Date: Wed, 10 Sep 1997 08:47:19 -0700
Reply-To: Blake Heinlein <bhein@ECST.CSUCHICO.EDU>
Sender: Vanagon mailing list <Vanagon@Gerry.SDSC.EDU>
From: Blake Heinlein <bhein@ECST.CSUCHICO.EDU>
Subject: Re: Running rich
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Perry,
I spent about a month or so looking round in my engine to deduce
this problem. It was a combination of a lot of little things. My
engine got so rich it was backfiring at about 45 mph going down the
freeway. That was the max speed it would reach also. In that trip it
consumed about 15 gallons of gas in 100 miles, BIG problems.
What helped the most was putting clean spark plugs in. I then put
new rubber washers on the fuel injectors, and checked them also. I put
new cap and rotor on along with an O2 sensor. I still wasn't convinced
that things weren't working right. Pessimistic I guess?
I then went looking into the computer (ECU). I checked all of the
measurements with my multimeter and they were OK. Then I was told about
the wiring harness that runs over the exhaust pipe inside the engine
compartment next to the bumper. If that gets to hot it will create a
resistance in the wires and throw off all of the voltages in those
wires. I looked at mine and the PO had tied it up off the muffler heat
shield to prevent it form burning. It had melted the outer plastic
casing around the wires. So I dug in there. I stripped back the burnt
plastic to see how the wires were inside. They were OK. I rewrapped it
with electrical tape and zip tied it up off the heat shield.
I then to it to a VW mechanic and he checked my plug wires, (two
were bad, one with high resistance, & one the cable broke taking it
off). My timing was retarded also so he advanced it to where it should
be. He also did a compression check and I found I'm about 20 lbs low on
2 of my cylinders. Not bad for 150,000 miles.
Also to make my exhaust system quieter I put a new muffler on and
had my exhaust manifold welded where there was a crack from extreme heat
(right on the first bend out of the engine). I figured this could
effect the O2 readings if enough exhaust was escaping. Plus now it is a
lot quieter.
I know this probably sounds like a lot, but what else does a college
student do during the summer in Chico, CA when he's only working 30 hrs
a week.
I have only had my van for about 1 years so this was my first
encounter with problems. I hope that this gives some insight. :-)
Blake Heinlein
1983.5 Westy "Toaster"
CSU, Chico - Mechanical Engineering
Perry Patterson wrote:
> Hey,
>
> Did you ever solve your rich running Vanagon problem. I'm having the
> exact same problem. I put a new Ox sensor and it runs fine up to
> about 65mph and then blows a ton of smoke out the rear. Unplug the ox
>
> sensor and it's fine. Has done this with 2 different sensors. Traced
>
> part of my problem to an injector that was stuck open (run the motor
> and then shut it off. Pull the plugs and see if any of them are wet
> with gas. Take the one that is wet and unplug the wiring from that
> injector. Run it with clean plugs and if is still wet with gas you
> know it's a bad injector (they can start going bad and take several
> months to go full scale ballistic). A mechanic told me how to do this
>
> test. If the plug is still wet, then it is a computer problem.
>
> Let me know if you solved your problem or not. I need to solve mine
> before smog test time rolls around again.
>
> Thanks,
>
> Perry
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