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· 4ZUA787
664 Posts
wiring diagram

i took the wiring diagram for my 72 gt and enlarged very big and hung it on the wall very easy to trace a wire from any were in the system of wires. although they do use very confusing colors for some of the wiring. but helped a million to enlarge it.

· Über Moderator
6,671 Posts

I am beginning to think that the Opel PCV system has become my "raison d'être"! ("reason to be")

The big valve cover hose serves TWO purposes. As Gene has said, it allows crankcase fumes to be vented out from the valve cover, preventing the buildup of pressure in the engine. But this only happens at higher revs, unless the engine is seriously tired, and has significant ring blow-by and/or leaking valve stem seals. In this case, the engine develops more blow-by gas than the smaller hose (which should be routed to the PCV metering orifice on the intake manifold) "sucks" out of the crankcase, and gas fumes flow out from both valve cover ports.

But if you have a reasonably sound engine, at an idle (and high manifold vacuum) the PCV metering orifice sucks more gas volume than the engine creates, and the big hose acts as a "makeup" air supply, keeping the crankcase from being drawn into a vacuum. If the big hose is simply open (and not connected to the inside of the air filter), dirty air is drawn into the valve cover, and in turn into the small PCV hose. So the dirty air enters the combustion process, and this is not a good thing.

Connect the big hose to connector INSIDE the air filter, such as this (the big hose connects to the left side of the tee; I have chosen to connect the charcoal cannister to the right side of the tee, killing two birds with one tee):


· Opeler
25 Posts
Discussion Starter · #23 ·
what fire hazard?

thanks for the replies. im about to remove the engine!

kwilford: the hose was very gunky. the carb didnt have a filter, and the grey/black foam padding stuff was deteriorating and was surreptitiously being sucked into the engine. not sure what ill find inside.

i pulled the plugs, very sooty.

i took a look inside the headlight assembly to see if the PO changed the headlight wiring...


· Pathologic Opeler
1,956 Posts
my experience as opel newbie to vurx

...I am an opel newbie too...I have been waiting 3 weeks to get
my backordered manual from "motolit.". so you may have to work off info that you can gleen from the opel gt.com site.Ebay might be a better to place to "buy it now"manual.

I think most shops will want a manual to work on certain problems...I have not needed it yet.

I did need a shop to get my opel running, to do things I could not do..(e.g.-I needed a gas tank pulled and welded..plus I had a cracked firewall that need braced and welded at the clutch/brake interface)..NOT simple things for a newbie.I did not want to blow myself up.

Here is how I found good mechanic...there are no opel people in
Kanasa city that I know of..."find your local MG club..call the local
club members and see who they use...many of these clubs hang out at certain shops..and they will treat you fairly".Worked for me.

PS:The opel Gt is a great car..yours will is coming along.I had similiar problems with hoses and Wilford helped me out too.there are photos of my hoses too...I think you can search "bucky"
to find ny photos.

Oh by the way..how did you "enlarge the photo with the square''
that was cool.
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