Take a look in tech info. There is a write up. You can also do a search on this forum.

I know that this is a different car but i have a 95 ssei, My other car is a 97 Chrysler LHS, mine did the same thing and it turned out to be the intake gasket and the MAP sensor. Would be fine at driving speeds but when it got hot it wouldnt idle. Just a suggestion maybe im wrong.

Thanks for the suggestion. I plan on doing the LIM even though I don't think my generation has the same defect as the 3800 II with it.

Also how did you know your MAP was bad? Or did you just end up replacing it without knowing it was bad...

My generation is series I also but the LIM gasket was due for a replacement. We do not have the stove pipe issue but that just means that our original LIM gasket should not need replacement as soon. There is still a very high probability that yours is due for a replacement and since you plan to replace your supercharger coupler anyway now is the time to do it. My engine is better than ever. No external leaks, smooth idle, lots of pickup. I will be doing the same thing to my Park Avenue in the spring.

Thanks Crece. Quick question, whats your vacuum measure at the intake manifold? Mine is around 15 and I'm wondering if that is a bit low...

Sorry, can't help you there, I haven't measured my intake manifold vacuum.

Ok I did the SC coupler this weekend along with gaskets etc and new plugs. It runs about 50% better I would say- still not 100% tho.

So I couldn't get the LIM off the block - apparently with my year you have to also remove the Alt bracket along with misc heater pipes etc. Well I couldnt' get the heater pipes or the bracket off and the LIM wouldn't come up. So I had to put her back together without doing the LIM gaskets...

If anyway has any suggestion on how to get the LIM off that would be great.

Sorry to hear about your setback. The 92 is a little different from the 95. Maybe someone else can shed light on the subject. In the mean time make sure you take a look at this excellent thread by Danthurs. https://www.gmforum.com/t278911/ Also, the paperback Chiltons manual # 28200 has instructions that are pretty straightforward and covers the 1986-1999 Bonneville. Also, Autozone has online repair manuals. Just go to the website, create a login ID and read the instructions. I had to remove the alternator but not the bracket however I see where you do have to remove the bracket and heater pipes. Why were you not able to remove those? Were the bolts too tight? If so try PB Blaster, let it sit a few days. Was it too difficult to get to? Wrong tools? What?

Thanks Crece - I do have the FSM for my year but unfortunately it was not very helpful except to say that I need to remove the bracket and heater pipes.

Well its just that I couldn't seem to get to all the bolts to get the bracket off and the metel pipes had a piece welded to the bolt. Kind of hard to describe, but I just couldn't pull the metel pipes out of the LIM - hence not being able to get to the bracket bolts.

If I'd spent a bit more time working on it I probably would have figured it out eventually - I was running out of daylight and wanted to get the car back together.

Good news tho - I don't have to remove the SC separately apparently I can remove the LIM + sc together once I finally get that bracket out the way.

It'* good that you don't have to take the SC off separately again and now you have a good idea of what to expect. I would suggest at this point that you start a new thread addressing your specific year and problem, i.e. you need help figuring out how to get the alt bracket off, heater pipes out, or however you can word it best. That way you will probably get more attention to that specific problem. You may want to give a little background but only about that issue and not so much about the miss. I'm sure there are those who have replaced the LIM on that particular year.