumper across the zener (D2) and your stim should work. Remove the jumper before connecting to ignition.
Dave P, London UK.
Rover V-8
MSII V3
EDIS
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Yodapom
MegaSquirt Newbie
Posts: 12
Joined: Thu Dec 29, 2011 7:55 pm

Re: No Tach Signal

Post by Yodapom »

Ive tried the jumper with no success.

I think having the U3 in wrong has buggered it.

Will have to wait for new one to arrive.

Cheers

Steve
Yodapom
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Posts: 12
Joined: Thu Dec 29, 2011 7:55 pm

Re: No Tach Signal

Post by Yodapom »

Well Ive replaced my U3 and still do not have any signs of Tach.

I have treid bypassing the Zener for testing from the Stim. Its powered through mains so don't think I have a power overridding issue.

Any Ideas?

Cheers

Steve
Matt Cramer
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Joined: Sat Jul 03, 2004 11:35 am

Re: No Tach Signal

Post by Matt Cramer »

Does the problem happen just on the car, or can you duplicate it on the Stim?
Yodapom
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Posts: 12
Joined: Thu Dec 29, 2011 7:55 pm

Re: No Tach Signal

Post by Yodapom »

I had the problem with the car and the Stim.

I am now trying to get it to work solely working on the Stim.

I have the JimSTIM and have checked that with the LEDs and it is outputting an RPM Signal.
Matt Cramer
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Posts: 2951
Joined: Sat Jul 03, 2004 11:35 am

Re: No Tach Signal

Post by Matt Cramer »

Could you post a copy of your MSQ? Could be something like an over-aggressive noise filter.
Yodapom
MegaSquirt Newbie
Posts: 12
Joined: Thu Dec 29, 2011 7:55 pm

Re: No Tach Signal

Post by Yodapom »

This is the latest .msq that Im using.

Cheers

Steve
CurrentTune.msq
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Matt Cramer
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Joined: Sat Jul 03, 2004 11:35 am

Re: No Tach Signal

Post by Matt Cramer »

I see you have it set up for wheel decoding but have not set a missing tooth number. Exactly what sort of ignition are you using?
Yodapom
MegaSquirt Newbie
Posts: 12
Joined: Thu Dec 29, 2011 7:55 pm

Re: No Tach Signal

Post by Yodapom »

At the moment I am only trying to run off the coil!

I have a 36-1 wheel to go on in the future but the engine has to come out for that.

Where/what should be changed?

Cheers

Steve
Matt Cramer
Super Squirter
Posts: 2951
Joined: Sat Jul 03, 2004 11:35 am

Re: No Tach Signal

Post by Matt Cramer »

Turn off the 12 tooth wheel decoder.
Yodapom
MegaSquirt Newbie
Posts: 12
Joined: Thu Dec 29, 2011 7:55 pm

Re: No Tach Signal

Post by Yodapom »

Success!!!

Thanks for all your help Matt.

Car actually started after one revolution and idled!

Cheers

Steve
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