[T3] Mysteries and FI Parts

[Jim Adney]

On 10 Aug 2011 at 16:33, Jeremy Menzies wrote:

> Whoops, sorry for the huge run on sentence.  A combination of thinking
> I could 'make it quick' by making a huge list and an excessive amount
> of coffee are to blame for that one...  Thanks for weeding through it
> anyway. 

Leave a complete blank line between paragraphs. That assures that 
they don't get run together on the other end. I still had to separate 
each of your thoughts out.

> Trigger Points: Interesting about the dwell drifting.  The guy I'm
> working with said he had a couple of sets from a good 914 that I could
> try out, so I think I'll check those out and see what happens and if
> it's no dice then it's quite possible I'll be sending them your way
> ($10 sure beats the $114 for a new set!)  I've actually debated
> getting a Bosch machine out of curiosity and a desire to be able to do
> quick tests all at once but I'm concerned about blowing cash on a dud
> unit... 

$10 for adjusting one set, but $5 for each additional set done at the 
same time. So I could do all 3 for $20 plus return shipping.

The Bosch tester will tell you if the points are out of adjustment, 
but it won't help you adjust them. Bosch just wants you to replace 
them. It's possible to adjust them using their tester, but it's trial 
and error: You have to put them back in the distributor, install the 
distributor and start the engine to see how you're doing. That can 
take hours.

> Injectors: Do you mean the pins in the body of the injector that the
> plug slips onto?  I didn't tighten these up and I'm not sure how.  I
> carefully pulled the female 'faston' terminals out of the plastic plug
> housing and cleaned and tightened up the curled ends and the crimp on
> the wire. 

I meant the fastons. Sounds like you've done that.

> AAR: It's quite possible that I just haven't run it long enough for
> the oil to get hot enough to close the regulator.  After my 2+ mile
> drive it felt like it was sucking as strongly as when I first started
> and when I plug it the idle drops considerably (I'd say down to 850 or
> so plugged from 1600+ open). I did pull it out and take it apart to
> free things up and lubricated with some clean oil.  I also tested it
> with some heated oil in the kitchen, slowly heating and checking to
> see if and when it closed.  It snapped fully closed at around 150F,
> maybe a little hotter but it doesn't seem to close like that in the
> car.  I left the adjustment on the spring where it was set (all the
> way to the '+' side of the scale) but I'm not sure what the + and -
> are supposed to indicate exactly. 

This sounds fine, except that it shouldn't "snap." It should close 
slowly as the temp rises. Sounds like yours has a sticky spot. That's 
consistent with your comment yesterday that suddenly the car wouldn't 
idle.

I've found that often the die cast body warps over time and catches 
the rotor in one spot. Find that high spot and sand it down until the 
rotor can spin smoothly. You'll have to take the AAR completely apart 
to do this. The tight spot will be inside the large diameter part at 
the top. Make sure you wash out all your sanding grit when you're 
done.

> TVS: I'd like to take a look at your write up on this. 

Okay, I'll send you my instructions. In the meantime, unplug it as a 
test.  

> Timing:  I have set it to what I think is 0 TDC using the diagram in
> the Bentley (looks like: |   | | |  the first line to the left being 0
> deg then 5, 7.5, and 10?)  Set with both a static light and then
> rechecked and adjusted with a strobe.  I had the idle set at 850 with
> the strobe.  When I open the throttle, I can see the marks move left
> of the pointer on the fan housing (marks go this way facing engine
> <---- ) so I assume that means it is advancing.  Plus the vacuum
> chamber moves the breaker plate and holds a vac. and the centrifugal
> weights are moving freely, so I assume they're working OK.  I haven't
> done anything to check how far it's advancing but it moves past the
> right most mark (is this 10deg BTDC?).  I used the 0deg. mark prior to
> when the problem cropped up and the engine ran fine as far as I could
> tell, so I assumed it was correct.  There are some other cast marks on
> the pulley that are further to the left that are not illustrated in
> the Bentley, though so perh aps I'm not timing it to the correct one. 

It sounds like you're doing this right and everything has checked out 
nicely. The leftmost mark is TDC, but, FYI, the others are 7.5, 10, 
12.5.  

> Ignition Switching Clicks: I definitely hear one and the whirr of the
> fuel pump, I'll have to stick my head down there again and listen more
> carefully for two.  I'm pretty sure there's two, though.  I assume
> this is the pump relay clicking?

The first click is the main FI power relay and the fuel pump relay 
coming on at the same time. The second click is the fuel pump relay 
turning off after about 1 second. The pump should whirr between the 2 
clicks and then go off.

> Another thought I had was maybe some water got into the ECU because the
> problem cropped up after the car sat in the rain for a few days and it
> happened briefly once before during a heavy rain.  Although, when I
> looked at it it didn't look like it had leaked and the car ran fine in
> between the first time and the current extended issues. 

After a rain, or after using a garden hose to pour a lot of water 
into one of the side air intake louvers, go under the back of the car 
and with a large wire, find the drain hole that's in the bottom 
center of the fan housing. Poke up into that hole and see if water 
suddenly comes out. That hole gets plugged with debris over time and 
lets water accumulate in the fan housing during a rain. Then, when 
you start the car, the fan sprays that water over the engine, 
including the spark plug insulators. That can cause rough running 
until the engine heats up and drys off.

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