i have 1993 bonn ssei just put new motor gm when motor is hot at highway speed
you kick it down will no tgo over 3 - 3200 rpm you also get what feels like a miss
thunk thunk feel every thing has benn tested new plugs wires most sensors could the super chager cause any of these car had 335000 kil supercharger seems fine but i would like to recon if i can find kit in canada

That sounds a little like what my Park Ave was doing. You mihgt try getting your coils and Ignition Control Module checked.

thanks for the info ihave changed both are new no diff

If by testing the ICM, you mean taking it in and having it tested at a store, forget it. Bad test good, and good test bad. It'* a no-win proposition.

Check your coils for starters using the procedure in Techinfo. If an ICM is bad, chances are you'll have a check engine light. But the PCM can't even see the coils.

How old is your catalytic converter? When mine was bad it felt like a bad miss when I was going WOT.

Ed

Thanks guys iwish this were the problem 1 no cat 2 new coils 3new ing modual4new maf sensor when engine cold has lots of power will red line but once i hit 180 it starts
but thanks for all the help i owe you guys

This may sound simple and stupid to you, but have you replaced you thermostat?

If you can get your hands on a set of coils from another 3800 swap those on. Go for a drive and see if your problem still arises when the engine temps increase. I have heard of coils OHMing out good but once heated up be the cause of rough idle or missing.


Ed

yes i have replaced it and no it does not sound stupid but thanks anyway i have
just found out i have 15 psi back presure in exhaust so anyone have good idea for
better sytem and thanks for all the ideas i will show picts asap car is currenty running
325 hp thanks to GM preformance mods and if i replace stock exhaust syst mabey more

325 hp?

So, is that new CAT a high flow CAT?