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87 Chevy Sprint Turbo; what a blast
Topic Started: Aug 31 2011, 09:22 PM (20,434 Views)
Jittney
Anchorage 92 XFi

iBLKBRY
Jan 28 2012, 03:23 AM
I concur. Have you accomplished this?
Yes, we tried the jumpers, fused and non fused....to no avail.

The code 41 (ignition coil) .....still needs to be resolved.
The original coil tested 1.6 by me....then 1.9 by my son.....and then occasionally OL....then a permanent OL.
So another coil was necessary.
And with it, we still get code 41.
Whether the rockauto coil will work...I don't know.
I'll leave it in there and continue with testing.
Time for mwebb's suggestion of a colored diagram




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Memphis metro


When all the nut cutting is done, I believe it will end up getting a pickup coil to repair it, but thats just me.

Code 41 is not a ignition coil code. Code 41 is ignition signal to ecm is interrupted. This signal comes from the pickup coil, not from the ignition coil itself. Either way, the lady will get it fixed. She is persistent.
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Jittney
Anchorage 92 XFi

blue rhino
Jan 28 2012, 11:07 AM
Code 41 is not a ignition coil code. Code 41 is ignition signal to ecm is interrupted. This signal comes from the pickup coil, not from the ignition coil itself.
@ Blue Rhino, it does not look like we are reading the same material.
I have the 1987 Sprint FSM.
And now the 1987 Sprint Turbo Supplement from t3ragtop's Post #41.
http://www3.telus.net/public/skunka/mk1.pdf
Page 33 contains the diagnostic codes.
Code 41 reads. 41 - ignition signal - no signal from ignition coil for 2 seconds with engine starter switch turned on.
(perhaps your definition of 41 works, too....I will look at signal to ECM circuit)
Back to my Code 41 suggestion.....
Check ignition coil using pdf from post #41.
The pdf is for 1987 Chevy Sprint (does not mention turbo in the pdf)
Old ignition coil was toast.
Better coil....same Code 41...back at square one.
OK....back to studying.
Temp -20.



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Memphis metro


I believe the turbo was probably introduced mid year of 87 and the repair information was not included in the 87 fsm but was included in the 88 model manual. (thus the reason I originally thought you had a 88 model) I have no evidence of it but notice with my information under a 87 model there is no turbo model listed. I am a little confused about your information as well. In the last post you say you downloaded the 1987 Sprint Turbo Supplement, then further down you say turbo not listed in the pdf. Maybe he can find you a 88 Sprint Turbo supplement or online manual that would show you the turbo model information. I gather in neither of your information sources do you see the turbo model information?
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Jittney
Anchorage 92 XFi

The Turbo Supplement came from t3ragtop's link.
the pdf comes from the arrc.ebscohost.com (GMF members can access it)
See GMF > Garage > Repair Manuals/Wiring Diagrams > Online Repair Info > online repair manuals
It requires a password that's in the thread.
Or, in my case, we have open access to it in Alaska, and I can go directly to arrc.ebschost.com
From there....I chose the Auto Repair Reference Center >1987 > Chevrolet > Sprint > FI > Select > Repair Information > Engine Electrical > Distributor Ignition System > Ignition Coil > Ignition Coil Testing > view the pdf or download it.
I put it on my webspace so that I could link it to the forum....since many people cannot read links off the ARRC site unless logged into it.
btw, there is also a choice for 'Distributorless Ignition System' that has no pdf, but does have the same specs and testing as the Distributor Ignition System.....just no pictures. It reads, in part....

A Measure the resistance between the positive and negative terminals. Resistance should be 1.08–1.32 ohms electronic ignition with knock control and 1.33–1.55 ohms for all others.
B. Measure the resistance between the positive/negative terminals and the coil high tension wire terminal. Resistance should be 11.6–15.8 kilo-ohms.
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Jittney
Anchorage 92 XFi

Update on testing.
My oldest son dropped by...and tested the old coil...and was able to get a reading again 1.7 Ohms. :dunno
Maybe something is loose inside?
Put it in the car...and we get a spark.
Compare the new coil to the old coil:

Old coil testing (it can still produce a spark at the end of starting crank)
1. Across the terminals 1.7 k-ohms
2. High tension wire terminal to positive or negative is 15.35 k-ohms (spec 12-16)
New coil (absolutely no spark)
1. Across the terminals 1.7 k-ohms
2. High tension wire terminal to positive or negative is 6.75 k-ohms (spec 12-16)

The high tension terminal test is the more important reading?

Still, when the car is off...turned just to on..without trying to start, code is still - 12 - all clear.
Only when trying to start it, does it switch to 41 - ignition signal
What does it mean: "no signal from ignition coil for 2 seconds with engine starter switch turned on"?

So we tested what seemed logical...and found:
Voltage to the ignition coil.
Continuity from the ignition coil to the ignition switch (B/W)
Continuity from the ignition coil to the computer (W)
Not sure about testing continuity from the computer to the ignition coil.
The only other wire off the coil is Br/W....and it goes to the radio suppressor (in the wiring digram)
We also don't understand why the ignition coil consistently gives off a spark at the end of the start attempt.
Going on the theory that there might be a sweet spot in the ignition switch, we tried starting with the key and then slowly letting off on the key....to see if we could keep the spark going.
Instead, Hans saw a puff of smoke from the ignition switch on the lefthand side.
When we tried it again, I didn't see a puff of smoke, but saw the yellow light inside.
I added a star to this picture...to show....at the ends of the points is a segmented white circle.
In the spaces between the white (what is now dark) it lit up.
Posted Image

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Memphis metro


What kind of readings did you get on the pickup coil? What are the specs on it according to your information?
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Jittney
Anchorage 92 XFi

Specs for pickup coil are 900-1100 ohms.
With distributor lead wire disconnected at coupler, resistance from white to yellow is 758 ohms.
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Memphis metro


Didnt you say you purchased a pickup coil? If so test the new one and see what it reads.

My information shows the same specs for a 88 pickup coil and says if not within that range to replace it. That many ohms out is a good amount.
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Jittney
Anchorage 92 XFi

We just pulled the distributor.
We'll be changing out the pickup coil on it.

Below: backside of ignition switch...see the slot at 8 o'clock where the key tumblers are.
Even with the electronics out, the key doesn't go in all the way and turn easily.
So, this mechanical part has issues.
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Below: the ignition switch... this is the part that was arcing
We'll try to take the white plastic off without wrecking it.
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Below: Distributor getting a cleanup before replacing the pickup coil.
Posted Image
Edited by Jittney, Jan 28 2012, 06:55 PM.
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Jittney
Anchorage 92 XFi

Pulled the steering column.
Got the mechanical tumbler/key side working.
Don't have to pull it out an eighth of an inch anymore.
Posted Image
Pulled apart the ignition switch...pretty dirty.
Will clean it up with Qtips and brake cleaner.....and use a dollar bill on the contacts.
Not sure how it goes together, as it just flew apart. :-/
Posted ImagePosted Image
Old pickup coil on left...new on right
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Jittney
Anchorage 92 XFi

IGNITION ASSEMBLY
Long spring goes in the bottom on the left side
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Spring and ball bearing goes on both sides of the black center piece.
And see one of the 3 teeny tiny springs that go on the bottom of the black centerpiece.
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Next is the copper piece and then the top (outside) piece in back.
Now I see all 3 teeny tiny springs.
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MECHANICAL KEY/TUMBLER CLEANOUT
The mechanical key assembly has small openings on both sides of the metal cylinder.
Backside
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Key hole and underneath the key hole (usually covered by white box)
Posted ImagePosted Image
We poured denatured alcohol through it and worked the key until all the metal dust was cleared.
It still should have some graphite powder put in there for lubrication.
Hans put the distributor back together and broke a wire by the distributor connector quite close to the connector.
That's the bane of -15 degree weather.
He'll have to figure a way to fix that tomorrow.
We'll let you know if the repairs are successful. :)
Edited by Jittney, Jan 28 2012, 10:13 PM.
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Woodie
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That code means that the ECM is not seeing the spark happen at the coil. Could be thousands of reasons, only one of which is the coil. Blown fuse, bad relay, broken timing belt, distributor is laying on your dining room table, anything. Thew coil is just a transformer, as long as one side has a couple of ohms, and the other side has a couple of thousand ohms, it's gonna spark. The exact numbers don't matter a fig, they're just going to effect how strong the spark is. When you turn on the key, 12V goes to the coil and it charges up. When it's time for a spark, the 12V is removed, and the collapse of the charge is what makes the spark. When you turn off the key because you're giving up, the 12V is removed and a spark occurs. This tells me that there's nothing wrong with your coil or the power going to it, the problem lies in the trigger (in the distributor), the ECM (not likely at all), or the wiring in between (could be wiring, "module", noise suppressor, I don't know anything about your specific car).
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iBLKBRY
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Have you checked the ground distribution? If this car hasn't run for awhile... road salt, engine grounds, corrosion. I wish you had a garage with heat.
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Wolf
Member
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Jittney, you seem plenty competent to track down this problem yourself, but I hope you let us know the final fix incase I ever have the same problem. Fort what it's worth, I don't think a bad coil generates code 41 (only bad spark signal input), but I could unhook my coil to see if it generates 41 if that would be any help. Someone should collect a list of exactly what defective parts will generate each code for geo/sprints. I know there are some obscure cause/efects like mis-adjusted timing can cause the code for bad idle controller.

The only thing I might add that hasn't been said yet is maybe check the tachometer signal line for a short before assuming the knock controller is bad.
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