Im a mechanic with a 99 Blazer,it idles fine but when you step on the gasit spits, sputters, and backfires, it acts like its starving for fuel. Ive recently installed a new pump and filter, and tune up,checked fuel pressure its 55-60 psi, No check engine light, Had a scan tool hooked to it on data-stream, all sensors within normal range, Im starting to think its the computer...anyone have some ideas?

 

You've made sure that the passenger side valve cover vent is hooked up to the back of the intake 'hat' right... I have had this happen when I completely forgot about that hose.

 

I will check that today, and let u know

 

Yep the tube is hooked up, Just acts like the injectors quit firing when you stepp on the gas, it bogs out and almost dies the starts poping and sputtering like its starving for fuel, Ive checked spark when this happens and its fine, At Idle its fine, Also Ive checked fuel flow and seems to be more than enough. It seems like a bad TPS but it checks out fine too.
still thinking computer, can you get a computer from the junkyard and slap it on, or do you have to get it reprogramed first? I have a 2000 s-10 thinking about swaping out the computer. acording to the interchange book there the same.

 

Yes, you can grab a PCM from a junker, just make sure that it is from a '98-'00. I believe it was mid '01 when they switched over to a different EGR system.

 

Thanks for the help,
It was the mass air flow sensor, unplugged it while it was running and she sprung to life,yankedone off the junkyard s-10, runs like atop now,feel like an idiot, must have overlooked that when i had the scan tool hooked up.