Jivermo wrote:I don't see any catalytic converter here at all. What is inside the heater boxes? In a system like this, where would there likely be a blockage-if there is indeed one? Exhaust system work is at the far bottom of what I like to do on my bus...
https://picasaweb.google.com/1013662011 ... uary152013
You couldn't have uploaded a smaller picture to look at? heh
No CAT on that setup at the moment, you're right. I doubt anything is blocked and why are you taking it to an oldschool VW mechanic? You already know this bus better than that guy, who is most likely (as they all are) to be more familiar with a carb'd T1 engine than a FI Type4.
If you had an obstruction in the exhaust you'd feel it before driving for 20 minutes straight. There's likely nothing wrong with your current exhaust system, but take better pictures or carefully inspect yourself the EGR connection. Is the crossover pipe still connected to the EGR valve? is the EGR pipe connected to the actual exhaust system, or has that port been welded closed? (if so, has the connection on the intake plenum where the EGR valve connects also closed off so it isn't sucking in unmetered air?)
You need to start finding out what you can and cannot replicate to. Is it always something that happens after extended warmup periods? or can it happen (still, now that have been driving it more) as soon as you start it up and try to take it for a spin?
Some random things that have bitten me in the past, and worth spending a minute checking - how is the EEC valve on the airbox? If it's bad you should plug it for now until you fix it. Easy to test - just put a hose on it and suck to see if it holds vacuum. more here on that.
Take a look at the AFM itself. Blow out any crud inside it. How does the track look that the wiper runs on? is it wearing through in places?
