I have a 98 Blazer Mark III. Can't find out anything about the Mark III package.Just wondering what all is different about a Mark III

 

I've never heard of one. I wonder if it's some kind of dealer-added "custom" package. Do you have some pictures (interior and exterior)?

 

Looking foward to seeing and hearing more about this

 

So everything was working perfectly I recently changed the fuel pump the fuel spider the fuel filter plugs and wires and just the other day the truck turns off after it started to sputter. At first I could turn the key and give it gas and turn it back on just enough to get home but now after about 15 minutes it stalls and that’s it I have checked the EGR and it seems like the voltage is properly working like I said prior I have changed the fuel pump the fuel spider the fuel filter plugs and wires. I can’t figure out what’s happening with this truck everything is perfect and about 15 or 20 minutes later it’ll do a little sputter and then turn off

 

The first thing I would do is put a fuel pressure gauge on it and drive it to see if it loses fuel pressure when it starts sputtering. You need to determine what is failing (fuel, spark) so you have a direction to go.

 

I have tried testing the fuel pressure the problem is when the car starts to stall it also loses voltage which in return reduces the amount of pressure because the fuel pump turns off . So the fuel pump pressure falls as the car stalls every time the fuel pump is brand new the fuel filter is brand new the fuel spider is brand new and the fuel pressure regulator is brand new

 

The issue ended up being my alternator. It would not always do the same thing and every time the car would start perfectly fine and running for a period of time but then start to malfunction. what I ended up doing is checking voltage on the brown wire that goes to the bottom of the alternator from the gauge cluster. The brown wire did have voltage which meant it was telling the alternator to turn on although I had no voltage coming off the large post on the back of the alternator. After finding no voltage from the back of the alternator I took it to a local parts store and had them bench tested where I found out it was bad. After replacing the alternator everything is working perfectly fine

 

Glad to hear you got it figured out. We still want to see some pictures of this Mark III unicorn.