89' chev blazer stalls and won't start

This could have several problems. #1 Fuel pressure due freezing water in fuel lines add thermal aid or rubbing alcohol . If you have access to a pressure gauge there is a service fitting on fuel rail that you can test pressure while driving and see if the pressure is gone when car dies this could lead to fuel pump electrical or more restricted lines. #2 intermittent sensor failure Mopar uses 2 sensors to control spark and fuel lose one could lose spark lose the other lose injection with a scanner they call it C/C sync ok (cam/crank) if no then check for each parameters for display.# 3 relay controls ASD and FUEL pump for voltage drops.

Have the fuel pressure tested, running out of gas will destroy the fuel tank moumted fuel pump or cause it to run slow with the resulting loss of power.

with the key on engine off listen to fuel pump,if you can not hear the pump winning ,the pump is bad

if you can hear it,it might be working but create enough pressure
you can rent a fuel pressure gauge from auto store and check the fuel pressure

id not guess, there are 50+ reasons for misfire, yours is that.
the only way to diagnose a EFI problem is to use, tools .
got tools?
first tune it up, spark plugs, wire-set, cap, rotor and fuel filter & air filter. do the 60k tune up with a new timing belt if the belt slips all engine power drops, and misfires, and compression drops real low.
use a tool called a compression gauge.
1: the wrong gas cap will cause the fuel pump to stall. get a cap that is factory rated,with a real vacuum breaker.
2: low fuel pressure, use a , gauge .
3: injectors leaking or clogged, same gauge finds same failures.
there is no need to guess. and throw expensive parts, ever.
here is 43 ways to misfire here.
http://www.fixkick.com/misfiring.html

Have you checked Google I found this hopefully it's not your timing or it may be flooded but doubtful have you tried spraying starting fluid into the intake while cranking it

can see your are realy into this and your discription is exellance. But i have to tell you something that you don't want to hear Its your fuel pump its an 89 its over due . Chevy had problems with these pumps in the 90s not some much in the 80s they olny lasted 10 years at best unless you have already done if or know the history of the vehicle what you have discribed is not electrical but fuel issues the blinking mil light going up hill under load its a give away . You can try pulling some plugs if the look white instead of a tan color then its the fuel pump . And by the way the fuel relay on this vehicle is not the olny power supply to the pump there is a back up power supply to the pump through the oil pressure sending unit so even if the relay was bad the fuel pump would still get power through the sending unit it runs of fuse #9 for the ECM and fuse and splits one side relay and the other oil pressure sending unit. I have wireing schematics but there for mid 90s but the system is vary close to the same . And i kow what a pain it is to do the fuel pump good luck my frieind [email protected]

check your fuel pressure it should be 55-61 psi with key on engine off.It should have a fitting on the fuel rail to hook a gauge up to.If below specs replace pump.

Hello. The GMC Sierra has an electric fuel pump so you should ensure that its fuses and relays are working before checking it. You may need to clean your fuel pump or replace it if your gas tank is not empty, but your vehicle has difficulty getting fuel. The GMC Sierra comes in a variety of styles and trim levels that can affect the replacement fuel pump you choose.

It likely needs a fuel pump, hook up a fuel pressure gauge, it needs to be 11-13 psi

more than likely it's the gauge it sets in a circuit board and sometimes the contacts get worn and with vibration it voltage spikes it and then it fails. very seldom is it the sending unit in the tank. please rate this...thanks