gm efi stumble

Hi; I have a 91 suburban 2wd with a 5.7 efi motor. Off idle, it chokes itself and you can smell fuel. If you take your foot off the throttle it clears up. This also happens on the road at part throttle.
It gets poor gas mileage. I have run the codes and get a 43. I changed the knock sensor, cleared the codes, but the 43 still comes up. It has new cap, rotor, wires, plugs, and timing @ 0. Compared to other 350s I have owned this one is a dog. Any ideas?
--
Posted at author's request, using http://www.AutoBoardz.com interface.
Articles individually verified to usenet standards.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Check engine vacuum at idle could be a restricted exhaust causing the engine to run rich, possibly a bad coolant temp sensor you can scan that and see if the sensor input to the ecm is the proper reading,.

----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.pronews.com The #1 Newsgroup Service in the World! >100,000 Newsgroups ---= - Total Privacy via Encryption =---
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.