Electrical Weak spark on #1 cylinder. Suggestions/Help

Blown88GT

Founding Member
Nov 13, 1999
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Palm Beach Gardens, FL
Bad (lifted) trace on the ECU circuit board. The bad cap "juice" will corrode & lift them. Look around the area of the replaced caps. It could be a pad lifted.
bad-old-capacitor-2-on-board-goop-2-450x363.jpg
 
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MrBottleneck

Member
Sep 12, 2018
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Ohio
Bad (lifted) trace on the ECU circuit board. The bad cap "juice" will corrode & lift them. Look around the area of the replaced caps. It could be a pad lifted.
bad-old-capacitor-2-on-board-goop-2-450x363.jpg
Sadly, no traces are bad. They are fine already inspected them all closely.
KOEO Test tested good with a 11 after caps done.
 
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Blown88GT

Founding Member
Nov 13, 1999
2,174
521
164
Palm Beach Gardens, FL
Weak spark only at #1 cannot be anything that's common to all cylinders.
Can only be bad spark plug, bad plug wire or bad connection.

Remove #1 plug wire & #1 plug & carefully inspect. I've seen spark plug clips inside the boot that don't attach firmly to the top of the plug.
 

MrBottleneck

Member
Sep 12, 2018
28
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54
Ohio
Nope thats not the issue I assure you. Did it with two sets of good plugs, two sets of wires, two caps and two rotors.
It’s something that has to do with ignition just none of those.
Furthermore if you re-read OP it states when cranking prior to engine starting it has good spark with SPOUT in but, once it starts it’s very faint to non existent. So, that in itself shows what I am saying.
Possibly coil now, TFI, or distributor.
If I get the time and not so tired from work I got a PM going on with a guy on this forum who wants me to do some tests that should help narrow it down.
 

91GTstroked

5 Year Member
Jun 14, 2007
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Not hijacking thread. But I've been dealing with problems as well. Finally pulled computer and found this. 2 of the 3 capacitors is leaking. The one with green fuzz is missing a leg.

I sent my computer off to ECU Exchange today. I could probably solder myself, but I want the whole computer checked out.
 

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MrBottleneck

Member
Sep 12, 2018
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Ohio
Not hijacking thread. But I've been dealing with problems as well. Finally pulled computer and found this. 2 of the 3 capacitors is leaking. The one with green fuzz is missing a leg.

I sent my computer off to ECU Exchange today. I could probably solder myself, but I want the whole computer checked out.
Yep, leaking pretty good at that.
Shoulda replaced them yourself. It’s easy to do.
Best of luck. Hopefully that will resolve your issues.
 
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91GTstroked

5 Year Member
Jun 14, 2007
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Yep, leaking pretty good at that.
Shoulda replaced them yourself. It’s easy to do.
Best of luck. Hopefully that will resolve your issues.
Yes I could do them myself. But they also run diagnostics. I want to make sure everything else is good.

I hope it does. Thanks.
 

MrBottleneck

Member
Sep 12, 2018
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Ohio
Well, thanks to 08GT500 and his recommendations and testing procedures with the accompanying Probst manual she is fixed.
What a good Fathers Day. My son came over and we continued testing following certain procedures and everything pointed to the HALL Effect Sensor aka PIP.
I had already ordered the reman. distributor so, I put it in.
That was problem. Something was a issue in the PIP as now I have good spark at #1 spout in. No more stumble and runs smooth as silk.
So, one thing is for sure I pretty much know every wire related to the ignition and EEC-IV on this car so, although It was a pain to narrow it down I enlightened myself tremendously on the way this particular ignition/eec-Iv works.

I had ordered (hasn’t arrived yet) a nice used OTC EEC-IV breakout box in the event I needed to delve deeper but, I will at least have it if ever needed now.

Big thanks to anyone who offered input and a huge thanks especially 08GT500.

Mike

A side note about the Probst diagnostic book is a great read and really helps out in diagnostics.
So, buy it if you can find a copy.
 
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