Hey guys! Before I start over-analizing the fixes I was hoping for some suggestions. I want to keep the 86 running until the winter, the cat convertor was rattling so bad that we replaced it with a test pipe for now. I have a good friend that owns a muffler shop and he put the cat in only 7 months ago...he said that the reason the cat burnt out was that it was way too rich. Ok so where do I start...the plug wires are old, the injector seals are old I haven't cleaned the throttle body or nothing (the shame of it all ;) ) I changed the t-belt last year and it has always had a rough idle ever since the last belt broke, I have checked and rechecked the timing (cam and ignition) and have replaced both pumps over the last 2 years. Can somebody suggest a good starting point? Thanks in advance for you help and YES I will take better care of my project 79gt 242 when I get it on the road also...
Ray
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keep the R's up!

o2 sensor caused my cat problems. bought a cheapo at oxygensensors.com 3 years ago, so far, so good.
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1985 240 DL, 1989 245 DL

First place to start is the O2 sensor. Check the output voltage, should be greater than .7 volts hot. If it is less, then the ECU is getting a lean signal and enriching the mixture to compensate. Next would be the air mass meter.
If the car is running generally well when warm and not too much difference when cold to warm, the coolant temperature sensor could be OK. These get 'lazy', like the O2 sensor and can perform OK under all but hot runnning conditions when they give a cold signal which enrichens the mixtuire, which cloggs up the cat
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'89 245 Sportwagon, '04 V70 2.5T Sportwagon

I'd look for a bad temp sensor, or broken wire/bad harness to the temp sensor. This would make it run very rich all the time.
Another possibility is a bad fuel pressure regulator- if the idle changes when you disconnect the vacuum hose, however it's probably OK. A fuel pressure test would confirm this, but it can often cost as much to have a shop do the test as it does for a new regulator... you decide there.
The temp sensor is not expensive and is definitely a good place to start diagnostics.
The cat runs about $125 from various online sources. You don't have to spend $500 for the Volvo one.
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Rob Bareiss, New London CT ::: '87 244DL/M47- 230K, 88 744GLE- 220K, 82 245T-181K Also responsible for the care and feeding of: 88 745GLE, 231K, 87 244DL, 239K, 94 855GLT 189K