help! 1990 Chevy full size blazer?

I'll say no to your headgasket and raise you to fuel injection.You have tbi-throttle body injection.On the side of the tbi unit is a tps-throttle position sensor.The internal electronics may be loosing contact,and in turn your computer doesn't know where the throttle is.There are many other possibilities with electronics but I would start with checking powers and grounds,loose wires,terminals in the connectors.This system works on a 5 volt reference from the computer so one wire should have 5 volts,one is ground,and one is the signal to the computer.

To be straightforward i'm no longer a Chevy guy, nor am I regular alongside inclusive of your engine. yet through technique of truth it rather is a 1990 it of direction has gasoline injection (likely a throttle body gadget), and that i have were given by technique of no means seen a gasoline injected motor that operates on below 35 PSI, even on the oldest American TBI structures that began out interior the mid-1980's. favor that helps. through strategies, i'm exceedingly particular the lads above me are speaking about OIL stress, no longer gasoline stress.

sounds like its cutting out. How long into the drive is it? How many miles? Has it just gone into closed loop? Timing would be a problem that wouldnt be intermittent. My guess would be MAF sensor? You're best bet is to get a snapshot of your ecm at the moment it starts to act up. My guess is that you'll briefly see one of the sensors out of range.

Let's say its the head gasket.