[franky 455]

Ok guys "" we have ignition " well we have a spark anyway. Here is the latest, I bought a new loom with the capacitor, threw it in and - nothing. I now have everything replaceable, apart from bushes, brand new.
I left it until today, as Geoff volunteered to check it out. He started by testing it out of the car,on the bench where we got a great spark, threw it back in and - no spark.
He noticed a larger gap between the points of the reluctor & the pick up coil, compared to another HEI dizzy I have borrowed.
I cleaned up the borrowed dizzy & installed all the new parts apart from the new, after market, pick up coil, threw it in the car and - spark.
She fired up but was sick, at this time the battery was getting flat, so we called it a day & put everything on charge, for the next time I get a chance.
What we discovered was that turning the dizzy by hand slowly ( cranking speed ) it would not spark, yet quicker, it would. With the other dizzy you could turn it slowly & it would spark.
I noticed I didn`t get that notchy feel as you rotate the shaft by hand, that I got prior to replaceing the pick up coil. What do you think? heard of that one before?
Take it easy, Frank.

[Sun Tuned]

Pickup coil was out of alignment. All 8 teeth should freely rotate inside the outer teeth of the pickup coil with out touching ANYTHING. Any touching equates to a misfire. Bushing wear figures in on this also.

Might also clean the teeth on the reluctor if you got it apart with a small handheld wire brush. Don't round off the teeth of the reluctor, just clean the metal so you have a clean surface for good magnetism between the 2. Check that airgap!

[Sun Tuned]

I believe I owe you a quick troubleshoot.

Can find this in most of the better shop manuals. many may not have that access though and have the access to this board.

First get some simple tools, won't need much...

1. 12v test light
2.simple volt/ohm meter
3.spark tester
Now this can be bought at the parts house or you can make one in a small amount of time. All it is , is a spark plug that has the ground electrode cut off so the spark has to jump approx .125 of an inch. it also has an alligator clip brazed to the hex of the plug shell. Cost: about 5.00 in the states or you can make one just as good out of an old spark plug for lots less.

Now let's get to work...

First Take the volt/ohm meter and verify the battery voltage across the bat terminals of the battery.

Then disconnect the "BAT" terminal on the dist cap (which is the 12v lead to the dist cap itself) and turn ign switch on and read voltage. Neg lead of meter to good ground and pos lead to the 12v wire terminal you just disconnected. Should be same as battery voltage or maybe a .1 volt less.

Reconnect the 12v wire to the cap and remove a plug wire. Connect the spark tester(alligator clipped plug)to the removed wire and put the clip on a good engine ground(bolt,alt case, etc.

Crank engine and if you get spark, look somewhere else as the HEI is good.

If not ... then here we go.

Remove coil cover on top of cap.

+ lead of voltmeter to "BAT" terminal
- lead to good ground
crank engine... less than 7 volts = problem in wiring from ign switch.

If more than 7 volts move the + lead to the "TACH" terminal of coil and turn ignition to "on" position. If reading now is less than 1 volt, then the ign coil is likely toast. If reading is 1-9 volts then the module is likely toast.If more than 10 volts, then attach spark tester to the carbon brush under the cap

(will need to lift cap off of housing and turn upside down for this, leave the little cap harness connected for all tests)

Spark tester will need a jumper wire from its shell to ground for this next test.

Crank the engine and spark should be jumping all over the tester. If that happens then look at cap for crack,water, mice, moth balls, old tools, small animals, etc.

If there is still no spark, then pull the pickup coil leads (green/white) from the module.

connect the - lead of voltmeter to good ground.
connect the + lead to "TACH" terminal.
Connect the 12v test light alligator clip to the "POS" battery post.
Turn ign switch to on position.
Watch the voltmeter as the test light is touched to the "G" terminal of the module FOR NO LONGER THAN 5 SECONDS AT A TIME, or you'll maybe smoke the module and be buying another.
What this does is put a trigger voltage to the module and causes the little transistor inside the module to close the coil primary ground circuit. Now when you remove the test light the voltage goes away and the transistor lets go and the coil primary collapses.

At this point the voltage reading on the meter should drop. And there should be a spark from the spark tester still connected to the carbon brush.

If voltage does not drop then look and be sure the module is properly grounded and all grounding connections are clean.

If voltage did drop and there was spark across tester, and you were tring to originally diagnose a "no spark/no start" condition....then replace the pickup coil. Why? because now you got spark when your supposed to have it, except the pickup coil is the only thing NOT still connected. Removing voltage from the module caused the transistor iside it to turn on/off. If you got spark at the tester then you know that that was happening.

You can also test the resistance of the pickup coil (green/white) wires and read the resistance between the 2. GM specs call for 500-1500 ohms.... I say 760-860 is good and anything else may work, but usually not in my experience, vey well.

If you got no spark when the test light was removed, then the module is likely bad, that is if you did the test right. It could also be because the ign coil ground was dirty/faulty etc. It is also possible that the ign coil itself is bad, so GM recommends a module testing unit to test the module seperately, to diffrentiate between the 2.

As confusing as this all may seem it is fairly starightforward.


Now let's take a look and see what we should do that's not really in the shop manual that happens in the real world.

Got one that has no spark and no start...

1.verify battery voltage.
2.check voltage at lead wire to cap with
key in "on" pos and in "cranking" pos.
Should be within batt voltage with key
on and around ideally 10 while cranking.
3.Remove the coil cover
4.Check primary resistance of ign coil
Red/White or Red/Yellow wires with plug
cap connector removed.
Good coil will read approx .5 to .9 of 1 ohm
Bad coil will be .2 or less or higher than
say 1.5 ohms.
5.Read secondary resistance of coil.
2 ways to do this with coil out of cap
and with it in the cap. Difference is ease
of testing and final reading due to carbon
brush.
Ohmmeter lead red to "ground" terminal
ohmeter lead black to carbon brush under cap
resistance will be 6000-30000ohms.

I like to read that with the coil out of
the cap, in that case test the round metal
disc at bottom of coil and the black ground
wire coming out of the coil epoxy.

Reading should be lower and usually in the
8000-9000 ohm range.
Reason it's lower is your not taking into
account the resistance of the carbon brush
itself. Most brushes read about the same
but do realize that hey can differ to some
extent.

If you get a good reading on the primary and
secondary then likely the coil is good and
at least you know it's not shorted and can
go on testing. I like to take the time to do
this before hanging the internals all over
the engine compartment. Usually if you find a
odd reading here you can save the detailed
testing as you will only find you already
have found the problem earlier.
6. Check the resistance of the pickup coil.
7. Check the grounding of the pickup coil
leads in relation to the housing. Reading
should be infinite here on both.
8. Then go into detailed testing after the
previous 7 steps have been looked at.
Might save you some time.

Hope that helps.

Got some distributors that have been here a long,long time. Can't get in touch with the owners for some reason... e-mail not working right or no answer at the phone number they listed and a couple have no return address, or phone number either. Am still trying to contact these individuals. Just to let everybody know.

See ya!

[Malky]

Fantastic info, Sun Tuned. I have never seen this written down anywhere else.

[franky 455]

Sun Tuned thanks for the trouble shoot, it is something I will print & keep in a safe place, as I am sure everyone reading it & has an HEI will. I checked the air gap we spoke of & it's around 18 thou (very hard to measure), do you think that is excessive? please read my last post & how we found the problem, it is a brand new pick up coil, Thanks again.
Take it easy, Frank.

[Sun Tuned]

Well,
I gotta say here in the last 3 years especially, the quality of these pickup coils is suspect at best. I have had more problems with these damn things lately than ever.

Brand makes no difference, it used to. Lately the old standbys are worse than the cheap stuff. Some will unexpectedly go awol on you, had 3 do that. Lasted about 2 weeks and then poof no working those were Standard coils. Then there was a friend of mine who puts together way more of these things than I do, who got a bad batch from Delco that were wrong polarity. Most lately will just be out of alignment.

This stuff isn't the newest, current, most technologically mind boggling part on a car anymore, so you gotta figure they got a bunch of .50 cent an hour labor slapping this stuff together thesedays.

With that said... I absolutely hate and have had little luck with anything that,that "Zoned out" place sells electrically. However, they do have one thing I will buy that does work for now at least. That is their Wells brand pickup coils.

I know what some of you are saying, and I know, I know. Take a digital ohmmeter with you, test what they bring you and they should all read right at 846-855 ohms. Every one. Make sure they aren't physically cracked or damaged and measure them and go home with it if it passes.

I have not been able to install 1 pickup coil yet in the last year that dropped right in. Not 1. I don't even try anymore, I automatically re-align them all before installation. Why??? Well they won't be right if I don't. See, if any of the teeth come in contact with the pickup coil you got a problem. Most of these pickup coils are real close but as far as I'm concerned "close" only counts in Atomic bombs and hand grenades. So to be right they gotta be fixed. Not hard to do but tedious if you don't got the dowel tool to do it with. If you don't, you turn the reluctor till all 8 line up with all 8 on the coil and look at them. Magic marker the ones that are real close to touching and you'll see that you probably end up with 2 or 3 that have marks showing they need fixing. loosen the 3 screws that hold the thing together and favor the side that had the tightest clearance and make that side have more clearance by pushing the ring one way or the other. Retighten the screws and test fit it all again. Very time consuming to do but most all need it done.Why don't they come better aligned? Costs more money to make sure of all that nonsense is done right they say. Fixed 2 that had that exact same problem and several big name shops here in town worked on these guys cars and to no avail. Cars still had a dead miss in them. Carb guys going banannas trying to fix a prob that never existed in the carb to begin with cause thats where everyone said the prob had to be.

And yes, you can cheat on this. You can very lightly file the tips of the reluctor to gain clearance, BUT! BUT! BUT! I'll say it again, BUT, YOU WILL DECREASE THE SIGNAL STRENGTH OF THE DEAL BY DOING THIS, IF NOT DONE REAL CAREFULLY! It can be done, and successfully but I do not recommend doing it. I would rather see you properly align the pickup coil first.

So far the Wells pickup coils have been the most stable from coil to coil and the closest to being in alignment, as of today..SEPT 6, 2004. That way you don't have to go jacking with stuff you really don't want to or have the tools to work on anyway.

.018 sounds awful wide to one side to me.

[Malky]

Franky, if it won't spark at low speed and you don't feel the "notchiness" when turning, could the ring magnet under the stationary teeth be weak?

[franky 455]

OK Sun Tuned the search now begins for me, for the Wells pick up coil, as that .018 is all round, not just one side, no rush as I have the other dizzy in for now.
Malky, to answer your question, yes there is every chance that the magnet is weak, & is what I suspect from this cheap & nasty pick up coil, but how do you measure its strength? This is why I am going to look for a better one. Thanks everyone & I will let you know how it goes. Local car show on Sunday & I want to go in it.

[buwalda]

I'm the 'Geoff' that Frank referred to. The aftermarket p/up coil had a noticably bigger air gap between the reluctor teeth & pole piece than did the stock piece. My guess is the gap is upwards of 0.015" & could be as large as 0.025"; hard to measure without brass feeler gauges. This aftermarket p/up coil produced a great spark on the bench because spinning the dist shaft by hand generateed a higher voltage than when cranking more slowly in the car; in the car, the output from this pick up was too low. I compared both p/ups on the bench by spinning the dist shafts by hand & measuring the output at the p/up wires. The stock p/up generated about 100 mv & the aftermarket one generated only 30-40 mv; both measured around 770-780 ohms. I think Frank also has a couple of other problems that have aggravated this problem. His battery voltage was low when we started, about 12.38v, usually a sign that a battery is past it's peak; also, I think his starter may need a rebuild because it seemed to me to crank slow, even with a booster connected. At the end, we had it firing, but not starting, & I believe he now has a Holleyitis problem. The Holley has no choke, but fires when you pump the pedal; so it appears the engine uses up the pump shot to fire, but there is no idle or main circuit to maintain running. We'll get there.

[buwalda]

Should have added that we had a wire direct from the batt [+] terminal to the [+] terminal on the HEI, so the HEI was definitely getting full battery voltage.

[franky 455]

Just to put closure to this topic & thank eveyone that contributed, My Firebird is flying once again & is very happy with its new spark.
It seems the problem was the pick up coil, even though it was new. The gap from the reluctor on the shaft, to the points of the pick up coil were to large all round & could not be adjusted.
Hope this helps.
Frank.

[wk wood]

I recently discovered this site and just found this discussion. Just last week I had basically the same trouble with an HEI unit that I cleaned up, put some new parts in and put in my Grand Am. I checked everything and was real frustrated when it would'nt start 90% of the time. It turned out to be my pickup coil was the problem. I learned the hard way that you are not supposed to take it appart. I did this when I cleaned up the distributor. I bought a new Wells pick up coil at Auto Zone and now it starts right up. It is good to know that they can be adjusted with care.

[Sun Tuned]

Glad you got it fixed Franky, and thanks for letting us know what it was. That just illustrates... new doesn't always mean good.