AAR Diagnostics - 1978 Bus

[bretski]

In trying to track down my stumbly cold idle issues, I pulled the AAR today. Got it all cleaned up, and here's what the opening looks like at ambient (approx 92*F today):



I put 12 volts on it, and it closes completely within a couple of minutes. I put my voltmeter on the plug, and see 12 volts when cranking. I also get 12 volts across the plug with the engine on (that was a feat of acrobatics, BTW, with one hand holding the test probes in place while trying to block off the 2 ports at the same time ).

So, is this open enough when "cold"? Should I increase the opening a bit?

Side-rant: My F#$%ing AAR elbow is cracked...again...less than 2 years after replacement, and this was supposedly the "good" German elbow.


RTV'd the SOB for now.

[bretski]

Here's what the opening looks like after a night in the kitchen freezer:



Is the opening large enough?

[vwlover77]

Looks about right!

[bretski]

Thanks, Don. There's no spec anywhere for how large the opening should actually be when cold. I'm moving on to the elbow today. I suppose that the cracks that were developing could give just enough vacuum leak to cause a problem.

Durocshark re-plumbed his, I remember, using some copper tubing. I'm probably going to try something similar. The elbows available today are absolute garbage, German or otherwise.

[vwlover77]

They were set at the factory. That's why the nut has sealing paint on it.

I replumbed my elbow using rubber heater hose and a nylon barbed-end 90 degree plumbing elbow from Home Depot.

[Ritter]

That looks good to me. More here if it helps:
viewforum.php?f=42&sid=c719f436c74b80d2ae51ca5539b4f8ba