tach spike conquered!!!!!!!!!!

floppy · Post by **floppy** » Tue Aug 29, 2006 9:42 pm

Finally, I'm rid of the tach spike beast!!!
used peter florance's circuit and it all went away...
never did find the download(and I looked a lot!!)
Found it in some vast search of spikes

Suddenly everything seems to respond as it should and it's running fairly well, course now I'll be starting all over...

Also found that bumping the PWM up to 85 made a huge difference in how it runs, instead of starting at 75 for low Z and going down??

Still haven't figured out how to get the AE bars to move more than just a very small amount, I would think that if you hit the throttle all the way with MT on but not running that it would simulate AE by moving up the scale(tps or MAP)???

What a Great threshold to pass, Peter if our paths ever cross pints are on me. Thanks, Mark

Peter Florance · Post by **Peter Florance** » Wed Aug 30, 2006 4:56 am

floppy wrote:Finally, I'm rid of the tach spike beast!!!
used peter florance's circuit and it all went away...
never did find the download(and I looked a lot!!)
Found it in some vast search of spikes

Suddenly everything seems to respond as it should and it's running fairly well, course now I'll be starting all over...

Also found that bumping the PWM up to 85 made a huge difference in how it runs, instead of starting at 75 for low Z and going down??

Still haven't figured out how to get the AE bars to move more than just a very small amount, I would think that if you hit the throttle all the way with MT on but not running that it would simulate AE by moving up the scale(tps or MAP)???

What a Great threshold to pass, Peter if our paths ever cross pints are on me. Thanks, Mark

Pints! I'm there!

I'm guessing the download feature is still broken.

I'll post it one of my sites and post it with the link so it can be found by searching.
Someone emailed me for it (I hope I remembered to email it to them) and I had a heck of a time finding it. Lots of references to it on the web (Turbobricks and Alfa) but not the actual file. It's on my PC at work and I'll get it to an accessable place.

Note I think it's more complicated than it needs to be, but I just ran out of time to engineer it any further.

Glad it helped!

Keithg · Post by **Keithg** » Wed Aug 30, 2006 5:05 am

please post a link here to this solution.

KeithG

Peter Florance · Post by **Peter Florance** » Wed Aug 30, 2006 6:21 am

Keithg wrote:please post a link here to this solution.

KeithG

Peter Florance's Tach Circuit (what it tends to be called on the web)

Sorry for the long URL:
http://www.firstfives.org/faq/ljet/mega ... 021505.PDF

Dr.Hess · Post by **Dr.Hess** » Wed Aug 30, 2006 6:21 am

Yes, please. More details. I get a spike occasionally too.

Peter Florance · Post by **Peter Florance** » Wed Aug 30, 2006 5:25 pm

Dr.Hess wrote:Yes, please. More details. I get a spike occasionally too.

This is for fuel-only systems that are triggering from the negative terminal of the coil. I ran with it for a couple of years with nary a hicup.

Like I said, it's too complicated but I ran out of time to make it simple and elegant.

The PDF refers to V2.2 board components

http://www.firstfives.org/faq/ljet/mega ... 021505.PDF

Fritz-XT600 · Post by **Fritz-XT600** » Wed Aug 30, 2006 7:05 pm

V2.2 sch

Peter sch

Changes:
- D5 => 4.7k resistor
- R10 => 4.7k resistor
- include Dave Cap betwen R10 and D3

Some questions:
- D8 must be changed from 5.1V to 4.1V ??
- What about C11 and C12??

Thks

Dr.Hess · Post by **Dr.Hess** » Thu Aug 31, 2006 6:41 am

Thanks for posting that. I don't think that's what's causing mine. I'm using VR off the factory dizzy with 2 teeth cut out and I trigger 2 igniters, basically, to two waste-spark coils. Spikes just happen. Sometimes at high RPM sometimes at lower RPM's. At higher RPM (6-7K), the spikes might register as 10-20K. At lower RPM's, they might register as 6K. Doesn't seem to be associated with anything else like my VVT, which comes on at 4400 and off at 4300. Oh well.

msoultan · Post by **msoultan** » Thu Aug 31, 2006 8:56 am

Just so you guys know, I'm still running Peter's mod and it works great on my 78 vw bus (40,000 miles later). I am still forever grateful to Peter for that mod. It saved my life! ;)

thanks,
mike

Fritz-XT600 · Post by **Fritz-XT600** » Thu Aug 31, 2006 9:29 am

msoultan wrote:Just so you guys know, I'm still running Peter's mod and it works great on my 78 vw bus (40,000 miles later). I am still forever grateful to Peter for that mod. It saved my life! ;)

thanks,
mike

Asking again, as I think the questions are not clear on my last post:

D8: can I keep the 5.1V, or it must be changed to 4.1V?

C11 and C12... it`s not show in the Peter schemattic, and not in the picture in the PDF... so, I need to get it off de board??

thanks for your help..

Peter Florance · Post by **Peter Florance** » Thu Aug 31, 2006 9:55 am

Fritz-XT600 wrote:V2.2 sch

Changes:
- D5 => 4.7k resistor
- R10 => 4.7k resistor
- include Dave Cap betwen R10 and D3

Some questions:
- D8 must be changed from 5.1V to 4.1V ??
- What about C11 and C12??

Thks

They can be left in or taken out. Should not make any difference either way.

Peter Florance · Post by **Peter Florance** » Thu Aug 31, 2006 9:57 am

Oh and 5.1V zener should be fine as well

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tach spike conquered!!!!!!!!!!

tach spike conquered!!!!!!!!!!

Re: tach spike conquered!!!!!!!!!!