[T3] On a 73 T-3 SB fuel injected aut trans pinging .

[Jim Adney]

On 6 Dec 2017 at 16:28, William J wrote:

> Perhaps I have either a vacuum leak that comes and goes or a head temp
> sensor that is erratic. Also as you said Jim when I open the throttle and
> let it close it takes a second to drop to idle speed. At least the timing
> returns to normal much faster yet why it did ping once bugs me . I did get
> some where changing the dist .

It sounds like you were right about the other dist having a sticky advance 
mechanism, and it sounds like you've fixed that.

An erratic vacuum leak is certainly a possibility. I would check to see if you 
have the right FI air runner to head gaskets. (Have we been down this road 
before?) The correct gaskets are hard to find and don't come in any gasket 
set.

Also check to make sure the nuts are tight on those gaskets and that the 
(front) cover bolts on the IAD are tight. The sleeves on the air runners can 
also leak if the parts have been installed skewed.

See if you can find something to plug the inlet to the AAR, just to take it out 
of the picture. If the idle then settles down, maybe there's something erratic 
about the AAR.

I don't have any idea why you would have ping, unless this engine had been 
running extremely rich for a long time and had built up a bunch of carbon in 
the heads that could glow and cause pre-ignition. I believe you said this was 
an X engine, which should have the dished pistons giving and even lower 
compression ratio, which should make ping extremely unlikely.

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