[T3] Mysterious squareback condition.... need suggestions.

[Jim Adney]

On 25 Jan 2011 at 16:42, James Lingenfelter wrote:

> When I got home from work, I got it  started after much cranking and
> pumping on the gas, but then it idled  horribly and would die within
> 30 seconds if you let off the throttle.  And I witnessed it backfire
> once through the passenger side carb when  I opened the throttle from
> the engine compartment. From randomly  inspecting things in the engine
> compartment I discovered massive  corrosion at the plug wire
> connections to the distributor cap..... I  was already planning to
> replace them since one plug wire had shocked  me through the shielding
> recently. I consulted with my brother, who's  an auto mechanic, and
> determined that, considering the all-day rain  we had yesterday, that
> I indeed had an ignition problem probably  resulting from poor
> connections or arcing somewhere. 

Wet weather will play havoc with any car's ignition system, even one 
where all, or most of, the parts are in perfectly good condition. 
Here are some places to check. 

Pull the dist cap and check to see if there is condensation inside. 
If so, wipe it out, while being careful to not break off the carbon 
brush in the center.  

Check the spark plug gaps. If the gap has worn wide, this will 
require higher voltage to jump that gap, and that increases the 
chance that the spark will find a "better" place to go to ground. The 
gap should not be more than .028".

Look at the underside of your fan housing. Along the seam, right in 
the middle there is a hole about the size of a matchstick. Find the 
hole and poke a stick in there to see if its become blocked with 
dirt. If it's blocked, you may get water spilling out. That hole 
needs to be clear so water doesn't collect there and then get blown 
across the spark plugs when you start the engine.

Look at the spark plug cables. Do they have nice rubber boots on the 
SP ends that seal snugly all the way down the ceramic, so water can't 
get in there and short out the insulator?

BTW, corrosion on those HV terminals is not a problem. It doesn't 
slow down the spark one bit.

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