[T3] Fwd: Engine Backfire

[Jim Adney]

On 18 Jul 2012 at 10:40, BilDylJ at aol.com wrote:

> My engine ran good for about 4 yr's. I had to leave it outside
> (covered} for about 2 mo. and it wouldn't start after. I had it checked  by 
> 2 { Certified } VW mechanic's they got  it running but it has been 
> backfiring on the left side 3 & 4 cylinders ever since. They can't  stop it 
> from backfiring. I thought maybe the rubber rings on one of the  injectors 
> were leaking air. There are no fuel leaks from the injectors or the  hoses.
> The engine starts and run's pretty good But it still starts backfiring  
> every time you let off on the throttle and hold it at a steady speed. {approx.  
> 30 mph}

Given all that, if it seems to run well on all 4 cylinders under full 
throttle, I'd look at the exhaust system. While I remain skeptical 
about this, others claim that leaks in the exhaust system can let air 
in during negative pressure moments, thus allowing enough air to make 
the exhaust mixture combust again.

Your mechanics should have adjusted the valves already, but if they 
haven't, that should be done next.

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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