[T3] Intermittently running on two cylinders

[Jim Adney]

On 2 Dec 2012 at 21:29, Jacob Adam Schroeder wrote:

> The problem occurs (when it does) at idle on a cold engine.  Although, just
> because the engine is cold does not mean I'll have the issue, but when it
> does happen, it is on a cold engine at idle.  Revving the engine up (no
> matter how high) will not remedy the problem.  It just revs up the 2
> cylinders.  You are correct with there being NO power when this happens.

Do you also find that this occurs while driving?

There's a problem that these cars sometimes have, of some cylinders 
running overly rich while cold and essentially flooding a cylinder or 
2, depending, I assume, on some of the injectors flowing a bit more 
fuel than others. Once this starts, it's almost impossible to get it 
to quit, especially if it involves #4, which heats the cyl head temp 
sensor, because fresh gas keeps adding to the unburned fuel in those 
cylinders.

One of my cars would do this pretty consistently, but I found that I 
could get past it by limping it up to about 30 mph and then taking my 
foot completely off the throttle in 2nd gear. If the throttle valve 
switch is correctly adjusted, this shuts off the FI while the engine 
slows down, being driven by the car and pumping air thru all 4 
cylinders. This flushes out the flooded cylinders, as well as the 
others, and leaves them ready to go once I got back on the throttle.

Once I started doing this on my way to work each morning, my morning 
commutes went much better, and I'm sure it was much better for the 
engine. It took less than 1 block of residential driving to cure 
this.

This may not be what you're experiencing, but it's worth checking 
before you start putting heroic efforts into finding a cause that's 
not really there. It's also something you can try in the course of a 
normal day, with no real extra effort.


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