Author Topic: strange triggering  (Read 27271 times)

Offline Poliux

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Re: strange triggering
« Reply #15 on: May 08, 2013, 07:14:56 am »

Offline Poliux

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Re: strange triggering
« Reply #16 on: May 08, 2013, 07:17:46 am »
what is starnge about it, that it's a directional sensor - e.g. works only in certain possition, if you turn it 90deg - signal is gone

Offline Poliux

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Re: strange triggering
« Reply #17 on: May 08, 2013, 07:25:02 am »
Allso you can try changing main ground cable location, like firewall.

Offline Marty

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Re: strange triggering
« Reply #18 on: May 08, 2013, 03:00:55 pm »
I was thinking about this last night, and came up wondering if the "Engine speed sensor" is the same model as the "TDC sensor" on these Audis. The failure threshold seems to be just about 3200 rpm's for many people, and I'm guessing that me and several others are using a "TDC" sensor...
- Maybe this sensor gets saturated and fails due to the (60x) triggering increase when using it this way(?).

Today I'm going to test an ABS sensor from the Audi and see what the outcome is. This one measures close to 1300 ohms FWIW, and is likely a very 'precise' sensor given it's application. I have a bracket half made so far, and tonight I'll finish it up and give it a try.
This could make a ton of difference, thanks for the thought!

I have relocated my battery to the trunk:
- 2g (6mm) chassis ground in the trunk,
- 2g (6mm) from the battery to the engine bay (chassis, ground)
- 2g (6mm) engine block to chassis ground

Offline Marty

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Re: strange triggering
« Reply #19 on: May 09, 2013, 01:40:09 am »
well... that didn't help. with the ABS sensor I could only get 2999 rpms before it crapped out.

Offline Marty

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Re: strange triggering
« Reply #20 on: May 09, 2013, 01:51:32 am »
(Edit)
@MWFire, for the sectrig filter: is it the "sectrig maximum value" field you are referring to set at 250?
« Last Edit: May 09, 2013, 06:09:28 am by Marty »

Offline Poliux

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Re: strange triggering
« Reply #21 on: May 09, 2013, 07:44:50 am »
well, sad to hear that it  didn't help to cure that missfire problem :-[
what ignition coils are you using?Some of them are injecting ground noise into sensor gnd, because sec. winding groud has an internal connection to sensor gnd

Offline Poliux

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Re: strange triggering
« Reply #22 on: May 09, 2013, 07:49:53 am »
all main ground paths 6mm2, and vems main ground connected with the same thickness cable? eg 6mm2? (5pwr gnds-> 6mm2 cable -> intake manifold or firewall?

Offline Kamuto

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Re: strange triggering
« Reply #23 on: May 09, 2013, 01:15:59 pm »
I was thinking about this last night, and came up wondering if the "Engine speed sensor" is the same model as the "TDC sensor" on these Audis. The failure threshold seems to be just about 3200 rpm's for many people, and I'm guessing that me and several others are using a "TDC" sensor...
- Maybe this sensor gets saturated and fails due to the (60x) triggering increase when using it this way(?).

Today I'm going to test an ABS sensor from the Audi and see what the outcome is. This one measures close to 1300 ohms FWIW, and is likely a very 'precise' sensor given it's application. I have a bracket half made so far, and tonight I'll finish it up and give it a try.
This could make a ton of difference, thanks for the thought!

I have relocated my battery to the trunk:
- 2g (6mm) chassis ground in the trunk,
- 2g (6mm) from the battery to the engine bay (chassis, ground)
- 2g (6mm) engine block to chassis ground
your ground cables are too weak, engine block  chasis ground must be ~20mm or something, battery to chasis 20mm too, and then, ecu----cylinder head 6mm are ok. rpm problems means poor wiring, poor grounding..
Vems installer in Lithuania
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Offline Marty

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Re: strange triggering
« Reply #24 on: May 09, 2013, 04:01:30 pm »
Here is the size of ground leads, I believe they are sufficient. I have one grounded at the back, and one at the front, plus the block ground.

- In the US this is 2gauge, with diameter 6.35mm.


Here's a shot of my coils; they are LS2 style high output coils.
« Last Edit: May 09, 2013, 04:08:44 pm by Marty »

Offline Marty

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Re: strange triggering
« Reply #25 on: May 09, 2013, 05:24:45 pm »
- Also my ignition coils are grounded to the battery. That may be a poor choice, so this evening I guess I'll 'chassis' ground the coils and double check the ECU ground.
I'm using the VEMS V3 harness with relays, so all of the ground leads are secure; I'll verify my ground point though, maybe some improvement can be made there. 

Offline Kamuto

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Re: strange triggering
« Reply #26 on: May 09, 2013, 09:37:00 pm »
Here is the size of ground leads, I believe they are sufficient. I have one grounded at the back, and one at the front, plus the block ground.

- In the US this is 2gauge, with diameter 6.35mm.


Here's a shot of my coils; they are LS2 style high output coils.


:D when I wrote 20mm I mean 20 square mm your grounds are more than enough
Vems installer in Lithuania
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Offline Kamuto

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Re: strange triggering
« Reply #27 on: May 09, 2013, 09:38:20 pm »
Here is the size of ground leads, I believe they are sufficient. I have one grounded at the back, and one at the front, plus the block ground.

- In the US this is 2gauge, with diameter 6.35mm.


Here's a shot of my coils; they are LS2 style high output coils.


:D when I wrote 20mm I mean 20 square mm your grounds are more than enough
i know others are using capacitor on these coils, because these ones are noisy
Vems installer in Lithuania
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Offline MWfire

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Re: strange triggering
« Reply #28 on: May 09, 2013, 11:56:32 pm »
You are going in wrong direction. Your problems are only with sloppy cam belt(so sec trigger is moving form 355 to 360+ deg).
Just change sec trigger edge and also primary trigger to get exact TDC.

Offline Marty

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Re: strange triggering
« Reply #29 on: May 10, 2013, 12:09:45 am »
Can you be a little more descriptive?
- if you think it's belt slop, should I tighten the belt?
And you are suggesting to change both cam and crank sensor edges to the opposite of what they are currently? I was not clear based on the wording.

Also I posted a question to you above about the sectrig filter
"for the sectrig filter: is it the "sectrig maximum value" field you are referring to set at 250?"