devitek

I was just curious. I took apart an old discman last night to get caps, and I think I found 1 33uF 10v. How important is the value on it? I got tons of 22uF, 47uF, 2.2uF, 3.3uF, and so on.

gsl-se addict

iTrader: (3)

The exact value doesn't really matter. Just use the 22uF if you have a pair.

devitek

Ok. Here's today:

I soldered in the 4 caps and 2 diodes. Plugged everything in. The idle was still rough, but the car was running better than before. I drove about 20 miles on it before it started to annoy me again with the stumbling.

At my friend's place (VashtheStampede on here), he was trying to get his '91 running. We grabbed his timing light and hooked it up to my car with the TT running, and we couldn't find any way to really set it. Seemed like the timing was still bouncing around. We went back to the stock setup and adjusted leading and trailing timing on it and pretty much left it at that. So, there is improvement, but there's something still missing.

Looking at his car, I noticed that the leading coil pack is up near the headlight. I'm thinking there might be a reason for that...RF interference! We have our coil pack near the dizzy, near the trick box, near all the wiring for the trick. Tomorrow I will try the aluminum foil shielding idea. My dad says that the shielding needs to be grounded, so I'll do that too. I'm also going to shorten all my wires to their bare minimum. But Kent, it looks like your recent idea might be helping alot. If I can get it shielded, I'll go back to the timing light to see what we get.

gsl-se addict

iTrader: (3)

Dave:

- Did you check the to see if the timing advances when you increase RPM? The mark should move away from you.

- Did you use the 22uF caps, then?

- The 2nd gen coil power and the TT power are connected to the stock +, then? Is the condensor (silver cylinder on the dizzy) connected?

- On the shielding, it does need to be shielded to work properly.

It sounds like we are making progress, but we are still missing something.

From the testing Rob and Paul did before, they found:

- noise on output with coil connected
- retrigger of circuit sometimes
- timing very retarded with R2, slightly retarded without R2
- timing retarded instead of advance with R2. Without R2, advanced normally.
- without R2, there is no max pulse, so coil pack gets hot.

These may be a result of one cause or not. Maybe the mods that you did corrected some of these. It may be hard to check without a scope, though.

I am not sure what is going on as the old circuit didn't seem to have these issues. The old circuit is nearly identical with some difference in the logic so there is the max pulse limit. The new logic works correctly without the coil connected. The coil seems to be causing some issues.

Give the shielding thing a try and see if you can see what the timing is doing. Hopefully we will find something that will spark some new ideas to try. Thanks for the help. I really appreciate it. If you have MSN, we could maybe chat and discuss things during testing. Maybe it would help.

Kent

H4Inf

hi i think Kent meant to say that the shielding does need to be grounded for it to work.

I'm looking forward to hearing the results of further testing!!

Cheers,

Paul.

dantheman

iTrader: (4)

I just wanted to say thanks to all of you guys who are working on this issue. It makes me want to take some EE classes instead of my Industrial Distribution and ME classes.

Keep up the good work! If anyone needs something non-electrical done I might be able to help. :P

devitek

For the timing, we weren't able to even see the marks with increased RPMs. That we'll have to try again.

I did use 22uF caps.

Both power leads are connected to + on the stock coil. I need to check for that condenser.

I'm pretty pressed for time today, got a birthday party for my wife and daughter to attend to. I'm going to take a look at it in a few, maybe try that shielding and report back.

devitek

Ok, condenser is connected.

Shielded all the wires and the box. No change. I'm stumped. I can't get to the timing light today, but it really wouldn't make much difference. There's just something we're missing here.

DeRFmAn

You guys are working hard trying to figure this out for us. Wish there was something I could do to repay your help.

devitek

Just keep interested in it, that's all the support we really need. I'm sure we're going to figure it out eventually.

Funny thing happened. I got out the old 2nd gen pack that shot craps to do a direct j109 to coil setup, and it did nothing. I think the coils, not the ignitor, is what died on me before. I'm going to look up how to test the ignitor without having it in the car, but it's possible that the simple TT was not to blame for this misfortune. Dunno, have to keep researching.

gsl-se addict

iTrader: (3)

Thanks for the support, guys. Thanks to all the guys helping with testing as well. I am thinking that I may just pick up an o-scope on ebay. There are a few listed in France and aren't too expensive. I can have my dad ship up my 2nd gen coil pack and such. This may be the easiest way to get this tested and done. I am out of ideas as to what is going on, so poking around with an o-scope seems to be the only solution. My neighbors will probablly be wondering what is going on with the sound of those spark plugs buzzing, though. I'll see what I can come up with.

Kent

dantheman

iTrader: (4)

Shoot, if you were local to me I would loan you my o-scope that has been sitting in my attic. I can bairly use the dang thing.

Wish I knew you needed one anyway. . . . I could have picked you up one over spring break. $30 for one with a camera, $25 for one without. They were working, but I don't know how accuratly.

devitek

Well hey, I'm just up in Kansas. You wanna work something out? If I have an o-scope, I can do the testing here. It also seems like I have a little more time to work on this than most others, so we could get some quick results. But, fair warning, in one month my wife will have a baby and I won't have nearly the time, so we should probably work quickly on this.

dantheman

iTrader: (4)

I am down in Texas. Those scopes were from a Military Surplus store up in Los Alamos called the Black Hole. Shipping would cost more then the scope. Contact them and I am sure they would sell you a working one and ship it!

devitek

Kent,

Can a software o-scope be used? Say on a laptop? If so, do you know how one goes about making probes for that kind of setup?

gsl-se addict

iTrader: (3)

I am taking a look at those too. I think you can get little data acquisiton boards that then connect through USB or serial. I'll look some more and let you know. We don't need anything too fast for this.

devitek

Most, if not all of the software o-scopes I've seen so far seem to get their signal from the sound card input. I asked about probes because you would have to make something up custom to use that sort of input. If we could do that, I could stop wasting time on ebay today and just start working on a probe adapter. Plus, the information obtained from software can be easily recorded and sent back and forth between us which would make things alot more clear across the board. I've been searching all morning for the specs for making the probes, but no one seems to know how to do that. Seems simple enough to me, but I want to be sure I do this right this time.

gsl-se addict

iTrader: (3)

Hmm. It appears that the sound card based scopes are limited to 2v. Here is more info: http://www.virtins.com/ . If you want to try something like this, we could use a couple of op-amps setup to knock the voltage down by whatever factor. I need an o-scope anyway, so I will probably go ahead and pick one up. The o-scope I used before was at my university. I don't have one at home.

devitek

I just won an o-scope on ebay. I wasn't even being serious when I bid on it. $20? Oops.

gsl-se addict

iTrader: (3)

Well, can't beat $20. Which one did you get? O-scopes are nice to have. You can really check out a lot of electrical stuff with them.

devitek

It's an older one I think, a Fairchild 701. Looks like it should do the trick, though. If not, well, then I'm out $20!

devitek

I got bored today after working with simulation software (so far getting the same results as you, Kent). So I decided to rig up my old, blown out coil pack for the direct direct fire setup. For those that know, that involves removing the 2nd gen ignitor from the equation and using the coil pack directly, just maintaining the ballast resistor inside. It didn't work.

So, I thought maybe that coil had gone bad. Switched it with the newer one. Still didn't work.

That really only left one thing. The ballast resistor! So, I took the one from the working coil pack and joined it with the old coil, and voila! That works. The spark is definitely not as strong as with the TT, but it keeps me happy in the meantime.

So, as FYI to others out there who might have had the pack go bad on them, it could just be the ballast resistor. From the research I've done, there's no easy way to test the ignitor in those things without a special tester. A coil is easily tested with a multimeter (can't find mine!). Don't throw 'em out until you've at least given them half a chance.

gsl-se addict

iTrader: (3)

That is great information. We just figured it was the ignitor, but maybe it has been just the ballast. It makes sense. As the coil pack gets hot, the resistor can no longer remove the heat needed. Eventually it gets to the point where it fails. Perhaps it is the main source of the heating as well (instead of the ignitor). The reason for heating is the same as the coil charge time is too long. One possibility is to just get some large power resistors and remote mount them for people that just what to do the simple TT.

Maybe people that have had failures can check the resistance of their ballast. It would be interesting to know how many are ballast failures. I will check into finding a good power resistor. Then maybe someone can try either the simple TT or the TT from the last batch and see if the coil pack heats up.

devitek

Since there is virtually no difference in performance with just the coil hooked up, I will likely be taking that off soon and seeing if I can set up the simple TT again. It's still possible that the ignitor is blown in there, but until I try I won't know. If you come up with a good resistor, let me know.

t_g_farrell

iTrader: (1)

Kent, I've got a simple TT built that I'm getting ready to mount after I bench test the circuit and verify that my J109 and 2G coil are good. I have an SA, my plan is to use a J109 mounted with the TT and 2G coil so I don't have to touch or use my existing J105's except to run some leads to the new ignition, that way I have an easy backup igntion should I see failure.

I was getting concerned about this heating up problem and did buy a large power resistor because you mentioned it in the simple thread. Can't remember the value on it but it was like maybe 10K or something. Anyway, I think you said to hook it up one the 12v power connection for the 2G coil to keep it cooler. Is that what your thinking here ?

If you can decide on a value and type of resister let me know with PM and I'll get it and try with it and without. Probably be about 2 weeks before I can get results back to the board, but let me know.