[T3] Marigold's story

Fri Jun 27 20:11:18 PDT 2014

Wow, what a process!  Sounds like you restored the entire FI system, and
then some, and all this acting up when it gets to the invasion, almost as if
it was waiting to get to where it knew the experts were!

Keith

Top Notch Restorations
topnotch at nycap.rr.com 
http://www.a383ina68.addr.com/radiorest/main.htm
71 Squareback "Hothe"
65 Notchback "El Baja Rojo"
65 Squareback "Eggcrate"
87 golf "Winterat"
93 RX7 "Redstur"

-----Original Message-----
From: type3-vwtype3.org [mailto:type3-vwtype3.org-bounces at lists.vwtype3.org]
On Behalf Of Jim Adney
Sent: Friday, June 27, 2014 9:06 AM
To: type3 at vwtype3.org
Subject: [T3] Marigold's story

Those of you who made the Invasion met Sarah there and know about her 
car's problems, but some of you asked for a review of what was wrong 
and what we did. I wrote this up from memory, so I'm sure I've gotten 
some things out of order and probably left some details out. 
Hopefully, I've managed to include all the important parts.

Here's what happened:

Sarah bought her yellow '71 Squareback, Marigold, out of Washington 
state about a year ago. When she got the car, she had it worked over 
in Ohio, where she grew up and her parents still live. Since then, 
she's been living in Brooklyn, NY and driving Marigold to work almost 
daily. She had made a few trips back to Ohio in the past year and 
felt that the engine was working normally. This trip was different.

On her way here, Marigold began to bog down and eventually would not 
go over 30 mi/hr. Sarah called John J. Thursday evening and explained 
that she had pulled spark plug wires one at a time and found that # 1 
& 3 did not seem to be doing anything.We agreed that she should try 
to get to Watkins Glen where we would meet her Friday morning and 
figure out what the problem was.

After the drive around the track, we met Sarah and proceeded to look 
Marigold over. There were no obvious broken wires and everything 
looked pretty normal after a quick visual inspection. I got out my 
Bosch FI tester and ran thru the usual tests and found that one of 
the wires to the intake temp sensor was broken. So that got fixed. 
The FI plug to the distributor also seemed loose, so I pulled those 
pins and tightened them. One of those wires was down to just a few 
strands, so I replaced that terminal.

In the course of those tests we ran the starter with the brain 
disconnected. To my surprise, the engine started and ran for 10-20 
seconds. This indicated that there was excess fuel still sitting in 
the cylinders, so it seemed clear that the poor running had been 
caused by excessive richness, which the broken wire would have 
caused. I assumed the broken wire was the problem and we started back 
to the host motel.

Partway to the motel, Marigold bogged down again and could no longer 
keep up. We stopped and I replaced the #1 spark plug, which was WAY 
carboned up, with a used one which I had bead blasted and brought 
along as a spare. That got us back to the motel, but there was 
clearly another problem. After inspecting the plugs again, I replaced 
both #1 and #3, again with used, blasted plugs. Then we checked the 
dwell and timing and found the timing retarded, so we corrected that. 
That seemed like an improvement, but when I mentioned the broken wire 
to Keith, he said that that would have made it run rich, but not THAT 
rich. That got me worrying again.

I spent the night trying to think of what else could be wrong. By 
Saturday morning, I was ready to check the pressure sensor for a 
broken diaphram. Indeed, it was. So we spent some time looking for a 
kluge or replacement. Dave P. brought in some supplies that I hoped 
would provide a way to make Sarah's sensor temporarily functional, 
but Lyndon saved the day when he came up with the exact proper part. 
We installed it and thought we were done.

Sunday morning we went at it again, since some test driving still 
showed poor running and a lack of decent power under certain 
conditions. So I went thru the Bosch FI tester sequence again. This 
time I noticed that the trigger point dwells weren't symmetric, so I 
pulled the distributor to look at those points. I found worn rubbing 
blocks running on a rather rough, dry (no lubrication) cam. I cleaned 
up the cam as best I could under the circumstances and applied Bosch 
cam grease. I applied a bit of motor oil to the dry trigger point 
pivots and tried to work it in. At that point it became obvious that 
these pivots were so sticky that they were not closing properly. So I 
swapped in a spare that I had brought with me.

We re-installed the distributor with the "new" trigger points and 
re-timed the engine. Then we paid attention to the pressure gauge 
that I had installed on the fuel line for the earlier tests. The 
pressure was somewhat low, about 26 psi, so I cranked that up to 30, 
but the more disturbing problem was that the gauge needle was 
vibrating over a range of about 5 psi and there was an odd vibrating 
noise coming from the fuel line itself. Normally that reading is 
steady.

I decided to check all the injector pins to make sure they were tight 
enough. All the terminals on #3 & 4 injectors turned out to have been 
replaced with non-locking terminals, so I replaced all 4 of those, 
and when reinstalling them it became clear that they had been plugged 
into the wrong injectors. The #1 & 2 pins were a bit loose, so I 
tightend all of them.

Thinking we were done, I decided to re-route some hoses to neaten up 
the engine compartment and tried to remove the hose between the AAR 
and the Intake Air Distributor. That hose shattered into 4 pieces 
when I tried to remove it. The 5/16" fuel hose I had with me was too 
small to replace it, so Dave drove home and came back with some 3/8" 
hose that worked perfectly.

The odd fuel pressure readings and vibrations had me worried about 
the fuel filter, so we jacked up the front end and I pulled the hose 
off the output end of the odd aftermarket filter that I found there. 
Out came a bit of a trickle, rather than the gusher that should have 
been there. So I plugged that end and pulled the hose off the inlet 
side of the filter. THERE we had a gusher, so the filter screen in 
the tank was okay, but we replaced the aftermarket filter with a good 
used Bosch.

Replacing the filter quieted down the pump, settled down the pressure 
gauge needle, and eliminated the "vibration" coming from the fuel 
lines. I'm guessing that the pump was struggling to pull enough fuel 
from the filter, so the suction the pump created was pulling in air 
bubbles which were yet another problem on top of insufficient fuel. 
After replacing the filter, we had to readjust the fuel pressure back 
to 30 psi.

We installed my overflow hose and vent kits and while the trunk was 
open, we removed the gas gauge sender, just so we could look into the 
tank and see what was in there. The tank looked clean, with only a 
small amount of dirt and no sign of water.

Finally, to cover all the bases, I replaced all 4 spark plugs with a 
set of new Bosch WR8AP (Platinum) that I had. I was hoping these 
would not foul as quickly, in case we still had undiscovered 
problems. The idle seemed low, so we boosted it up a bit, then we 
took a long test drive. Marigold drove well and no longer put out 
black smoke on full throttle. But after the shakedown the idle was 
high again and we moved it back down. Everything seemed good, but we 
were all still concerned that the problem would return after about an 
hour of driving, as it had each time before. By then it was getting 
late on Sunday and Sarah agreed to try her luck and head back to 
Brooklyn.

She made it and now reports that things seem good except for some 
difficulty starting and in the first few minutes of running. I 
suspect that she needs my primer kit, to run the pump and clear air 
out of the fuel line after a hot shutdown. Her Aux. Air Regulator may 
also be sticking, which would make a cold start hard to keep going.

I think she's nearly done; Sarah will be able to do those things that 
may still need to be done.

Sarah asked which of the fixes we did was the important one. I have 
to say that Marigold had several problems which were major. Here's 
how I rank the problems we found:

Major: pressure sensor, trigger points, fuel filter

Medium: injector pins, broken overflow hose

Minor: broken temp sensor wire, frayed wire on trigger point 
connector (would become major)

Note that the pressure sensor and broken temp sensor wire would have 
made the system run rich, but the low fuel pressure and clogged fuel 
filter would have 
pushed things lean. It's likely that the engine ran correctly under 
some 
circumstances, but I suspect that it was running extremely rich in 
downtown 
driving, which is where it spent most of its running time.

The only one of these problems which could have gone on forever 
without becoming a big problem was the first one we found: the broken 
wire on the temperature sensor. This turned out to be a red herring 
because it was easy to find, and I got distracted and assumed 
everything would be fine once it was fixed.   

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

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