2001 Blazer LT wont start

[mat300z]

ok, so on the way home from the store the Blazer just cut off on me. There was no hint of trouble and no codes stored in the computer. The rpms just went to zero. I tuned it up about 2 months ago...new plugs, wires, distributor cap, rotor, airfilter. Then about a month ago I did the lower and upper intake gaskets..(ran like a champ)...then last week I did the starter (solenoid crapped out) ran good till saturday...Now it wont start at all...although it cranks over and over...I did a fuel pressure check and it showed 60 psi...but I figured since the fuel guage has been acting erratic may as well change the pump...so I put a new pump in yesterday and crank positioning sensor but still wont start. I have good spark at the coil and plugs and 62 psi of fuel pressure and holds 55psi for atleast an hour, so it puzzles me why it wont start. The engine runs strong even with 150,000 miles on it. Seems like it may be an injector problem, does anybody know how to check this or have any other Ideas. The truck is a 4.3 vortech "W" any help on what to do next would be appreciated.

[MT-2500]

You need 60/66 lbs of fuel pressure.
65 on cold cranking.
Even a few lbs low will keep the injectors from squirting on a cold start?

Watch and check the fuel pressure while the engine is cranking.
Will it start with a shot of carb cleaner?
Have you rechecked for checked for good hot blue spark at all plugs?
Any security lights on?
Do you have plenty of gas in it or tryed adding 5 gallon?
Does fuel pump prime up on key on and run when cranking engine?

[mat300z]

Originally Posted by MT-2500

You need 60/66 lbs of fuel pressure.
65 on cold cranking.
Even a few lbs low will keep the injectors from squirting on a cold start?

Watch and check the fuel pressure while the engine is cranking.
Will it start with a shot of carb cleaner?
Have you rechecked for checked for good hot blue spark at all plugs?
Any security lights on?
Do you have plenty of gas in it or tryed adding 5 gallon?
Does fuel pump prime up on key on and run when cranking engine?

engine cranks with about 65 psi...
engine had good spark yesterday
no security lights on
tank has 10 gallons in it
fuel pump primes and pressurizes (new)

funny thing is when i put carb cleaner in the throttle body it didnt do anything so I checked the spark again at the coil and its dead??? It worked fine yesterday and the plugs were firing. ok so I am gonna go check on the ignition circuits and I'll keep you posted

[MT-2500]

Also check both side of all fuses for 12 volts.
Let us know how it goes.
MT

[mat300z]

Originally Posted by MT-2500

Also check both side of all fuses for 12 volts.
Let us know how it goes.
MT

The fuses all check out fine...I got the spark back by putting the old crank sensor back in place, the new one was defective...The blazer acts like its out of time. I have good compression, spark and fuel...how do I check the injectors to see if its a problem with the spider?

[MT-2500]

To see if it is a fuel delivery problem try the carb spray again and see if it will start on it.

To check injectors check for 12 volts on positive side and for injector pulse.

Pull spark plugs and see if they are wet.
If you have been craking engine with no spark it could be flooded.