Off-idle stumble resulting from ported EGR

[Steve=Ravet%Prj=Eng%PCPD=Hou at bangate.compaq.com]

bohdan at uscbu.ih.att.com (Bohdan L Bodnar) Wrote:
| 
| 
|I've driven GM cars before (with and without computer-controlled EGR) and 
|never experienced this problem.  A hesitation like this suggests other 
problems
| such as:
| 
| 1). incorrect TPS setting/erratic TPS operation at this point
| 2). slightly clogged injectors
| 3). incorrect ECT information being given to the computer
| 4). incorrect fuel pressure
| 
| I'm quite surprised that you're seeing these performance problems in so many
| different engine.

I've seen this exact problem in two '86 4x4 S-10 blazers (3.8 v6?) and an '88 
corsica (also 3.8 v6?).  I never thought it was related, but now I wonder.  
This probably belongs on rec.auto.tech, but since someone else brought it up, 
I thought I'd offer my piece.  Anyway, the symptom is hesitation just off 
idle.  Give it a little more throttle and it is cured, but it persists as long 
as the the throttle is held barely open.  It is a feature on the corsica 
(had the problem since new), may be a bug or feature on the blazers, since 
they were used by the time I drove them.

--steve