LT1/LT4 Tech 1993-1997

Threw timing belt?

  #1  
Old 07-27-2012, 05:31 PM
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Default Threw timing belt?

On my way to work, car was running fine. All of a sudden started backfiring like hell and died. I coasted it onto a dirt road and now it wont run. It turns over like it wants to start, and then starts backfiring and missing real bad. Turn the key off and it tries to run a for another 30 seconds or so. What the hell is going on?
 
  #2  
Old 07-27-2012, 06:55 PM
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Someone told me it sounds like an opti problem? Any thoughts?
 
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Old 07-27-2012, 07:42 PM
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Well, I can guarantee that it isn't the timing belt. The LT1 doesn't use timing belts, it uses the tried and true timing chain.

Now, what year car do you have and how many miles on it? What is the maintenance history? Has the opti ever been changed?
 
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Old 07-27-2012, 07:46 PM
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Engine? Miles?
 
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Old 07-27-2012, 08:33 PM
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sounds like the rotor let lose or opti scanner is failing. can you scann for trouble codes? chain could have jumped a tooth or two on the timing gears. lose wire or bad connection to opti or ignition coil module, pcm or tune gone bad, all i can think of, i dont know if a failing icm will do what you are seeing but have not seen it.
 
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Old 07-28-2012, 02:44 AM
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1994 z28 lt1, 20,000 miles on rebuild, opti os a month old.
 
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Old 07-28-2012, 04:24 AM
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I did a youtube search for "opti spark," and watched about a dozen videos of bad ones and of them failing. Pretty much EXACTLY how my car died and how it acts now. Think i may have found the problem! Earlier today when i got home it seemed to be running a little hot, i popped the hood and a little coolant was seaping out around the radiator cap. Im now thinking that needing a new $5 cap just fried my opti...
 
  #8  
Old 07-28-2012, 07:44 AM
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When you replaced the opti, what brand did you use? Some brands are pretty shoddy and while they all look alike, looks can be deceiving.

Unless the coolant was leaking on the opti itself, it is doubtful that a leaking radiator cap is the root cause of your failure.
 
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Old 07-28-2012, 12:03 PM
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if the opti or icm or computer is failing it can mess with the timing and cause increase in temp. so its running now?
 
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Old 07-28-2012, 02:17 PM
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I didnt do the replacement. The opti was replaced by the previous owner a week before i got the car. It was a RichPorter opti. I still have the box it came in and the old one. Somewhere (fingers crossed) i have the receipt from oreillys for the $240 something that he paid for it a month ago.
 

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