Code 42 and 54.
09-28-2013, 09:54 PM
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Car: 92 Quasar blue TA
Engine: L98
Transmission: T5
Axle/Gears: 3.42
Code 42 and 54.
So I bought this 1992 TA 5.7 has a slight miss, so I checked timing and vacuum for leaks. All good... Did find an oil leak on rear of intake. So I took the intake off and installed new gaskets. Now getting a code 42 and 54. Checked timing and vacuum 3 more times was good. Checked all connections and all were in place. Can't figure this out. Any thoughts?? Thanks....
09-28-2013, 11:24 PM
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Car: 1989 SS
Engine: LT1+1500$ hooker exhaust
Transmission: T56
Axle/Gears: 3.42 bogger
Re: Code 42 and 54.
So I bought this 1992 TA 5.7 has a slight miss, so I checked timing and vacuum for leaks. All good... Did find an oil leak on rear of intake. So I took the intake off and installed new gaskets. Now getting a code 42 and 54. Checked timing and vacuum 3 more times was good. Checked all connections and all were in place. Can't figure this out. Any thoughts?? Thanks....
Take the coil off and test it with a multimeter.
code 54 Generally it indicates there was a loss of fuel pump voltage while the engine was running.
If the fuel pump voltage is below 2 volts for over 1.5 seconds while the ecm is recieving ignition module pulses. It sets the code.
If the fuel pump relay goes bad, you will have extended engine cranking until the engine oil pressure is high enough to close the oil pressure switch that sends voltage to the fuel pump.
The relay is mainly there to supply voltage to the fuel pump until the engine starts.
09-29-2013, 12:24 AM
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Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: Code 42 and 54.
That is why there are diagnostic charts in service manuals to follow through in order to identify where the problem lies.
http://www.chevythunder.com/est_code_42.htm
http://www.chevythunder.com/fuel_pump_code_54.htm
http://www.chevythunder.com/est_code_42.htm
http://www.chevythunder.com/fuel_pump_code_54.htm
09-29-2013, 12:32 AM
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Car: 92 Quasar blue TA
Engine: L98
Transmission: T5
Axle/Gears: 3.42
Re: Code 42 and 54.
Hey 89 thanks for the help!! Found bad ground wire behind dist. That was broke. Redid wire ran it for about 20 miles no codes!! Still has a slight miss but I think tuneup will solve that. Was an LB9 car with L89 swap. Doesn't seem as quick as my 92 Formula L98. Vortec coming this winter.
Vetteoz I knew what codes were just didn't know how to go about solving..
Vetteoz I knew what codes were just didn't know how to go about solving..
12-07-2014, 09:59 PM
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Car: 87 GTA Trans Am
Engine: 5.7 350 TPI
Transmission: TCI transmission
Axle/Gears: 4th gen rear end. With 3.83
Re: Code 42 and 54.
Hey 89 thanks for the help!! Found bad ground wire behind dist. That was broke. Redid wire ran it for about 20 miles no codes!! Still has a slight miss but I think tuneup will solve that. Was an LB9 car with L89 swap. Doesn't seem as quick as my 92 Formula L98. Vortec coming this winter.
Vetteoz I knew what codes were just didn't know how to go about solving..
Vetteoz I knew what codes were just didn't know how to go about solving..
Where was this ground wire? Any pics on it?
12-07-2014, 10:01 PM
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Car: 87 GTA Trans Am
Engine: 5.7 350 TPI
Transmission: TCI transmission
Axle/Gears: 4th gen rear end. With 3.83
Re: Code 42 and 54.
Check all you grounds and make damn sure there right. 42 The EST circuit voltage was below 0.5 volts when engine speed was below 3000 RPM.
Take the coil off and test it with a multimeter.
code 54 Generally it indicates there was a loss of fuel pump voltage while the engine was running.
If the fuel pump voltage is below 2 volts for over 1.5 seconds while the ecm is recieving ignition module pulses. It sets the code.
If the fuel pump relay goes bad, you will have extended engine cranking until the engine oil pressure is high enough to close the oil pressure switch that sends voltage to the fuel pump.
The relay is mainly there to supply voltage to the fuel pump until the engine starts.
Take the coil off and test it with a multimeter.
code 54 Generally it indicates there was a loss of fuel pump voltage while the engine was running.
If the fuel pump voltage is below 2 volts for over 1.5 seconds while the ecm is recieving ignition module pulses. It sets the code.
If the fuel pump relay goes bad, you will have extended engine cranking until the engine oil pressure is high enough to close the oil pressure switch that sends voltage to the fuel pump.
The relay is mainly there to supply voltage to the fuel pump until the engine starts.
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