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RANDOM MISFIRE PO300 HELP!!!!!!!!!

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  #1  
Old 08-07-2005, 03:50 PM
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Default RANDOM MISFIRE PO300 HELP!!!!!!!!!

I got a 97 camaro v6 RS, 3800 engine, I got a Random multiple cylinder misfire, SEL light flashing, i need a lot of help, i'm trying to do everything myself, new plugs, wires, o2 sensors, fuel injector cleaner, fuel sta-bilizer, new coils, i've tried everything. Please someone help me!!! I dont feel like paying the DEALER!

 
  #2  
Old 08-08-2005, 10:52 PM
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Default RE: RANDOM MISFIRE PO300 HELP!!!!!!!!!

If you are getting a misfire it has to be ignition related. Since you tried plugs , wires , and coils, the only other things I can think of is the ignition module under the coils (the brains of the ignition system) or unlikely the crank position sensors. If you want to do your own work, you should invest in an affordable scan tool, like "Auto X Ray" so you can see the data going and coming from the computer. A code reader is cheaper but it only tells you what the computer thinks it sees.
 
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Old 08-09-2005, 03:22 AM
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Default RE: RANDOM MISFIRE PO300 HELP!!!!!!!!!

Thanks for the advice, however I still have the problem but i have some more info if it helps... My friends tell me that i may have water in the tank, if i rev the engine for long periods the SEL lights stops flashing but stays lit.. I hear a bad misfire, and the catalyctic converter really shakes a lot.
 
  #4  
Old 08-09-2005, 01:30 PM
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Default RE: RANDOM MISFIRE PO300 HELP!!!!!!!!!

You need to find out what trouble codes the SEL light is complaining about, and you need a scantool or at least a code reader to get the codes out. Some shops will read the codes for about $50, or you can try Auto Zone (if there is one in your area) and get it done free. In the meantime check your ignition wires & make sure they are not crossed. The coils towers are marked with numbers that show which plug they need to be connected to. Each coil fires 2 plugs.

If you have water in the tank, you may try dumping in several cans of dry gas or a gallon of 100% alchool (200 proof if you want to use booze) to soak the water up, replace the fuel filter because it is supposed to trap some of the water. Otherwise you can try to pump the tank out completely which is almost impossible, or drop the tank & clean it out, which calls, among other things, for dropping the rear axle.

Have you replaced the ignition module, the box that sits under your coils? These things do go bad an cause havoc.

There is a possibility of a bad injector being stuck open and dumping excessive fuel, which can give you backfires, but very unlikely.

Watch the backfires, they can blow out your catalist and muffler.
 
  #5  
Old 08-09-2005, 10:34 PM
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Default RE: RANDOM MISFIRE PO300 HELP!!!!!!!!!

Great news i solved the problem, i went to a shop got it scanned and the second ignitin coil was the problem, i changed the wrong one, $520 dollars later my car has everything new for a little $30 mistake, heres a hint for you guys GET IT SCANNED! some things are better left to the PROS! thank you for your help. You guys gave me the support i needed to wake up and admit when I needed help!
 
  #6  
Old 08-09-2005, 11:36 PM
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Default RE: RANDOM MISFIRE PO300 HELP!!!!!!!!!

Glad u fixed it. But if you insit on working on computer controlled cars, you need a scan tool and a genuine factory repair manual.
 
  #7  
Old 08-10-2005, 11:44 AM
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Default RE: RANDOM MISFIRE PO300 HELP!!!!!!!!!

Yeah my car is much better now, however i'm still gettng a noise from the cat,, i think I'm going to change that real soon!! Once i put in my dual exhaust flowmaster
 
  #8  
Old 08-10-2005, 01:18 PM
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Default RE: RANDOM MISFIRE PO300 HELP!!!!!!!!!

The backfiring most likely broke up the stuff inside of the cat and the fragments are rattling around. I have seen this stuff get blown intothe muffler where it gets caught and chokes up the exhaust sytem. If you find that your car looses power almost like letting off the gas, and then takes off again, this is probably what is going on. You should change your cat before getting new mufflers.
 
  #9  
Old 08-11-2005, 01:03 AM
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Default RE: RANDOM MISFIRE PO300 HELP!!!!!!!!!

I think your right, my cat is making noise and the car is doing that thing with the gas pedal,, i will really look into that. Thanks
 
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