help me solve this mystery....

vehichle in question is 87 s-10 pick up 2WD, 4 cycinder, straight drive tranny, Ok, sometimes it cranks fine, other timkes it just spins over nothing, UNTILL you pour a little gas in the intake, after that it cranks fine, other times it cranks ok without pouring a little gas in the intake, it does this whether its the engine ie=s cold or warm, once it cranks it runs fine, then you can shut it off and after a few minutes it will crank ok without pouring gas in the intake, next time it may not, replaced injector after he broke it trying to take it off, so the injectors been replaced, we hear the fuel pump come on when he switches the ignition on, the local mechanic is still dun=mbfounded by the problem, cant figure it out yet. also he has replaced the fuel filter, i would like opinions to what the likely culprit is, im doing this on behalf of a fellow employee and we have something in common, we both drive s-10 s..... theres no check engine light and it doesnt cutoff ect going down the road. my best guess is maybe ther fuel pump, or the injector isnt getting energized at start up, he re0placed fuel pump relay and ignition switch also ......i have never seen a vehichle act quiet like this before
what is the cause?? I challenge you to solve this rittle and will let you know if it gets fixed, right now its in the shop,

We do not do riddles or guess work.
But we may be able tell you how or to help you fix it.
But first things first.
You need to check the basic.
Check for good hot blue spark to all plugs when cranking or no start.
Watch the injectors for a spray when cranking.
If no spray check that fuel pressure.
Post back what you find for more help.
MT

Fixed, he got it back other day and it was the Hall effect switch, never owned a vehichle with one of them so im not familiar on its workings ect...just glad he got it fixed, Thnxx anyways.

Fixed, he got it back other day and it was the Hall effect switch, never owned a vehichle with one of them so im not familiar on its workings ect...just glad he got it fixed, Thnxx anyways.

Thanks for posting back with the fix and how it went.
MT