What are if any tell tale signs of a fuel pump going bad? It seams like I have to crank for 5 seconds maybe longer before it starts.

 

Scew a real fuel pressure tester onto the Schrader valve and bleed the air out of the hose. Note running fuel pressure should be somewhere in the 50's. Then shut off engine and let it sit for overnight. Turn key on but don't start - pressure should quickly rise into in the 50#s and then shut off after 2 sec. At that point it should hold pressure for several minutes at least. If not follow sticky at top of 2nd gen forum about testing fuel pump pressure. Note that it does not require 60+ psi to deliver from modern later Blazer or replacement MPFI injectors. Most fuel pressure regs are now 58psi with engine shut off. Goes lower with vacuum from engine after it starts. The pressure requirements to run vary, depending on the design of the injection spider.

Another thing is to look at the fuel pressure when it is NOT starting - should be in the 50's.

It could be that the check valve in your pump is allowing the fuel to bleed back into the tank and has to start over again. This is most likely not happening if it passes the testing I outlined above. Or maybe you just need to wait for the 2-second pulse before trying to start as a diagnostic.

Good luck and best wishes for a succesful repair.

 

maf will do that too but lets start at fuel pump , you absolutely need a pressure tester and follow the specs strictly , these injuection units require much higher pressures than the average beast , key on pressure shop jump up 55-60 psi and hold, turn key off and time it for 10 minutes pressure should not drop more than 2psi a perfect seal will not drop at all , slow drop usually fuel pump is draining back to tank , sudden drop to 0 usually pressure regulator .

check out the fuel pressure test in the sticky ,it is right on point .

you can also try cycling the key on/off 2 or 3 times before cranking and see if that helps just let the pump prime each on/off -you should hear it ,if it starts -usually good sign of pump failing .