I bought my blazer used a few weeks ago and happen to run into a guy the same day that has a blazer with over 350K miles on it. He told me that the '96-'99 Blazers with the 4.3L have a flaw in the delivery of the fuel in the injection system and that if I wanted the engine to run longer and improve mpg and performance I needed to upgrade the ???? I can't for the life of me remember what part he said to upgrade. He told me it would probably run $400 and it improved the way the fuel was distributed to the injectors and made the whole system more effecient. I tried to track him down again but I can't find him. You guys know what he was getting at?

I've looked at a bunch of replacement parts, but I can't seem to find anything that is improved/different from what the vehicle already has on it. My vague memory of our meeting tells me that it had to do with the fuel being pumped and distributed from one location right now, and the upgrade being the fuel is pumped from six locations. I know that sounds stupid but that is as much as I can recall.

Any help is greatly appreciated.

Kellen

Here is a GM Technical Service Bulletin that might be what you're looking for. It involves a retrofit from the newer CSFI system back to the older style CMFI system.
http://members.shaw.ca/betterthanyoutoo/Sticking%20Poppet.htm
This is not a "Miracle Repair" by any stretch of the imagination, like your friend has implied. It simply reverts back to older technology. Although in certain instances, it does cure the problem.