injection problem?

Hi everyone,

I'd need a hint with a problem I recently had on a 82 aircooled westy.

Engine began to run rough... and deteriorated his fuel cunsumption,
down to 60 miles for one full thank. Timing was checked and found ok.
All 4 plugs were dark,indicating too much fuel. Engine has 20k miles
since rebuilt (from somewhere near Pasadena, Ca.). Bus is still on the
road... Any hint of what the trouble could come from? Can I work it
out on the road or do I need a expensive towing? (I'm stuck in the
middle of nowhere...).

I guess this has to do with the electronic injection... What should I
check first?


Thanks

Steph

Steph wrote:

> Hi everyone,
>
> I'd need a hint with a problem I recently had on a 82 aircooled westy.
>
> Engine began to run rough... and deteriorated his fuel cunsumption,
> down to 60 miles for one full thank. Timing was checked and found ok.
> All 4 plugs were dark,indicating too much fuel. Engine has 20k miles
> since rebuilt (from somewhere near Pasadena, Ca.). Bus is still on the
> road... Any hint of what the trouble could come from? Can I work it
> out on the road or do I need a expensive towing? (I'm stuck in the
> middle of nowhere...).
>
> I guess this has to do with the electronic injection... What should I
> check first?
>
>
> Thanks
>
> Steph
>

First thing would be the #3 cyl head temp sensor.
Got a Radio Shack store nearby?
Resistance of the sensor should be ~2500 Ohms cold.
Goes down to ~100 Ohms hot.

Get a RS potentiometer (volume control) with at least 2500 Ohms
resistance. Could be 5000, 10,000... Wire it from chassis
to the sensor lead that goes into the harness (unplug the sensor).
Now you can "fine-tune" the thing as it warms up.

Next easiest thing to check is fuel pressure. Should be a
test port on the fuel ring on the left side. Get a 60psi gauge
at auto/hdwr/bigbox store and connect with hose.
Should read ~35psi (varies with vacuum). You are looking for
a reading way over that.

Harder to test, but next would be a stuck-open injector.
If ALL the plugs are oily/dark, it's probably not an injector.

--

Speedy Jim
http://www.nls.net/mp/volks/