Topic: Electronic Timing advance adjuter box thingie... someday...

[midnightcwby]

Ok, those of you guys that ACTUALLY READ my post on the MAP sensor adjuster I built, I feel sorry for you .  You’re probably tired of hearing from me by now, but I have another project I'm currently scouring the web for information on.  I'm proposing a DIY module that intercepts the ECM's electronic timing signal that is sent to the distributors ignition module and modifies it in such a way as to affect a set timing advance (or retard) of a set degree over the entire RPM range. This would basically give you the same effect as physically turning your distributor a set number of degrees advanced (or retarded) for what ever reason you can come up with from the comfort of your driver's seat.  It would make timing advances to take advantage of higher octane fuel a cinch!  The module I wish to build will have the same presets option as my MAP sensor adjustor module I made. So you can pick the number of degree's advance you would like to add for two situations, and with the flip of a switch you could go between the two of them, or go back to stock with the flick of another switch just as easily!  

Do you guys like this idea?  Let me know. If I get a lot of response, I'll really push the research of this thing and make a well-documented DIY package for anyone who wants info on it.  Again, I might also do a first come first serve, limited production of a few of these babies when I get one working the way I want it to.  We'll see if I can find enough information on what needs to be done to make one though, right now this is just theory and speculation.  If any of you have already stumbled on some information on how to make something like this, PLEASE PASS IT ON!  I would gladly review, modify, produce a prototype, test it, and pass on all my findings in an easy to read user friendly format for you guys to use.  

*Side Note: This would probably warrant a thermostat change for a cooler thermostat if you want to crank on the timing advance a lot for the same reasons that JET Performance asks you to use a cooler t-stat with their modules.

[littleredbeater]

put both in one box with the a/f gauge and youo'll have a winner. I'd buy one. of coarse I'm a sucker. haha JK

[Jeffy]

You know you can adjust timing with the CPS?

[midnightcwby]

That's the kind of info I'm looking for.  How far is the Crank position sensor allowed to adjust the timing on these ECU's?  Is that the best signal to intercept/modify to get a useful adjustment?  I'm going to hit the internet and look for some more answers. Thanks for the idea Jeffy!

[Jeffy]

I'd imagine a degree or 2 tops in either direction.  I've never tried it but I know it works.  You'd have to adjust it with a timing gun.  Although if you wanted to do it electrical, you'd need a box that could replicate the CPS signal and advance or retard it with a rhostat.  Although that would be more complicated.

[midnightcwby]

The type of signal I'm looking for is one that proportionally adjusts ignition timing with a variable DC voltage, not a pulsing current that’s signal is frequency modulated. I think a problem with using the CPS is that is produces a pulsating signal that’s frequency increases with engine RPM's. In order to "Modify" this signal and allow some kind of adjustment, I would have to create a very complicated digital electronic circuit or use one of my micro-controllers and write a program to increase the frequency of the original signal by a set (but still adjustable by the user) value.  This is not impossible by any means, just a lot tougher nut to crack than I would like to deal with for this project. I would most likely NOT offer any units for sale if I have to do this much work just to make one
I would rather tap into an existing feed back loop the ECM uses to make adjustments to engine timing using a variable DC voltage. This would use the same theory as the MAP adjustor and most of the same parts too! That would be a bonus. Plus it would be simpler, so there would be fewer parts to fail.
Let me know if any of you guys think of a signal the ECU uses like this that I can modify to make this box work!!!  Thanks!

[midnightcwby]

Ok, my head is swimming with Programmable Engine management systems I've been reading about on the internet all night. It looks like the end all answer to my quest for the most power and efficency out of one of these motors is MOST DEFINATELY a stand-alone engine management controller.  The MegaSquirt is a WONDERFULLY designed and supported option to this ends. It is fully user programmable/tuneable, completely replaces your current ECM, and uses Windows,Linux or OSX baised software to program it. It is so simple to program/tune. And the support offered to user is tremendous.  It does come at a cost though, it's a DIY kit. An expensive one at that. Currently, for the most advanced unit that can handle fuel injection and electronic ignition tasks, the price tag seems to sit at about $250. For me, this is very worth it because I'd love to assemble one of these just because I love the smell of solder fumes  Ok, I just really like electronics... a lot...  and programming...  So this baby is loads of fun for me!  But for the average do-it yourselfer out there, I'd say it would be a good idea to call a friend who is a electronics nut/computer programming geek for some help, maybe have him move in with you. It's a big project. Once completed, though, you would have full and total control over every aspect of your engine's state of tune.  Google searching MegaSquirt will bring up more information about this wonderful little invention than you would ever care to know about.  

With all of this said, I think I will end my quest for a quick, easy, DIY ignition timing module in favor of spending my spare time learning more about this standalone engine management system/building one...

[wrangler387]

^ before you can run ignition on megasquirt you will need to either A. get the stock jeep stuff to work in MS (stock runs off of both the crank and the distributor to determine engine location) or B. set-up EDIS or some other form of ignition on it. Definately buy yourself a wideband o2 sensor kit, no narrow band air/fuel guage stuff.

If you do go through with this and get option A. to work that would save me a lot of trouble in a few months, and there is a few people looking to use the stock 4.0 sensors (same shit as the 4 except it has more windows for the 2 extra cyclinders). So if they or you get the code right to allow you to control ignition properly using the stock stuff that would be awesome, for i plan to put megasquirt on my jeep this summer and then hopefully have it turbocharged this winter.

[jackhammer]

the evil geneous is at work

[littleredbeater]

I came real close to using a megasquirt on the last turbo car I built but plyed it safe and went with a manufactured unit. If you do go the megasquirt route please take lots of pics and document it as well as you can because even at $250 this mod is invaluable. I like how the software pretty much self tunes with use of a labtop and some real world driving. According to what I've read you can let it run as you daily drive for weeks and it will eventually tune everything to virtually perfect levels across the board. And never having to pay dyno fees...... can't beat that. So definitly let us what your progress here if you can manage it. Coolness.......

[jwrape]

I'd imagine a degree or 2 tops in either direction.  I've never tried it but I know it works.  You'd have to adjust it with a timing gun.  Although if you wanted to do it electrical, you'd need a box that could replicate the CPS signal and advance or retard it with a rhostat.  Although that would be more complicated.

I didn't know that the throttle position sensor was adjustable.
If mine was adjusted incorrectly when i put the tranny back be the reason why I am running so rich and spitting out the tail pipe after every gear?

[Jeffy]

I didn't know that the throttle position sensor was adjustable.
If mine was adjusted incorrectly when i put the tranny back be the reason why I am running so rich and spitting out the tail pipe after every gear?

CPS not TPS.

It's not adjustable in stock form.  People slot the mounting holes.

[jwrape]

I didn't know that the throttle position sensor was adjustable.
If mine was adjusted incorrectly when i put the tranny back be the reason why I am running so rich and spitting out the tail pipe after every gear?

CPS not TPS.

It's not adjustable in stock form.  People slot the mounting holes.

Which direction would I move it to advance the timing? up or down, towards the top of the bellhousing or towards the bottom? Would there be any ill affects?

[Jeffy]

Look at the way the flywheel rotates, counter that would advance the timing.  Move it in the direction of the flywheel and that would retard the timing.

[jwrape]

Look at the way the flywheel rotates, counter that would advance the timing.  Move it in the direction of the flywheel and that would retard the timing.

Hmm might have to try that then.
Thanks