Had a slight rattle coming from under the Burb lately but assumed it was the exhaust (seriously sounds like it). Comes and goes at particular rev's.
Took the kids on a trip to another town today...and whilst accelerating to 100kph....smoothly, but reasonably firm....something suddenly changed.
Started sounding/feeling like I'm running on less than 8 cylinders. Nothing else changed.
No smoke, all pressures good. Checked all fluids...all good.
Nothing 'bad' looking or smelling under the bonnet.
Don't have a plug socket handy to check the plugs.
Any thoughts?
I'm 7hrs drive from home.....and should make it home ok on Saturday morning....but I'm a bit concerned.

Internally damaged cat?

D I Z Z Y cap on it's way out?

What's a bonnet? j/k

Since you're away from town you're also away from known good gas stations. So, bad tank of gas clogging the filter? A defective cat also sounds likely as well, from the odd noises you heard before it happened. For that, feel the exhaust, should come in puffs. If the cat or muffler have failed, then it may/should feel smooth, not pulsy. Does it do it all the time now, only before/after full warmup, ect?

EDIT - Just read your AC compressor problem, it's also possible that the compressor is siezing on you, which will put a real drag on. And, I've had an alternator crap out that put enough of a load on the engine (4.3L) that it would actually kill the engine. On that one, it popped the shaft bearings and the shaft locked. Since it's summer down there, you likely had the AC compressor on, does it do this with the AC off?

thanks guys. Only cats are the ones happy to see us as we just walked in. Made the 7hr drive home with ALOT of backfiring. When cruising at low load, it was going very lean (watching the wideband gauge). So.....I'm not sure what to look at yet.
When it's a bit cooler I'll change out the fuel filter for starters.
I did notice my fuel pressure was quite a bit higher than usual? Regulator? I sometimes smell fuel....which I wasn't before.

When was the last time you changed the cap? I just recently worked on mine because of an engine miss. After less than 6 months, the ebay cap's electrodes where severely corroded. I cleaned them up with a dremel wire brush wheel and it was good to go.

Yeah.....haven't changed it. List of things to do is:
Change fuel filter
Change plugs
Check cap and rotor....for starters.

did you happen to kick anything up into your gas tank?

i ran over a carpet in mine and the fuel pressure went through the roof - the bottom of the tank actually prevented fuel return (it was pushed up against it).

looked and sounded like this
http://www.streetfire.net/video/97-chevy-rich-rough-idle_83975.htm

the only time i had it backfire was when i broke my distributor......the brand spanking new one that had less than 2 miles on it.........

once i fixed that, this problem cropped up
http://www.streetfire.net/video/97-chevy-305-zz4-cam-idle-surge-fluctuating-af_86322.htm

did u drive by tbi™ on the way home

Change your fuel filter too. When Mine pluged it backfired had no throttle response. Check your cap for carbon tracking. There was a truck came in to the shop I worked at. It wouldn't start. I checked the codes. Can't remember what they were. My boss had me change the crank sensor. That wasn't it. I took the cap off to make sure the distributor turned. I noticed the carbon tracking. I changed cap and rotor plus plugs. Started right up. Run fine after that. Do one thing at a time. If the filter hasn't been changed in awhile. Change it anyway. I change mine every two years.

Yeah jeff....it kinda idles rough...surges. When idling 'in gear' with foot on the brake, it tries to move.
According to my AFR gauge it's idling lean.
Chev 97....first thing will be the fuel filter....hasn't been done in a while. I'll pull the reg and take a look at that also.
Yep....one thing at a time.
I plan on dropping the tank (last) and changing the pump also (I have a Racetronix Walbro to install).

Pro.....tbi™ is extremely rare 'downunder'....but ya never know!

Howard, be careful with letting it run lean too long being 7 hrs away from home and no access to a welder..... Those Cats will fail quickly being too lean like that. Fuel filter would be easiest/cheapest to change for quickest results.

No cats man.
Only cats I have are a couple that go meow!

Well....changed the fuel filter. No different. Pulled the reg and checked the little screen/filter - clean.
Next will be to check the distributor and components.
I'll have to wait a week. Doctors have taken me out of work for a week whilst they run the gammut of tests on me. Been getting headaches and stuff for a week or so.

When's the last time you slept? loll

I don't sleep much my self but I compensate with healty eating habits (boring!!!). Haven't had a headache for about a year now...

Used to be every week.

Been getting plenty of sleep lately but wake up every morning feeling badly hungover.
Doc's today showed my blood pressure was a bit high.
I get headaches from time to time, probably from lack of sleep....but this is different.
Doc reckons a bit of stress maybe. Dunno..we'll see.

OK....healthwise....all tests seem to be OK....so in general....I'm good to go again.

Burbwise....changed the plugs and distributor out today. Plugs looked 'tired' but def not worn out.
distributor....cap terminals had some serious corrosion and the centre pickup on the rotor was extremely worn.
Good news is....this is one of those cheap Al units and the gear looked almost new.
One thing I noticed was....when pushing down on the rotor and then turning it, it felt to be binding up quite a bit.
One of the guys at work is going to pull it open tomorrow and replace the berings/bushes.
I stuck in a brand new stock item with new cap and rotor. Thought I had it all lined up but it wouldn't start (tried to).
Moved it one tooth, fired it up and it idled fine.
AFR was pretty much dead on 14.7 and no bad noises.
I'm not ntirely convinced everything is right yet....but I'll whack the laptop on it on Tuesday arvo and check the CMP retard.
It rev's hard agaoin.....so hopefully all is OK.