2CarPros - Car Questions & Answers

1992 GMC Safari Repair Question


Topics covered: Fuel pressure, Fuel pump, Engine.
Mileage: No information provided.

Asked on July 24, 2010

1992 GMC Safari Fuel system

Engine Mechanical problem
1992 GMC Safari 6 cyl Two Wheel Drive Automatic 130000 miles

Hi,
Engine sputtered for several minutes like a fuel problem was happening

I replaced the fuel pump, fuel filter and assembly, and sending unit, cleaned the tank, tested the pressure (15 psi)...

what else could it be?
Avatar Asked by moelalon

Answer

Replied on July 24, 2010

Hi moelalon., Welcome to 2carpros and TY for the donation

Is this a 4.3l engine or 4.3l with a turbo? Also is it a TBI or CPI injection system?

TBI pressure should be: 9-13psi

CPI spider assy should be 54-64psi-Please confirm-NOTE: CPI injection its way too low-could be the pressure regulator,fuel pump check valve leaking or a weak pump

Tiny Answered by rasmataz
68 questions asked
Replied on July 28, 2010

fuel pump is new... TBI model 220 4.3 L no turbo... fp comes on for 2 seconds when cranked but won't start... no fuel to TBI... gets fuel to new fuel filter... relays have power to them and pump comes on okay... no damage to lines... new clean fuel in tank...

what could it be?

started and ran good for 2 months... idle was fast though

Tiny Response from moelalon
2 questions asked
Replied on July 28, 2010

Check the fuel pressure with a gauge to rule out a defective new fuel pump if okay -also check if the injectors are pulsing

Tiny Answered by rasmataz
68 questions asked

Replied on July 30, 2010

Already checked the pressure on pump 15psi... and the injectors are pulsing...

what else?

Tiny Response from moelalon
2 questions asked
Replied on July 30, 2010

If the injectors are pulsing it should be getting fuel to the cylinders-you can see this while cranking it over if so-Check if you are getting spark

Tiny Answered by rasmataz
68 questions asked
Replied on July 30, 2010

I am getting spark.... fuel is not flowing to TBI... no fuel is coming through fuel line at TBI carburator...

Tiny Response from moelalon
2 questions asked

Replied on July 31, 2010

Already checked the pressure on pump 15psi... and the injectors are pulsing...

How did you get the fuel pressure and how did you do it.

You got fuel pressure that's over 2psi, injectors are opening and closing meaning its pulsing *****( fuel is not flowing to TBI )***** I don't understand this part

Tiny Answered by rasmataz
68 questions asked
Replied on July 31, 2010

Hi,

I tested the fuel pressure at the fuel filter...

I disconnected the fuel line at the carb... or TBI as it is called on this model... there is no gas flow to the throttle body injector...

Tiny Response from moelalon
2 questions asked
Replied on July 31, 2010

If you are gettig fuel pressure up to the TB and injectors are pulsing and not going thru replace the fuel pressure regulator to do this you have to replace the fuel metering body

Tiny Answered by rasmataz
68 questions asked
Replied on July 31, 2010

I just said that I WAS NOT getting fuel pressure to the TB

read the thread again... you don't seem to understand

Tiny Response from moelalon
2 questions asked