Although I have a 3rd gen (`85 IROC) this is actually about my `86 Monte daily driver. It`s got a fresh stock 4.3 TBI in it that`s got a few problems. First,on startup the RPMs climb to 2K and stay there for about 1 1/2mins. before they slowly fall to 1K,then down to about 600 where I have the idle set. It only does this when it`s cold (the engine not the weather). I checked the IAC count and it climbs then falls with the RPMs. I cleaned the IAC and passages and set it according to the book and it still does it. The other problem is performance oriented. I don`t expect it to be a rocket but it`s REALLY REALLY SLOW right off the line (say 0-10mph and especially 0-5mph). It makes no difference if I use part or full throttle in this range. After 10mph it picks up great (actually it almost surges forward briefly like a mini turbo coming it) and therafter runs great. The car`s basically stock with shorty headers and stock exhaust (for now). I have `87 442 exhaust,dual snorkle aircleaner,TBI spacers (2 1/2"plates,I dunno if I should use one or both) and I have 2 extra gaskets for the injector base. I`m basically waiting for better weather to swap the new parts on. I tried the car with the exhaust off in front of the cat and it was just as sluggish. It seems even worse after I drive for a long while. It feels a lot like starting out in 2nd gear but it`s not. The car has 2.41 gears (yes I know,yuck!) but with the 200R4`s lowish 1st gear it should be like 2.73s. Still not great but I`ve driven 3.8 2bbl cars with 2.73s that were quicker off the line. Any ideas on how to fix this stuff....besides a 350 TBI and 3.42s. Marcus

 

Dont worry about the high idling at startup, thats what your car does to warm up faster. mine does the same exact thing.

 

Make sure that your distributor has not come lose. mine did that and it was really slugish off the line so i bumped up the timing and tightend down and now it' come's hard off the line

 

Checked that already too. I actually have it advanced farther than stock to get it running even this good. It pings just a little accelerating hard up big hills and such but it`s fine 99% of the time. Marcus

 

Geeze, I thought the TBI gurus here would be able to shed some light on this thing...guess I`m on my own.

 

Go to a transmission shop and have them take it for a ride. You're transmission may be starting to go. Tell them what it's doing and go for a ride to show. Make sure it's a good shop, and not just someone who can replace parts.