I just bought a 1989 16V Jetta which ran fine when it was dropped off.
I left the car for a week and when I went to restart it, it wouldn't
start. Turned over fine and had spark. I checked the grounds, fuel
pump was running, checked for vac. leaks etc. When I tapped on the
fuel pump relay it did start and stayed running. I droved it about
half an hour, shut it off for about an hour and it re-started.
I left it again for a week and now, no matter what I do, it won't re-
start. The f/pump relay wasn't getting power so I replaced the knock
box with a good one I had laying around. Now the relay gets power but
the car still won't start.
Any idea's?

Fuel pump relay?
Bypass the relay and power the correct or large(?) terminals to power the
fuel pump to see if it starts.

"Rick" <farfi1 (AT) rogers (DOT) com> wrote

On Apr 6, 8:44 pm, "dave AKA vwdoc1" <vwd... (AT) hotmail (DOT) com> wrote:
I tried that first. But that's when the knock box fried. There is
power to both pumps and I can hear the main pump run. I can't be sure
that tapping on the relay was just a fluke. I would like to test a
fuel injector to see the spray pattern or even if it's spraying fuel
but I'm not sure how to do it correctly. I pulled the injector out and
grounded the body of it and turned the motor over (grounded coil wire)
but it didn't spray. Did I miss something?

If just jumping the proper terminals at the fuel pump relay caused the knock
box to fry...........then there are other problems. :-(
Unplug both fuel pumps and check the drain across those relay terminals.
You could test it with a inline fuse kit to see if the fuse blows.
Any rodent problems?

The cold start valve/injector requires starter current and a ground going
into it's plug. Not sure where your ground actually comes from for the cold
start valve/injector on your 16V. Also a coolant temperature sensor comes
into play. ;-)

"Rick" <farfi1 (AT) rogers (DOT) com> wrote

On Apr 6, 9:22 pm, "dave AKA vwdoc1" <vwd... (AT) hotmail (DOT) com> wrote:
I did replace coolant temp. sensor and therm time switch. Also
repaired some marginal wiring to temp. sensor. I seem to have a lot of
parts laying around from my other 16V.
Now if I disconnect both pumps what am I measuring across the fuel
pump relay? I'm thinking a correct measurement would be battery
voltage.
I did get a good spray pattern from the cold start valve with no drip
at shut off.

Funny you mention rodent problems. I have a 1982 GMC 1/2 ton with a
350 in really good shape. It doesn't get driven much so mostly it just
sits. I popped the hood one day in the fall just to check stuff out
and when I opened the hood the ENTIRE engine compartment was buried in
pine cones. They were everywhere. In every little crevice. Between my
header tubes, in the fender wells, under the carbs...it was amazing.
Then I looked in the glove box for a battery receipt and every piece
of paper was gone. I found it all later...shredded up to make a nest
in the hood latch opening. He doesn't live there anymore.
But this Jetta doesn't have any rodent issues that I've found exept
maybe gremlins-but they all do at some point.

I believe if you are measuring the amperage with the fuel pumps disconnected
it should be close to '0'. I think the only things that relay might power
are the fuel pumps. Not sure if it also powers the either the frequency
valve or the electronic fuel pressure regulator or ???. Not sure how the
knock box died! hmmmm
I would need to see the wiring diagrams.

"Rick" <farfi1 (AT) rogers (DOT) com> wrote

On 6 Apr 2007 18:46:35 -0700, "Rick" <farfi1 (AT) rogers (DOT) com> wrote:


http://www.driversfound.com/scirocco...e/knocksensor/
I looked at the wiring schematic for the 88 ( no 89 listed :-( bummer )
But there is a 10amp fuse between the coil and the two switches for
throttle position, and on the 88 diagram there is a feed to injection control
from the knock box.
Rodents : I use mothballs in 6 x 6 inch pouches made out of window
screening ( kinda like a envelope stapled on the sides with a fold flap
on top so you can replace the mothballs after they get old) in places
where the rodents like to build there houses. Two of these under the hood
of my 83 powerwagon ( a beater used only for snow plowing) keeps rodents
away. I also put these mothball pouches in my JD lawn tractor and an ATV.
I remove the pouches when I use the vehicles so I don't have to smell them
and replace them after use. A pain in the butt , but since I've been doing it
I have not had problems with rodents - I wonder what works for gremlins?

I wish that did work for gremlins! lol
Also you could try some bars of Irish Spring soap. I hear it works as well
as mothballs but has a better smell. ;-)


<samstone (AT) aol (DOT) com> wrote

snip

So the mice in my John Deere will be clean? Will my dogs still go
crazy hunting the rodents?

On Sat, 7 Apr 2007 08:24:24 -0500, "dave AKA vwdoc1"
<vwdoc1 (AT) hotmail (DOT) com> wrote:

On Apr 7, 10:25 am, Jim Behning
<jimbehn... (AT) doesthisblockpork (DOT) mindspring.com> wrote:
I'll have to go check the amperage and look for some fuses. I have the
wiring diagrams but for some reason they seam incomplete or at least
they don't show the full circuit from start to finish.
As an aside... I tried the soap trick...but the little bastards ate
it. That might of been Zest soap though.