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i backfire when i rev high and switch gears? i dont know why this happens, anyone wants to enlighten me?
 

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It could be your timming or your EGR valve is stuck
My EGR valve is stuck right now :wink: I just got a new one (I just need to put it in :roll: )
 

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Does the backfiring only occur after you let off the gas? Is your engine running rich? What year is your MKII?
 

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Discussion Starter #4
yes it backfires only if i let off gas. its an 84 mk2. i dont know what running rich is? are you talking about the air/fuel mixture?
 

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Too much fuel in relation to the amount of air (Air/Fuel ratio) is known as a rich air/fuel mixture. Do you see black smoke coming out the tailpipe when you accelerate? Try checking your ignition timing. Maybe it has become retarded for some reason. (figuratively speaking that is 8)
 

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Well I just replaced the EGR valve on my car the timing is good and its backfiring. Im going to change the clamps on my intake cuz two of them were stripped and loose. Could that cause backfiring?



<-----Stealing this thread :twisted:
 

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Open the top cover that covers the two cam sprokets and timing belt. See if the timing belt moves when you try pulling it one way or the other with your hand. If it does then your timing sproket key or the keyway it sits in is worn.

Simple and easy to check, but it could be hard to fix. If it is only the key then easy to replace. If it is the keyway then the crank has to be relaced.,
 

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Check your DCSV(decelertion control servo valve) this wonderful little valve is supposed to shut off fuel when decelerating and can cause back firing if it isnt working..
 

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my car also backfires but not as loud as zank's. I will check the DCSV dohc82.
 

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Well i just finnished working on her and it seems that the backfiring had subsided. My timing belt felt a little lose so i tightend it up also my timing was under 10* so i set it at 15*. I feel the car ride a little smoother spescialy when shifting. THats my 2c.
 

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I'm not sure, but I think the deceleration fuel cut only occurs when you let off the gas above a certain RPM and with the clutch engaged.
 

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I don't know about you, but I loved when my car backfired under deceleration with my 5m. The whole time it decelerated, it would just be bop badabop pop pop badapop. Sounds kick ass on a DT header and straight exhaust.

Christian
 

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SUPRAMIR said:
i backfire when i rev high and switch gears? i dont know why this happens, anyone wants to enlighten me?
Are you back firing, or getting the pop pop pop sound when you let go of the gas?
 

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SUPRAMIR said:
yah, its the pop pop pop every time i let go of the gas at high rpms, isnt that what backfiring is?
Not really, all the cars actually do the pop pop pop, but when you have an exhaust that allows you to hear the engine more, you hear the pop pop pop sounds. Backfiring is when you start or hit the gas and the very loud bang under the hood, or out the tail pipe. If you don't want to hear the pop pop sounds, you can get a regular muffler on the car that chokes the engine out and you'll never have to hear it again.. In other words, when you tune for performance and sound that a side product of it, and it's NOT a bad thing.
 

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Reading the TSRM, about my own issues, the TPS is supposed to shut the fuel down when you let off the throttle. Check to make sure that is functioning.

It also says to check cold start injector.

If you have an exhaust leak, it could backfire also.
 
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