I recently purchased a 1998 GMC 2500 cargo van. It has 202,000 miles vin 1GTFG25MOW1074776. I think with the M in the vin means its a 5.0 plus the 3/4 ton van has 6 lug wheels. The van needs just a little shot of starting fluid to get started when cold. It idols fine and will stay running. If you try to give it gas it stalls out or will barely pull itself. The man I bought it from said he replaced the fuel pump and filter. He said it needed new fuel regulator. Since they are not complex objects do you think its the regulator or do I need new injectors. How hard are they to change on a van, and should I replace anything else why in their. Thanks for your time.