hey guys, remote start, tach signal
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=112196
Printed Date: May 17, 2024 at 10:23 PM
Topic: hey guys, remote start, tach signal
Posted By: flybyu
Subject: hey guys, remote start, tach signal
Date Posted: March 08, 2009 at 4:44 AM
A friend and i are having some custom remote start units made for our needs. We had to tell them the frequency (hz) range we needed for tach wire shutoff. Thats a range of 10hz and 30hz. here is the problem were having now, the unit starts the vehicle as it should and shuts down at the right rpm like it should. But if the vehicle fires and dies, the unit will try again and starts the vehicle the second time and runs for 30 sec and shuts off and never tries again. It's something to do with the tach wire. were using an injector as a signal. Could on the restart of the vehicle the injector go into a duty cycle producing hz and going above are tach shutoff.
Replies:
Posted By: KPierson
Date Posted: March 08, 2009 at 4:53 PM
You would be best off using a frequency meter to verify the perameters and operation of the fuel injectors. Most lower end Craftsman meters will read frequency (the $30 ones) and all higher end meters should read frequency. Who is making the custom units? Have you verified with them that the restart function was tested and verified to work? ------------- Kevin Pierson
Posted By: loneranger
Date Posted: March 08, 2009 at 5:09 PM
Shouldn't you could keep to the original thread with this post? ------------- Ideal - cmon dude, add to topics in a useful manner, not stuff that is obvious.
Story - Phzzzt! Hey, what happened?! ... Isn't it obvious?
Moral - Never dismiss the obvious.
Posted By: dswift
Date Posted: March 09, 2009 at 6:41 PM
Sounds like bad tach to me. Are you on injector 1? Should be closest to the timing belt. ------------- "dont ground out!"
Posted By: flybyu
Date Posted: March 09, 2009 at 10:35 PM
What we think is happening is the tach sensing software is not resetting itself and as soon as it starts on the second attempt it doubles and shuts it off for overreving. What do you think? so we have to wait another 2 weeks for more prototypes.
Posted By: KPierson
Date Posted: March 10, 2009 at 5:34 AM
Have you verified the tach signal is not changing with a meter? Thatt will the only way to really know what is going on. What exactly is your application and why did you have to have custom modules made? ------------- Kevin Pierson
Posted By: Chris Luongo
Date Posted: March 10, 2009 at 10:46 AM
I suppose the best thing you'll want to do is contact your manufacturer and ask them how the circuit is supposed to work, and if they have any ideas why it's behaving incorrectly.
In the meantime, can you find another tach source to try? You said you were using an injector.
Try a coil pack, or even a camshaft position sensor or crankshaft position sensor. Pretty much anything that makes a pulse while the engine is rotating would be worth a try.
Sorry I couldn't be of any more help.
Like the other guys, I'm very curious about what you're doing too. Are you getting just a few remote starters for some kind of special vehicle of your own............or are these something you're going to be reselling?
If you're a manufacturer or distributor or anything like that, I'm always looking for new opportunties, beta testing, and so forth. Professional installer with nearly ten years' experience, particularly in installing remote starters.
Posted By: wiringfool
Date Posted: March 12, 2009 at 7:53 PM
here is some food for thought I have fooled remote starters on the bench to think its getting a tach signal with this info you should be able to determine the frequency I have used a signal function generator and adjust to approx 3volt a.c. voltage and play around you'll get it
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wiringfool eieioztztzt
Posted By: flybyu
Date Posted: March 12, 2009 at 10:04 PM
Chris Luongo wrote:
I suppose the best thing you'll want to do is contact your manufacturer and ask them how the circuit is supposed to work, and if they have any ideas why it's behaving incorrectly.
In the meantime, can you find another tach source to try? You said you were using an injector.
Try a coil pack, or even a camshaft position sensor or crankshaft position sensor. Pretty much anything that makes a pulse while the engine is rotating would be worth a try.
Sorry I couldn't be of any more help.
Like the other guys, I'm very curious about what you're doing too. Are you getting just a few remote starters for some kind of special vehicle of your own............or are these something you're going to be reselling?
If you're a manufacturer or distributor or anything like that, I'm always looking for new opportunties, beta testing, and so forth. Professional installer with nearly ten years' experience, particularly in installing remote starters.
These are actually for snowmobiles. and they have coil on plugs, so very difficult to get good tach source there
Posted By: KPierson
Date Posted: March 13, 2009 at 6:32 AM
With a coil on plug system you have options - you can grab a tach at each coil, at a fuel injector, or at the crank angle sensor. With your frequency range though the crank angle sensor would be out, but you should still be able to use a coil or a fuel injector. So why again were the units custom programmed? 11hz is the range that many, many vehicles idle at. Were you just looking for a more fitting shutdown frequency? ------------- Kevin Pierson
Posted By: Chris Luongo
Date Posted: March 13, 2009 at 9:07 AM
flybyu wrote:
These are actually for snowmobiles. and they have coil on plugs, so very difficult to get good tach source there
Many (or most?) modern cars are built that way too.
So you're saying that on top of the engine cylinder, you've got a spark plug, then the coil sits right on top of it.....so it doesn't have regular spark plug wires, right?
That's ok. Doesn't the coil have regular automotive-style wires going to it? Two or three wires plugged into it? One of those should be AC to cycle the coil.
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