I've had a freaky thing just start to happen. I get home from work and about 15 min later go jump in the car to take off. I start up the ole hotrod and sh'es running rough- really rough- barely running, missing- throttle response of zero- chugging and coughing- I'm thinking oh holy shipola- then it smooths out and runs normal.
Now normally I would think-vapor lock- but I've never experienced this before and I've had it long enough to know every little noise and quirk that makes up her personality...... This is a new one. It'* done it several times in the last week. I ran some fuel system cleaner through it and put in a tank of high test- it'* still doing it. This sure has all the makings of vapor lock to me but I'm probably wrong- but why didn't it do it when it was 100deg out last summer? I even took that plastic cover off the supercharger- that was like a heat blanket imo so took it off.

Any ideas?

Uh..your sentance about .. "gave her a tank of hitest" kinda scared me. Your car runs on premium, premium only...and should ... yup only be filled with premo fuel. Otherwise you risk holes in pistons and other majorly bad things that rain on anyone'* sunny day.

Anyhow.. If it'* typically at startup, I'd pull the throttle body and clean it. Most likely the IAC isn't switching from hot running to slightly cooled down idle control all that well and is gunked up. At least...that'* my first thought.

Yeah, I don't always get the high test- I put a tank of regular in once every 4 maybe. Some places around here are only carrying regular anymore, at least in your little farm towns. When I said I put high test in it, I meant the really high test- ultra- no, I don't buy that hardly ever. Once in a blue moon I might treat it to 94. Right now $50 for a fill up.

I'm not sure what "high test" is. Nor do I know what you are referring to by "ultra". I do know though, that you should always run 93 octane fuel (Premium). Like Bill said, you are subjecting your car to the possibility of serious damage by running anything less than 93 octane. If you do have to run a lower octane, you should stay off the throttle, and only put in enough to get you to a gas station that has Premium 93 octane that you can fill up with.

Tom...in some states 91 and 92 are the highest octanes available.

premium is 91 0r higher but 92-94 is best for out engines. i have seen the fallout of running 87 in a SSEi not pretty

Understood, but if I remember correctly that is how it is phrased in the owners manual. From that you can infer that while 91-92 is much better than 87, by running less than 93 octane, you should be more careful. If 91-92 is all that is available to you, just be aware that your chances of pre-detonation are higher than if you are running 93 and you should drive accordingly, especially since the 2000+ bonnevilles are already prone to have KR.

i had the same problem when i lived in west texas with the whole gas stations only carring reg. unleaded i just bought a case of octane booster and put it in every time i had to fill up with reg. it help a little bit

I have never heard pinging one time- even when 'm hammering on it- which is rare. It'* always sounded fantastic with not a blip.

Ultra- Sunoco Ultra 94- highest available not counting True Blue (105?)

Well- I better post this again here-

This is kind of an update on my studdering puking running at idle deal from the last 10 days. Now first off- I'm running 93 octane! so that'* settled.
Yesterday- I'm in city traffic 30-40 stop and go type traffic. I feel the car almost go neutral- I look at the gauges and tach is bouncing up and down- it'* trying to die on me just like my idle issue in previous thread. I've been thinking it'* like a vapor lock situation but still not sure. The shop got my car done friday doing all the manifold gaskets so that was kind of priority. It has NEVER as much as sneeze while running/driving- only this idle thing.
So it did it a few times, I was power breaking it at lights afraid it would die on me- can't be having that in crowded traffic- especially when I'm staring over at a Prius thinking to myself that I'm glad I still got my stones.
I'm going to try the fuel filter and cleaning out whatever on the intake side today. She'* starting to scare me a little though- This is a relationship based on trust and faith- The ground is shaking.
If you have any ideas please share.

btw- looked in the owners manual-91 octane 87 if you have to