1993 S-10 Blazer 4dr 4wd

I have owned my blazer since I bought it new in 1993. I have recently had some problems with the fuel system. I changed out the spider assembly last summer and it ran great for about 4 months then started acting up again. The last mechanic I sent it to put in another new spider and spliced some of the wiring in the fuel injection wiring harness. Two weeks ago, It died again. It did run enought for me to pull it in and out of the garage, but yesterday, it died for good. I have put two "spiders" in, and spent almost $2,000 for nothing. It is a great vehicle and I hate to get rid of it, but I am at a loss as to what to do. The fuel pump tests okay. My next step is to change out the wiring harness. One mechanic tested a voltage fluctuation in the voltage going to the spider assembly. Any suggestions? Thanks.