Did you try UNPLUGGING the O2 sensor? If it's OK it shouldn't make any difference. The next question is this - is the CAT PLUGGED, this *will* kill a motor after a few minutes of running, and severely hamper RPMs. Has the CAT rattled? Or made any weird noises loose being loose?

Good luck - beware the dealer..

AB

William Grace wrote:

I'm stuck in Pueblo, CO with my 85 Westy and my incredibly good spirited and encouraging partner, Kerri. I would appreciate any ideas before I visit the VW dealer in the morning.
Background: I just bought the Westy in Tennessee, and am driving it back to Seattle. It ran great from Tennessee to Pueblo, and upon arriving in Pueblo today, and driving in stop and go traffic for about 15 minutes in 97 degree heat, the symptoms started.
Symptom: The 85 Westy's (with manual trans) engine cuts out, hesitates, runs irregularly, and finally dies altogether when it gets hot. This progression takes about 30 seconds. While the symptoms are happening, I can kind of "feather" the throttle, and keep it running for a little longer - especially if I can get it up over 2000 RPM. Immediately after it dies, it cranks fine, but won't re-start. After letting it sit for about 15 minutes, it will start and run normally for about 5 minutes, then the symptoms start over again. I've repeated this process 5 times now, and it acts the same each time. The coolant temp gage reads normal (about mid-scale) all through this, but I'd guess the temp in the engine compartment was the highest it's been since I picked up the van.

Here's what I've done so far, and none of this has changed the symptoms at all: When I looked at the engine after it died the first time, the hose from the crankcase breather to the air intake boot (about 1 inch diameter hose) was sucked flat in the middle. It had lost all it's stiffness - heat? and was floppy. I replaced it with a nice stiff hose of just the right size from Auto Zone. Free too - it was a scrap. Thanks Auto Zone. It didn't do any good, though, still had the exact same symptoms. After that, I replaced the air filter, cap and rotor, plugs, plug wires, all of the little fabric coated vacuum lines, and fuel filter. The rotor was really bad looking - the center contact was broken off from the metal strip leading to the spinning rim piece. Must have been sparking across the little gap. And two of the plugs were loose. Anyway, that's all interesting, but none of it helped. I brought all those parts with me "just in case", and it's Sunday afternoon, so might as well put 'em in, huh? I also tried to replace the O2 sensor, but couldn't get the old one unscrewed. It is full of gas & oil level's fine.
Here's what I haven't done: Any real troubleshooting to isolate whether it is a fuel delivery problem or a spark problem. I guess I'm going to leave that for the dealer in the morning, but any thoughts on these symptoms would be greatly appreciated. Thanks.

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