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Supra Owner Since 1996
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Discussion Starter #1 (Edited)
I had started to notice a small single miss and changed out my plugs before heading to the drag strip this weekend. I was running 118 octane fuel so it was hard to tell if the miss was present or if it was the high octane.

Back on pump fuel now the car sounds like it has 2-3 misses. OBDII threw out a 0301 code today for a miss in #1 cylinder. Pulled the plug and it looks good. I assume the only other culprit could a a coil pack or ignitor. Let me know if there is something else to suspect.

6097's gapped .022 @ 24 psi

Thanks, Andy
 

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one other guy on this forum having same problem i suggest narrowing the spark plug gap on # 1 cylinder until miss goes away before replacing plugs and coil pack. another thing you can do is switch #1 and #2 spark plugs and then if you get a code PO302 then the spark plug is the problem you can do the same thing with coil pack.
 

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Supra Owner Since 1996
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Discussion Starter #3 (Edited)
NOT EXIST said:
one other guy on this forum having same problem i suggest narrowing the spark plug gap on # 1 cylinder until miss goes away before replacing plugs and coil pack. another thing you can do is switch #1 and #2 spark plugs and then if you get a code PO302 then the spark plug is the problem you can do the same thing with coil pack.

I actually did swap one and two and reverse the coil pack with no difference. I am going to try driving it and see if it throws the code again. Smaller the gap and the rougher the car will idle causing harder detection of the problem. Only need to lower the gap if it is breaking up on top due to the spark being blown out. Only at 18 psi on the street.
 

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Stock Twins King
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Hey Andy, hows it going!

I would guess to say that your #1 Injector is starting to die. People always never think that injectors require maintenance. Before I cleaned my injectors I was taking out 12-18% fuel in my AFC, now I am taking out 22-28%. And that was injectors that were spraying at about 75%. (before replacing/cleaning) Not saying that is the problem, but worth looking at if they have never been tested.

Taken a compression test on the #`?
 

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Supra Owner Since 1996
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Discussion Starter #5
Stu Hagen said:
Hey Andy, hows it going!

I would guess to say that your #1 Injector is starting to die. People always never think that injectors require maintenance. Before I cleaned my injectors I was taking out 12-18% fuel in my AFC, now I am taking out 22-28%. And that was injectors that were spraying at about 75%. (before replacing/cleaning) Not saying that is the problem, but worth looking at if they have never been tested.

Taken a compression test on the #`?
Thanks for the advice Stu. I will do a compression test when I get home and consider the injector. Maybe I can use this as an excuse to build my fuel system. I have noticed that while watching my WB, instead of varying between 14.5-14.9 afr at idle and cruise it will bounce down to 13.9 when it hits the miss. Which probably accounts for the unburned fuel in that cylinder. I will maybe head over to Brett's and swap in some of his coil packs. We all know his car isn't going anywhere.
 

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Supra Owner Since 1996
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Discussion Starter #6
Update for today: I did a compression test last night and it was 150-155 across the block. I then wanted to test if the miss followed the coil pack or the plugs. I swapped 1/2 coil pack with 3/4 and also replaced plugs in cylinders one and two with the old ones that were removed. Drove it around last night and could hear the miss but no engine light. It finally threw it this morning and gave me a code for a miss in every cylinder but 3 & 6. Now i'm getting kind of stumped since it's not following a particular coil pack or plugs. Only problems I have heard with ignitors is that they either work or they don't.

Anyone have any ideas yet? I'm changing out my fuel filter tonight just because it needs it.

Thanks
 

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Does the car idle fine when you started in the morning like its not missfiring or running rough while idling. Measure the resistance of every ignition coil with Digital ohm meter to see if its not out of specification.
 

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Supra Owner Since 1996
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Discussion Starter #8
NOT EXIST said:
Does the car idle fine when you started in the morning like its not missfiring or running rough while idling. Measure the resistance of every ignition coil with Digital ohm meter to see if its not out of specification.

Kind of does idle normal when warming up in closed loop. What I don't understand is how one cylinder was bad? I moved that coil and now 4/6 are bad.
 
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