My blazer has a pretty good surge at around 1500 rpm. It idles fine and runs fine a 2000 rpms. The dash light has a "service engine soon" and it is a code 32 if I counted right.and that code means a MAP sensor. So I replaced it and no change. I hate throwing parts at this rig and not fix the problem. Any ideas anyone? I can still drive it back and forth to work but the surge is making me a little nuts. Also if you put the Blazer in neutral and bring the rpms up slowly from idle it runs really rough until you hit the 2000 mark.
Like a really bad tune. thanks in advance

 

when i bought my 1990 i had a similar issue. seemed to do it around the same rpm when you were holding speed at about 1500. it would kinda jerk around like the engine was dropping out or misfiring. since i just got the truck i did plugs, cap and rotor with no change. to make a long story short after swapping out every part in the car i put a used computer in and it fixed the problem. i think the computer was dropping out the timing or something like that.

i was lucky enough to have a spare engine and tons of parts laying around to swap in all sorts of different parts til i found the problem. but the computer could be a possibility

 

I think I have it fixed. Turns out it was a bad EGR solenoid. Disco'ed the egr system and then plugged the vac leak at the throttle body and she ran like a top. Thanks for the help.