My brother is working on his 1988 k1500, cracked head, he put it back together, no fuel (pump not running) there is a plug coming out of wiring harness behind distributor, cannot see or feel where it plugs in, jump plug with paper clip fuel pump runs. cannot see/feel where this goes. any suggestions?

fuel pump , fuel pump relay on fire wall, fuel filter, may all need replaced, pump in tank, inspect all wiring in this circuit, especially all grounds,, grounds get overlooked & that is sometimes the problem. I have a 1988 gmc 2500, I 'm talking from experience. can you hear if fuel pump runs for 2 seconds, when you turn key on ? if not, ground problem or pump problem. relay has a fuse in it, check that. check all fuses. NOW, spark ! coil ? plug wires ? distributor cap & rotor ? replace them if you haven't !!!!!!!!!! get to work, see how you do ! good luck !

I would check the fuel pump relay first. You should have some fuel pressure in the lines when you turn the key on. The relay is powered for 3 seconds to boost pressure until the engine starts.
The relay may not be working or the check valve in the pump may be letting fuel back into the tank which would cause the pressure to drop to zero when the engine is off. You should have at least 15psi with a TBI system and 35psi with MFI.

Is the filter on the firewall? If it is , there is a valve at the bottom of the fuel filter that can come loose. If this is not the problem then the rubbers on the back of the filter are probably bad. Replace filter. Any auto parts store will carry these filters. When you put the new one on ( they just push on ) unplug purple wire on top front of engine. Loosen valve on fuel filter and crank engine in short bursts until fuel comes out of filter. Tighten valve, plug purple wire back in and start engine.
Good luck

Well if he caused a short in the electrical system it could be the eec relay it is located on the passenger side under the hood on the fenderwell. Some are marked with what they do there can be 3-4 relays on it, the relays look like a small box with a connector at the bottom, and quite a few wires coming out. the one for the eec relay should be in the middle it was on my fathers 88 bronco 2. the fuel pump relay is the same thing, there cheap to buy and can find them at the parts store they are known for failure, just replace it..

looking in the spark plug holes is not the way to do it.you wont see nothing from that first off if theres no plugs the engine will get its intake stroke air from the plug hole so you wont see any fuel
if you want a quick check to see if its a fuel problem have your brother crank it while you shoot a little starting fluid down the throttle body
if it starts or trys to start then fuel is were to look
i dought the injecters went bad.out of gas? think about it it ran before you took it apart now it does not so i would recheck all the wires to the sensors make sure you reconnected all the ground wires. check every fuse in the fuse box or boxes.hold the throttle open a little bit the battery was unplugged so the computer has been reset.

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528008f3ce

computer wiring could be bad /computer bad..should be spitting codes....tired motor / internal damage ? timing chain/gear set up improper?

Listen for the pump to see if it is actually pumping, your electrical might be hooked up improperly. Check to make sure the pump is installed correctly, not back wards. check to see that there are no pinched hoses, is it an electrical pump or vacuum pump?

dump where? gas tank ..carb?..look for cracked fuel lines from tank to engine/fuel pump

Have you confirmed fuel pressure at rail?