Been having issues with my '98 s10 4.3L V6 2wd. Sometimes when I go to start my truck I will turn the key and the engine will turn over and start kinda weakly and then stutter and die a few seconds later. It doesn't happen all the time..it seems to mostly happen after the truck has been sitting off for a couple hours. If I start it and immediately rev the gas before it dies the truck will stay running but I have to gently ease off the gas pedal or it will die again(like a 5 second rev). If I let off the gas too quickly the dash lights will go a little dim and it will stutter and die. After I do that the truck runs perfectly fine no other issues. I usually get it running on the first try.

I've also noticed-In the morning I'll go out and do this and then go back inside to let the truck warm up since it's been about 20-30°F here. When I go to get back in the truck after about 10 minutes the temp gauge has not moved at all and the heat is still blowing lukewarm to cool air but the oil pressure gauge has risen a little more than the halfway point. After I start driving the temp gauge starts rising to where it should be, the oil pressure evens out and the heat starts blowing hot. I have no idea what could be causing these issues and I want to know what I can do to fix it or troubleshoot and narrow down what is causing it. All help is greatly appreciated. Thanks!

 

Does it only do this on really cold days? I would say that your thermostat may need replacing as well as your fuel pump. The thermostat is cheap to buy and easy to replace, so I would do that. sounds like the check valve in your fuel pump is bad and I would check your fuel pressure at start up. Don't do it after it has been running for a while as the pressure will probably be good at that time.

 

the fuel pump has a high pitched whining/buzzing noise. Normal?

 

No it is not normal. You should change it before it fails.