[Vwdiesel] More Quantum Questions?

Erik Lane eriklane at gmail.com
Fri Oct 30 19:38:45 PDT 2009

I've heard some people say that glow plugs only last them about 1
year. For me they seem to last much longer. Something like 5-10 years,
maybe more. They last so long that I lose track of just how long they
last, but I know that I can usually count on them. I don't even bother
testing them before winter comes because I can generally just count on
them working.

As far as putting air pressure to the injector - are you talking about
trying to push the cleaner clear through the injector with just air
pressure? That isn't going to work. It takes more than 1000 psi to pop
an injector in good shape. I don't work on them regularly, so I'd have
to look it up, but I think it's something like 1500-2000 psi. Of
course it's in bar for an imported vehicle, but that would be
something like 120-140 bar?

As far as your starting issue, I think the previously suggested weak
shut-off solenoid sounds like a solid guess and if you wire it to stay
on like also suggested it should be very quick and easy to test. Of
course air in the fuel is still a possibility, but with a smooth idle
and the fact that it acts the same whether it sits for 5 seconds or 5
days it doesn't sound quite right to be that, to me. Other people here
have more experience than me, though, so if they think it sounds good
they very well could be right.


On Thu, Oct 29, 2009 at 2:03 AM, William J Toensing
<toensing at wildblue.net> wrote:
> Thank you for your suggestions. 1) Pulled the glow plugs, found 3 good ones & one dead glow plug, the one closest to the front, or the # 1 glow plug. The 3 good ones tested between 5 & 6 ohms. However, since I had bought 4 new glow plugs from The Parts Place when I was in Mich. for the Hudson Centennial meet I decided to install the new ones although the 3 "good" glow plugs did glow nicely.  How long do these glow plugs last?Wonder if they will interchange with my Mercedes 300SD glow plugs, if any are bad? Haven't checked the Mercedes glow plugs yet as the Quantum is taking priority.
> In respect to starting, it was difficult to start even if I immediately tried starting it after turning it off while hot. However, I did find a copper washer missing from the IP outlet to the return line but no signs of leakage. However, I found an extra copper washer for the outlet banjo fitting so there is now a copper washer. I will also replace the return lines between each injector.
> I would like to test the injectors but wonder if there is a good tool I can buy to do this with, that can be bought reasonably. I also recall reading about a tool that picks up the pulse on an injector that is similar to a timing lite on a gas engine, for use in fine tuning the timing. Any comments, cost?
> I did remove all the injectors except  the # 2 one to get easier access to the glow plugs. I consider the # 1 glow plug to be at the front (cam belt side) of the engine. I also found the #2 glow plug difficult to remove & disconnected the cold start cable to gain access to re install the #2 glow plug.
> Now that I have all but the #2 injector out, would it pay to squirt carburetor cleaner into the injector  & blow it out with compressed air? Or could this damage the injector? Should I replace the injector washers like the Bentley manual suggests? I think I recall in a previous discussion a way of salvaging the injector washers.
> Bill Toensing, Nevada City, CA
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