Chevrolet Repair: s10 blazer hard to start when eng. is cold, mass airflow sensors, s10 blazer 4x4

Question
i have a 1994 s10 blazer 4x4 with a 4.3 vortex eng.milage is just over 100,000. when the eng is cold you have to turn it over a few times be for it will start, sometimes the only way to get it to start is to spray carb cleaner in to the intakeand then it will start right up and run good.as long as it does not sit for more than 5-6 hrs it starts and runs good. cap, rotor, wires, and plugs are less than a year old.i just replaced the fuel filter, coolent temp sensor. fuel pres. is good at about 55 psi. fuel pump relay seens to be workingand oil pres switch tested good. thanks for any advice you can give.

Answer
Hi Tim,
Sounds like you checked about everything.
There is a crank sensor that sends a signal to operate the fuel pump relay, and the injectors.
I wonder if the injectors are leaking a little, and letting the fuel drain back out of the lines. I would think a couple key on cycles would overcome that.
I have heard of mass airflow sensors getting dirty, but haven't seen it myself. But worth looking at.
They said they cleaned them with spray contact cleaner.

Good luck,
Van