LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Terrible Missfiring

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Old Oct 14, 2007 | 03:44 PM
  #1  
mannycamaro's Avatar
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Question Terrible Missfiring

hey Quys Once again:

NEED HELP:

I LT1 is missfiring I ve had the problem for the last 3 months and keep poping back up.

on 10/14/2007 had tailor cut and fit wireing installed so that headers won't burn cables, took car into mecanic with the missfirng and had it wired.

After getting car out of garage an in 15 minutes it started to missfire once again.

It is throwing black smoke out of tail pipes and very heavy to the ground.

Things done recently :

1- New original GM Opti Spark, after instalation mecanic told me my my factory Opti is in good condition and problem was burnt wire cable by header.

2- Two set of original wiring spark cables both getting burnt.

Know mecanic says it could be the O2 sensors ?????

Can anybody help me.

getting broke.
Old Oct 14, 2007 | 03:55 PM
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Did you have the plugs changed along with the wires? Some of the plugs may be fouled which could cause misfire/backfiring.
Old Oct 14, 2007 | 03:59 PM
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If the car is running fine, then the wires burn and it misfires, it's obvious that the problem is burnt wires.

My car started misfiring really bad, turned out the wire on the #6 cylinder was burnt to a crisp. Put a new msd in and the problem was solved.

It's very difficult to route wires with headers.

I'm going to invest in an over the valve cover kit this winter. I've blown a lot on wires, and I still have wires on my car that are a little burnt up.
Old Oct 14, 2007 | 04:05 PM
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Originally Posted by blueformula350
Did you have the plugs changed along with the wires? Some of the plugs may be fouled which could cause misfire/backfiring.
No I didn't.
Old Oct 14, 2007 | 04:08 PM
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Originally Posted by raroz28
If the car is running fine, then the wires burn and it misfires, it's obvious that the problem is burnt wires.

My car started misfiring really bad, turned out the wire on the #6 cylinder was burnt to a crisp. Put a new msd in and the problem was solved.

It's very difficult to route wires with headers.

I'm going to invest in an over the valve cover kit this winter. I've blown a lot on wires, and I still have wires on my car that are a little burnt up.
The problem is that I had the wires put in new.They are Tailor cut and fit and I instaled and over the valve cover with them,but is missfiring like hell
. left mecanic garage and 15 minutes later it started to miss fire.
Old Oct 14, 2007 | 04:22 PM
  #6  
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Throw some ngk tr55s in there (1.60 a piece) and see what it does. If that doesnt work take a spray bottle and fill it with water then spray the wire, coil, etc and look for arcing.
Old Oct 14, 2007 | 04:25 PM
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Originally Posted by mannycamaro
. left mecanic garage and 15 minutes later it started to miss fire.
are the wires burnt now or not
Old Oct 14, 2007 | 04:38 PM
  #8  
mannycamaro's Avatar
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Originally Posted by dangalla
are the wires burnt now or not

No they look like new. I put (OVC) kit so the cable aren't making contact with the headers.
Old Oct 14, 2007 | 04:45 PM
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From: Ottawa, KS
It may be the coil pack going out, my car would miss and stumble when it was going out.
Old Oct 14, 2007 | 05:51 PM
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I would test the ignition system. Coil, ICM and opti... It's on shbox.com, sounds like a coil.
Old Oct 15, 2007 | 04:44 PM
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Ttt
Old Oct 15, 2007 | 11:58 PM
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I will change spark plugs tomorow, to see what happen .
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