Constantly backfires

198,000 MILES • AUTOMATIC
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JENNIFERSTEPHEN SASSER
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My car has a LT1 engine. my car stopped running while I was driving it just shut off and now when I start it will not stay running and if I am able to get it to run for a few minutes there is a constant backfire coming out of back of car. do you have any ideas what what you think would be doing this? my husband is not sure so he just wants to go start buying parts and I really hate to put a bunch of money into it not knowing for sure what it is.
Jul 6, 2017 at 10:54 PM
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HMAC300
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scan for codes first see if anything comes up then get back to us with the code. but this is opti spark so it may be that bad.
Jul 6, 2017 at 11:44 PM
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JENNIFERSTEPHEN SASSER
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I cannot find a scanner that will fit car everyone has one for 1996 and newer so we changed cap rotor plugs and wires and again it will not stay running and backfiring again.
Jul 8, 2017 at 2:33 AM
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HMAC300
  • ✓Experienced Mechanic
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if this is a 1994 then cross A and B at scanner hookup with a paper clip and turn key on if any codes then check engine light will flash in a series of three so like one flash three times is one followed by two flashes equal 12 etc.
Jul 8, 2017 at 3:28 AM
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HMAC300
  • ✓Experienced Mechanic
  • 48,601 POSTS
See picture for items to check for causes, then if all this fails try to find if it is one or multiple cylinders. if you can pull one plug wire at a time to find the cylinder that may be doing this then pull that valve cover to see if it is a bent/broke push-rod or rocker arm problem.
Jul 8, 2017 at 3:33 AM
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