Concequences of stuck open injector '96 LT1?
06-02-2013, 07:01 PM
#1
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UPDATE; Concequences of stuck open injector '96 LT1?
UPDATE IN NEW POST.
In the course of installing a REMANUFACTURED Long Block, in one of my 1996 Impala SS's, I installed a set of "Cleaned, Flow Tested Fuel injectors", purchased from a repuable vendor). The engine started OK, but sounded like it had a weak or inop cylinder.
In a minute or two, it started missfireing badly and shut down. On the second and third try, while I read "DataStream" on my OBD II scanner, it missfired for about a minute or two and died.
With the engine off, I connected a Fuel Pressure Gauge, to the schreader valve, on the fuel rail. The gauge read 40 PSI when the Fuel pump ran, but immediatly dropped to 0, when the pump turned off.
I raised the fuel rail up, exposing the Fuel Injector tips, and saw #8 injector was spraying out a continues mist/spray of fuel, until the pressure went to 0.
I replaced the #8 injector and it ran better, but still missfired. I redid the Fuel PSI test and the fuel pressure now drops from 40 PSI to approx. 20 PSI, in about 10-15 minutes. I know other injectors must be leaking.
MY QUESTION, what impac might these leaking injectors have had, on my cylinder walls/rings, while I ran it, on initial break in?
I will be ordering NEW "Delphi" Fuel Injectors and performing a compression test.
In the course of installing a REMANUFACTURED Long Block, in one of my 1996 Impala SS's, I installed a set of "Cleaned, Flow Tested Fuel injectors", purchased from a repuable vendor). The engine started OK, but sounded like it had a weak or inop cylinder.
In a minute or two, it started missfireing badly and shut down. On the second and third try, while I read "DataStream" on my OBD II scanner, it missfired for about a minute or two and died.
With the engine off, I connected a Fuel Pressure Gauge, to the schreader valve, on the fuel rail. The gauge read 40 PSI when the Fuel pump ran, but immediatly dropped to 0, when the pump turned off.
I raised the fuel rail up, exposing the Fuel Injector tips, and saw #8 injector was spraying out a continues mist/spray of fuel, until the pressure went to 0.
I replaced the #8 injector and it ran better, but still missfired. I redid the Fuel PSI test and the fuel pressure now drops from 40 PSI to approx. 20 PSI, in about 10-15 minutes. I know other injectors must be leaking.
MY QUESTION, what impac might these leaking injectors have had, on my cylinder walls/rings, while I ran it, on initial break in?
I will be ordering NEW "Delphi" Fuel Injectors and performing a compression test.
Last edited by Mikeceli; 06-07-2013 at 11:48 AM.
06-07-2013, 11:47 AM
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I installed the 8 NEW "Delphi" fuel injectors.
I drained the oil, saving a sample and checked it for metallic contamination. It was clear. I also tested the oil for excessive Gasoline contamination by attempting to "Light" a half teaspoon sample, with a match. It did not light.
A compression test of the cylinder with the gushing fuel injector and a different cylinder, were both 180 PSI.
I cleaned the spark plugs and installed them.
It started and ran as it should. Took longer to go int "Closed Loop", possibly due to carbon on the 4 New Delphi O2 sensors, I had installed w/ the engine.
Time will tell when I drive and put MILES ON IT! THANKS.
Lesson Learned : NO MORE "Cleaned And Flow Tested" Fuel Injectors, for me!
I drained the oil, saving a sample and checked it for metallic contamination. It was clear. I also tested the oil for excessive Gasoline contamination by attempting to "Light" a half teaspoon sample, with a match. It did not light.
A compression test of the cylinder with the gushing fuel injector and a different cylinder, were both 180 PSI.
I cleaned the spark plugs and installed them.
It started and ran as it should. Took longer to go int "Closed Loop", possibly due to carbon on the 4 New Delphi O2 sensors, I had installed w/ the engine.
Time will tell when I drive and put MILES ON IT! THANKS.
Lesson Learned : NO MORE "Cleaned And Flow Tested" Fuel Injectors, for me!
06-07-2013, 11:53 AM
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It will take longer for the new motor to go into closed loop as the computer can take up to 60 miles to "re-learn" it's programming with the new feedback from the fresh motor. Sounds like you dodged a bullet.
06-08-2013, 12:43 AM
#5
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The main thing that keeps the computer from going closed loop are the O2 sensors. It sounds like yours were carbon fouled. They should be OK as the junk burns off and they get back to performing normally.