I have just gotten my 1st Blazer and it is 1991 S10 4WD with the 4.3 engine, 135K miles. Several times it has acted like it was running out of gas but I was able to get it home driving very slowly. The next day it would start and act ok. This has happened 3 times. I replaced the fuel filter and replaced the fuel line but the problem still occurred after doing this. I have checked the OBD codes and I only get the normal "12". I also notice something going on with my oil pressure gauge – ordinarily it carries about 60 psi but when the engine goes to low idle after warming up, the gauge goes to 80 psi. It seems that the pressure should go to less than 60 psi. Possibly this is related to the other problem. I hope someone can offer some help with this and any help will be appreciated.

 

How's the battery & alternator? Check that first - and if that's all good, then check the fuel pressure. Could be the pump getting ready to take a dump.

I wouldn't be too concerned with the oil pressure, as long as it's reading something. They are notoriously inaccurate.