92 blazer fueling issues

[KFeez]

My brother in law picked up a 1992 blazer with 4.3 4x4, and it ran crappy. The previous owner told him he replaced the fuel pump with one from a vortec motor, and that it was running way to rich. We took off the intake and could see the injectors spraying way too much, so we replaced the fuel pump with a new, correct one. We also replaced plugs and wires, distributor cap and rotor, and a egr line and valve prior to the fuel pump while it was still running rich. Now I can hear the fuel pump whine as I turn the key, but when it cranks the injectors will not spray, they will only drip steadily. This causes it to not start or run, unless I spray fuel directly in, which shuts off as soon as I stop spraying. The fuel line going into the throttle body has plenty of pressure once removed while the fuel pump is priming. I didn't find any blown fuses under the driver's side dash. Why won't the injectors spray correctly?

[MT-2500]

Originally Posted by KFeez

My brother in law picked up a 1992 blazer with 4.3 4x4, and it ran crappy. The previous owner told him he replaced the fuel pump with one from a vortec motor, and that it was running way to rich. We took off the intake and could see the injectors spraying way too much, so we replaced the fuel pump with a new, correct one. We also replaced plugs and wires, distributor cap and rotor, and a egr line and valve prior to the fuel pump while it was still running rich. Now I can hear the fuel pump whine as I turn the key, but when it cranks the injectors will not spray, they will only drip steadily. This causes it to not start or run, unless I spray fuel directly in, which shuts off as soon as I stop spraying. The fuel line going into the throttle body has plenty of pressure once removed while the fuel pump is priming. I didn't find any blown fuses under the driver's side dash. Why won't the injectors spray correctly?

Is this a TBI injection with the two injectors in TBI?
If so how did you remove intake and look at injectors or did you just pull air cleaner?

Does injectors have 12 volts to one side of them?
How much dripping are they doing?

If a high pressure fuel pump was installed on it it may have blowed the fuel pressure regulator.

If 12 volts to one side of injectors and injector pulse when cranking and 9-13 lbs fuel pressure the injectors should squirt.
Make sure you have 12 volts to one side and injector pulse cranking and proper fuel pressure.
Post back what you find there.

[KFeez]

Yes, TBI engine. Injectors are only getting 3.4 volts peak while cranking to start, even with battery charger attached.

[MT-2500]

Originally Posted by KFeez

Yes, TBI engine. Injectors are only getting 3.4 volts peak while cranking to start, even with battery charger attached.

Be sure you are checking voltage on injector positive side.
Key on and engine cranking they need 12/13.6 volts to them and a good injector pulse when cranking engine.

If only 3.4 volts to them key on or engine crankig check injector fuse for 12 volts both sides and then trace wiring from fuse to injectors for voltage lose .
If you can not find where voltage lose is run a fused jumper { hot key on and engine cranking and running } to injectors positive side.
Good Luck and.
Let us know how it goes and what you find.

[KFeez]

I have been tinkering with the blazer on and off and still can not get it to run. I couldn't find any blown fuses. I replaced the fuel pressure regulator with no results. It is getting plenty of fuel pressure to the injectors, they just will not spray enough, it just dribbles out of the injectors equally on both sides.

[MT-2500]

Originally Posted by KFeez

I have been tinkering with the blazer on and off and still can not get it to run. I couldn't find any blown fuses. I replaced the fuel pressure regulator with no results. It is getting plenty of fuel pressure to the injectors, they just will not spray enough, it just dribbles out of the injectors equally on both sides.

Tinkering with if may not fix it.
Only proper testing will get the job done.

As in upper post.
Fuel pressure has to be 9-13lbs.
Is it?

You have to have 12 volts to injector positive side.

IS IT 12 volts ?

IF NOT FIX THAT.

If 12 volts to positive get a injector pulse testing noid light and check for injector pulse.

Remember.
The big 3 is.
1-fuel pressure up to par 9-13 lbs
2- 12 volts to positive side of injector.
3- injector pulse to negitive side of injector.

UNTILL YOU HAVE ALL 3 OF THE BIG 3 IT WILL NOT START OT RUN.