To spark or not?

[2seater]

I understand the knock thread had been detoured so I started a separate thread. I did a quick test with the two inductive lights I have, one is an Innova and the other an old Sears. In a quick test, the Sears only fires in the correct polarity position on the coil I tested, so it would seem that my statement was incorrect, at least sort of. The Innova also has a tach function, and I did not actually try the timing light itself, but just checked to see if the tach operated. It appears to operate in either direction, despite the polarity arrow. The only peculiarity is it reads double rpm in one direction, as it should, but normal rpm in the other? I certainly don't understand all of the details of how this all works?

The other test was to see what happens if a plug wire is disconnected, but the test is somewhat inconclusive. If I pull the wire at the coil pack, the other plug wire does continue to operate, however the open terminal arcs to a mounting screw, so the coil is still going to ground, so I would guess the circuit is still complete? It does kill only the disconnected cylinder, but I do not know if it would still be true if there were no path to/from ground like pulling the wire from the plug itself?

The results are somewhat different than what I have found before, so it may be the tight confines of the hookup itself, operator error, or the quality of the instruments themselves? It's more out of curiosity than a serious issue, but if anyone else would try the same test, I would be very interested in the results. I will look at it further when time permits and a cooler engine.

[Ronnie]

Hal, Do the same test but instead of pulling the plug wires off at the coil pull the wires off the spark plugs. Tie one wire up somewhere sit it can't arc to anything and then test the other wire for fire. I think you will find that plug will still fire a spark plug wire with the other one away from any ground.

[harry yarnell]

I am leery of pulling plug (ignition) wires as the coil discharge has to go somewhere, and that could be the electronics in the base of the coils.

Harbor Freight has a nifty test for spark; a 12" ignition cable with male and female ends that you put in series with the ignition (plug) wire. In the center of this wire is a clear window, if you will, that holds a small neon lamp. Pull one wire off the coil, plug it into th HF device, and plug the other end of the device onto the coil.

They're cheap; I bought six so I can see whose firing and who isn't with one hook-up.

[TexasJohn55]

Hello guys, I'm glad to see another thread, found it while browsing for where to start one, technical or where. To get interest and clearly display what the thread is about, is it possible to re-name the thread to "WASTED SPARK IGN SYSTEMS and INDUCTIVE TIMING LIGHTS" ? I just want to attract all the input we can get. Maybe a moderator can moved post #'s 36,37,39,40,43,44,45,47,48,49 and 50 from "Knock" to this thread? I sense there is a very good opportunity for ME to learn something here and maybe educate others as well on the matter. TexasJohn

[TexasJohn55]

Man that was fast, it is already done! Our moderator is on the ball! Thank you. TexasJohn

[TexasJohn55]

Equus Innova 3551 Timing light marked "DIS. Conventional" When connected to plug wire on '98 Olds Series II 3800, would not fire the strobe with pickup turned either way on any plug wire. It would try to fire strobe when I pulled companion wire and completed a circuit thru me and the timing light! Didn't enjoy that much! Let's hear from others on their make and model timing lights to see which ones actually work. TexasJohn

[Ronnie]

Work for what? There are no timing marks on the balancer of a 3800. Have you tried the timing light on another engine to make sure the light will work at all?

[TexasJohn55]

Never mind, don't want to hijack this thread too.

[2seater]

The one I have is an Equus. I too was a little concerned with where the arc might go also so I'm not doing that again. The DIS systems are so much more powerfull than the older style, no matter what the style. I will have to get a better handle on my test procedure since near the coil pack is pretty tight and may be picking up adjacent cylinders? It was not completely consistant, that's why I asked for more input. While the timing light really doesn't have any direct use for tuneups, if it works consistantly, it can be used to check for spark where chasing a problem. If it remains flaky in operation, then it would be worse than nothing at all since you would get false/misleading results. The HF spark tester is also a great idea, and very reliable, but the timing light doesn't require anything more than clipping it on? Different ways to skin the cat I guess.

It is possible, my memeory is hazy when it comes to the way the lights worked, or, I am thinking of the DIS system on my Ranger, which operates exactly the same. It is more difficult to get to, since it on the top rear of the engine and a 4x4 is higher to boot. I do remember for a fact, that the first time I changed plugs on the Ranger, I could not get matching plugs for one side of the engine at the FLAPS. The plugs were single platinum, but the platinum was on the center electrode on one side of the engine and on the "ground" wire on the other. I imagine the factory did that to save money but still get extended life, all due to the reverse polarity on one side of the coil. The recommended replacement is a double platinum. Strange but 100% true.

[wws944]

That 'waste spark' has to go somewhere. Better that it arced from the terminal to the bolt head than the alternative. Being that an arc was created within the coil between the windings to complete the circuit - weakening the insulation between them in the process. Good way to lose a coil - though I have to believe the coils are designed to be robust in when faced with a failed plug or wire. At least for a short time...

[Ronnie]

That 'waste spark' has to go somewhere. Better that it arced from the terminal to the bolt head than the alternative. Being that an arc was created within the coil between the windings to complete the circuit - weakening the insulation between them in the process. Good way to lose a coil - though I have to believe the coils are designed to be robust in when faced with a failed plug or wire. At least for a short time...

The following is just for the sake of discussion, which I think is the reason this thread was created. Not intended to be argumenative...

I would agree that it might not be good for the secondary circuit of the coil to not have a path to ground. Probably more stress would be on the coil and ICM components and possibly more heat would be generated within the coil.

However, I see no reason to think that the waste spark must go somewhere. A properly insulated spark plug wire with one end attached to the terminal of the coil and the other end of the wire not being near a ground should be sufficient to prevent an arc.

Nor do I agree that there is an arc created within the coil windings to complete a circuit. There is a potential (energy) generated in the secondary circuit of the coil by the magnetic field that is created by the rise and fall of electricity in the primary circuit of the coil. There is not an electrical connection between the primary and secondary circuits that must go to ground as far as I know. They are two separate windings inside the coil. No arc is created until the high voltage potential in the secondary circuit of the coil comes near enough to a ground that it can jump the air gap.

Just my $.02 and as always there is a possibility that I am completely wrong.

[wws944]

It is pretty basic. In an older non-waste spark system, one side of the secondary is tied to one side of the primary. In a waste spark system, there is no such connection. However when you pull one plug wire off, there is enough induced voltage that the circuit tries to complete itself - one way or another. In 2seaters case, he reported a spark between the open terminal and the mounting screw! But it could also happen within the coil itself - essentially converting itself to a non-waste spark system on that coil. Obviously this is not good for whatever insulates the wires within the coil.

Personally, I would rather sit in the drivers seat, select injectors via diagnostic display, and count the investments in my portfolio.

[wws944]

BTW, one simple test whether new plug wires are needed or not: At night, start the engine and open the hood. If you see a 'light show' from the plug wires, they need to be replaced.

[2seater]

Yes, I started this thread to get some input on the quirks to be watched for with our ignition system. Generally reliable, powerful and the faults that may occur are fairly well documented. This all started as a related issue to checking on the rod knock test. Strobe lights can also be used to watch moving parts to see any anomolies that defy static testing, although a variable frequency strobe might be better for that. I would guess that the adjustable advance type light, such as one I have, can move the synch. with moving parts too? That's just random thinking on the subject. The real point was to ask for input on what sort of signal was available from an inductive pickup, and that's seems to be inconsistant, so my inquiring mind wonders why? I think I understand the basic theory, but certainly not the details. Since it is a sort of floating ground, maybe there is a lower amplitude reflection wave bouncing around in there too? I just don't know. I think I remember either lighted plug wires or some sort of piggyback that flashed (neons?) in response to the plug firing which was fun to watch on a running engine but I would imagine a modern system would blow right through them. I digress.

[Ronnie]

I just went back and read the entire thread "knocks" and this one. The takeaway for me is I need to stop offering old school tests, such as pulling spark plug wires to determine which cylinder is causing the knocking sound, unless it is specifically asked for. It's rarely appreciated and too many people on this forum have nothing better to do than try to find fault with it.

[padgett]

It is not so much "finding fault" as recognisiong that some tests are "old school" that worked well with "points, coil, and distributer" systems but may overstress higher power transitor units particularly in the secondary ignition where voltages can exceed 60,000v. ELI the ICE man is very much alive and sudden opens can cause large surges and spikes.

Just as we need to be carefull about jump starting now, we also need to use care in some of our testing. On another forum I am heloping with a 2014 model that appears to have overstressed many components (dash, "entertainment center", PCM, ABS) with one loose ground & the factory/dealer is treating each component as it fails (four so far some that leave the car dead in the middle of the road.) rather than admitting the whole electrinic system needs to be replaced.

[2seater]

I just went back and read the entire thread "knocks" and this one. The takeaway for me is I need to stop offering old school tests, such as pulling spark plug wires to determine which cylinder is causing the knocking sound, unless it is specifically asked for. It's rarely appreciated and too many people on this forum have nothing better to do than try to find fault with it.

Not quite sure where this is directed, but I brought up what I thought was a valid question due to the operation of this ignition system. I did mention in the first post of this thread, that removing the one wire from the coil, which seems most convenient to me, does indeed just deactivate only the one cylinder. Perhaps not a direct retraction, but in support of the spark disconnect being a valid test. The use of the diagnostics for injector deactivation as an alternative is available on this vehicle, so it seemed logical to suggest? I too have offered old school tests, such as a vacuum gauge or compression test, but generally it does indeed fall by the wayside or at least far down the list of things tried.

[Machiner 55]

For those of us (meaning me) who don't know ELI, see the following.

John F.

PS.

I want to thank all the posters who responded to the original "Knock" post with suggestions and helpful advice.

Edited May 16, 2013 by Machiner 55 (see edit history)

[2seater]

Hmmm, now my head hurts I think I follow the basic premise, but will take some time to digest. Of course that causes me to ask if this has any effect on the way our conventional timing lights see the signal? These ignitions are quite powerful, and I know "old school" concerns about separation and routing of spark plug cables to prevent crossfire or induced spark in parallel cables would seem just as valid today, or maybe more? I would guess it isn't as big an issue with a V6 that fires in order on one side of the engine and then the other, not like the problem child V8. The front cable routing through the quasi insulator/loom on the valve cover doesn't leave much choice unless removed however the rear cables are relegated to being shoved through any room available behind or under the alternator. Maybe induced current in a parallel cable, while not powerful enough to fire a plug is enough for the timing light to be erratic? Hmm, maybe I will get an old cable or two and connect them outside of the normal routing to see if things clear up.

[wws944]

It isn't just just the fact that transistors are used for switching now. The topology of how the coil is wired is different. Here is old-school. Note that the primary and secondary windings are tied together on one side:

Waste spark systems do not not have that connection:

As far as timing lights go, a few years ago, I tried using one on my now-gone '90 Regal. (It always had a random 'miss' when idling, and I never fully figured out what the problem was.) It had a waste spark DIS system almost identical to the Reatta. The light was definitely erratic. But the 'miss' was clearly visible when it happened.

[harry yarnell]

Again, I bring up the subject of removing a plug wire, causing an open circuit in the secondary. One plug will attempt to fire only thru the engine block, then to where? Internal of the coil? Ignition electronics?

[Ronnie]

Not quite sure where this is directed, but I brought up what I thought was a valid question due to the operation of this ignition system. I did mention in the first post of this thread, that removing the one wire from the coil, which seems most convenient to me, does indeed just deactivate only the one cylinder. Perhaps not a direct retraction, but in support of the spark disconnect being a valid test. The use of the diagnostics for injector deactivation as an alternative is available on this vehicle, so it seemed logical to suggest? I too have offered old school tests, such as a vacuum gauge or compression test, but generally it does indeed fall by the wayside or at least far down the list of things tried.

My comments weren't directed at any one person. My comments were more about how this forum has evolved to the point where offering free help is no longer satisfactory. Now if you offer help you must be prepared to justify the help you offer and you must be prepared to defend your position from the scrutiny of those people who normally take their cars to "their guy" to get it fixed. The same people who rarely offer any help but are quick to search the Internet for find something that they think contradicts what you have said. Then armed with that new found information they feel like experts and they give their opinion about why the help that has been offered should be ignored.

In the case I offered help to find which cylinder produced the knock. I knew the test would work. I have used it for years. It was acknowledged by the original poster that the test worked. Another poster said the same test had worked well for him many times but he was ignored. From there it turned into a bunch of woulda coulda shoulda BS that was really just a waste of time and accomplished nothing.

I expect my days are probably numbered on this forum for making statements like this but sometimes the truth needs to be told.

Hal, I completely understand the question that you asked about the ignition system and operation of a timing light with the 3800 ignition system. I can't explain the anomalies that you found when trying to use the induction light. I have one of the old lights that connects to the terminal on the coil and it works perfectly with the 3800 system. I think the question you posed is something that is worth discussing but if you will notice, this thread is going back to discussing why spark plug wires should not be removed. I have worked on a lot of cars in my life but I have never worked on one where the ignition system was destroyed by a spark plug wire falling off. OK guys, start a Google search for "spark plug wire destroys ignition" and I'm sure you will come up with something.

[2seater]

It isn't just just the fact that transistors are used for switching now. The topology of how the coil is wired is different. Here is old-school. Note that the primary and secondary windings are tied together on one side:

Waste spark systems do not not have that connection:

As far as timing lights go, a few years ago, I tried using one on my now-gone '90 Regal. (It always had a random 'miss' when idling, and I never fully figured out what the problem was.) It had a waste spark DIS system almost identical to the Reatta. The light was definitely erratic. But the 'miss' was clearly visible when it happened.

Interesting. I imagine it is a simplified diagram, but I don't see where polarity is an issue? I'm sure there is more going on here, and it looks like there isn't anything that actually completely drains the spark cables, so what happens to the excess potential energy?

[2seater]

Hal, I completely understand the question that you asked about the ignition system and operation of a timing light with the 3800 ignition system. I can't explain the anomalies that you found when trying to use the induction light. I have one of the old lights that connects to the terminal on the coil and it works perfectly with the 3800 system.

I also have a direct connect Penske (Sears) timing light that I was going to try also, but that exposed spring used as a connector sometimes caused an arc where clearances were small. Shouldn't be an issue in the relatively large space at the coil pack, as long as the path to the plug has less resistance.

I know I have a thick skull, but the picture is slowly getting clearer. I would guess that the quality, sensitivity and filtering of the inductive light would affect the result? It isn't needed on these systems, and it appears any secondary use is problematic, so maybe it goes back to the toolbox?

[Ronnie]

Below is a photo of the one I use. It is made by Sun. It is at least 20 years old and still works. As you can see it has a pretty good insulator. I guess it would arc somewhere if a spark plug wire wasn't attached to it on the newer higher voltage systems but it hasn't been a problem that I can remember. I've used the induction lights that clip on to the wire a lot at work but never felt a need to invest in one for home use as long as this old Sun is still working.

[TexasJohn55]

My intention was to stay off this thread, just sit back and learn. Reference post 4 and 6. My primary interest in this thread was to identify which inductive timing lights, by make and model, would reliably work on DIS/Wasted Spark ignition systems. The point was not that I could not time my 3800 with it, Oldsmobile is not the only car on the market. Visit the rx7 site and see the trouble they are having with rotary timing. A reliable inductive timing light would be useful for other diagnostics besides timing. It is very easy to clip on a wire and determine if that cylinder is firing, a bad wire or plug on a conventional system won't trigger the strobe, does that work for DIS as well? Which timing lights are reliable? There doesn't seem to be much interest in that. I want information that I can apply to troubleshooting without all the theory and without exhorbitant cost. TexasJohn

[DAVES89]

I just use an old hair dryer and make believe I'm a mechanic...

[Ronnie]

I just use an old hair dryer and make believe I'm a mechanic...

We have a lot in common Dave. I use my old timing light and pretend I'm a hair stylist. Don't tell my wife any different. I've had her fooled for years and it saves me a ton of money on getting her hair done. :p

[padgett]

OK try this: the coils in an alternator act as a very large inductor (L) and a battery as an equally large capacitor ©. WHen at a high rate of charge, the alternator goes to 14ish volts and starts building current to try to make the battery match. If the battery is ded, it can take a lot of current: all the alternator can push (and a CS-144 can push A Lot).

Now if somone suddenly disconnects the charging battery, the current has nowhere to go but the field in the alternator is still at max so what happens is ELI kicks back and the voltage goes through the roof. If you are lucky it just fries the regulator but if it holds together for a few milliseconds, all electronics that is turned on gets spiked.

Alternately at 100A & 12v you are pushing 1200 watts. If the current goes to zilch and the watts stay the same (field will collapse in about 50 milliseconds but until then things get interesting) the voltage will take up the slack. The scientific term is "hysteresis".

Back in the day of 37 Amp alternators that could not keep the lights bright at idle and big discrete devices, all that got fried was an occasional radio but with a 120 or 140 Amp...

[Machiner 55]

The scientific term is "hysteresis".

My wife had that done.

Hasn't been the same since.

John F.

[TexasJohn55]

[ Which timing lights are reliable? There doesn't seem to be much interest in that. I want information that I can apply to troubleshooting without all the theory and without exhorbitant cost. TexasJohn

[2seater]

Texas, I do believe you have narrowd the focus to what tool will work, which does get to the nub of the issue. I will admit I do not understand what some already know intimately, and I find the explanations very interesting. I always feel my day has not been wasted if I learn something. I must take off for a wedding out of state, so I won't have time to investigate further at this time, but the visible spark indicators as suggested would be reliable and also the direct connect timing lights. I do like the tach function on one of my inductive lights and that is probably the easiest indicator that you are getting all of the sparks that should be occuring. A random missing spark may be harder to detect with a direct connection if not observed closely, but reliability should be good. I think you are correct about the title of the thread, it would be better if related to Inductive lights with DIS systems. I can't fix that. Can you Padgett?

[padgett]

No, I would need to create a new thread and move all posts there. Since all is related to spark, I do not see an issue.

I will need to try my Sears variable timing light but since you cannot time a 3800 that way, have not bothered.

[TexasJohn55]

The point was not that I could not time my 3800 with it, Oldsmobile is not the only car on the market. Visit the rx7 site and see the trouble they are having with rotary timing. A reliable inductive timing light would be useful for other diagnostics besides timing. It is very easy to clip on a wire and determine if that cylinder is firing, a bad wire or plug on a conventional system won't trigger the strobe, does that work for DIS as well? Which timing lights are reliable? There doesn't seem to be much interest in that. I want information that I can apply to troubleshooting without all the theory and without exhorbitant cost. TexasJohn

Again

[Guest Mc_Reatta]

Any timing light that is functioning properly will work on our DIS wasted spark ignition. The advantage of the inductive one is that it can be attached anywhere along a wire with no need to disconnect any wire and insert inline. They simple sense the spark surging in the line (directly or inductively) and trigger the strobe light.

If you already have a light, just hook it up per instructions and try it out. I still use mine from time to time to see if there is a misfire which shows as a dropout in the normally regular flashing pattern on a wire.

If you don't have a light it probably isn't worth getting one as a HF inline spark detector will show the same thing and is inexpensive.

If your light has a RPM or Dwell meter on it, the RPMs will not show correctly since the wasted spark will be counted as well as the true spark so the meter will see 2x sparks per revolution which will confuse it. Also, most meters were set up for 4 or 8 cyl engines so a 6 cyl RPM may have had to interpolated even back in the day.

Dwell is meaningless in a DIS as there are no mechanical points involved. Dwell is a function of the triggering electronics in the ICM.

[TexasJohn55]

Any timing light that is functioning properly will work on our DIS wasted spark ignition. The advantage of the inductive one is that it can be attached anywhere along a wire with no need to disconnect any wire and insert inline. They simple sense the spark surging in the line (directly or inductively) and trigger the strobe light.

If you already have a light, just hook it up per instructions and try it out. I still use mine from time to time to see if there is a misfire which shows as a dropout in the normally regular flashing pattern on a wire.

If you don't have a light it probably isn't worth getting one as a HF inline spark detector will show the same thing and is inexpensive.

If your light has a RPM or Dwell meter on it, the RPMs will not show correctly since the wasted spark will be counted as well as the true spark so the meter will see 2x sparks per revolution which will confuse it. Also, most meters were set up for 4 or 8 cyl engines so a 6 cyl RPM may have had to interpolated even back in the day.

Dwell is meaningless in a DIS as there are no mechanical points involved. Dwell is a function of the triggering electronics in the ICM.

Maybe you haven't read all the posts on this thread and "knock" thread. I do have a functional inductive light but it wil NOT trigger on my '98 Olds. I would like to know which lights have proven to be reliable on this system, so tell me which light you have that is reliable on DIS/Wasted spark systems. I need to know brand and model specifics. TexasJohn

YEAH RIGHT! I THOUGHT I HAD A FUNCTIONAL LIGHT! Don't assume the veracity of everything you are told. My son said it worked the last time he used it, but the inductive pickup must have hit the floor since then, the horseshoe inside it was broken and didn't work when I tried to use it.

Edited June 4, 2013 by TexasJohn55 (see edit history)

[Guest Mc_Reatta]

I have a Heath inductive timing light I built from a Heath Kit so many years ago I can't remember. Only time I have a problem is when I can't get the clamp to seal completely around a wire to complete the loop so it will fire. I sometimes have to use some rubber bands to keep it closed as latch has gotten sloppy with age. The ignition on the 98 Olds is the same as the Reatta (ICM Delco upgrade, Coils, wires) as I swap parts between the Reatta and my 99 Olds whenever. Plugs are different on the Olds since I think they can be longer than on the Reatta so more types are available for the Olds.

If your light works on the Reatta but not the Olds, I'd be looking at the wires. They either are keeping the clamp from closing completely or they have some extra shielding that is keeping the coil from seeing enough signal to trigger the light circuit. If it doesn't work on either, then I question your statement that your light is functioning correctly.

But as I said, I wouldn't recommenced buying another timing light over some HF or other spark detectors at this point if it wasn't working.

[TexasJohn55]

Mc_Reatta, Thank you kindly for the reply. My son said it worked fine on his conventional 460 engine the last time he tried, but it will not fire the strobe on my '88 or '98 Olds 3800 cars. I don't have a car available at the moment to test it on conventional system so I cannot be sure except to say when I had it connected on my '98, it only strobed when I lifted the companion wire from the coil and it arced thru me and out the switch on the timing light on my other hand! Otherwise would not fire strobe. I will get back to you after more testing on conventional system. TexasJohn

[Guest Mc_Reatta]

The car's ignition should not even know there is an inductive pickup installed on a wire. Without knowing exactly what's going on with yours, I'm thinking there may be stray voltage field in your pickup coil that is masking the signal that the standard spark creates, and only when the entire spark is forced out one wire does it trigger.

May just have to loan it out to folks who's hearts need some pacemaker defibrillation action.

[Machiner 55]

TJ55,

Here's the timing light that I bought in August of 1992 for $69.99.

I just went out to the garage and hooked it up to my wife's 1998 Olds 88. It worked perfectly no matter which way I connected the clamp to the plug wire.

There is no mention of polarity or orientation, in the manual, regarding the clamp attachment nor is there an arrow label denoting direction on the clamp. I had another light, that I believe is long gone now, that did have an arrow lable on the clamp.

Edited May 22, 2013 by Machiner 55 (see edit history)