Bad fuel pump?
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Joined: Feb 2015
Posts: 265
Likes: 12
From: Cambridge City, IN
Car: 1991 RS
Engine: 355
Transmission: TH350
Axle/Gears: 4.11
Bad fuel pump?
my car sometimes stalls out at a stop sign. I got a code 54, which is a fuel pump circuit. I then got a fuel pressure tester, and capped of the vacuum line and the FPR line, and my reading was 45 psi at idle. I turned the car off and let it set for 10 minutes and the pressure dropped down to 30 psi. I put everything back and went for a drive. I got back from the drive and put it into park and it bogged down. I then capped off the vacuum and FPR line and let it idle. It idle, but blew out a bunch of black smoke. Thanks
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Joined: May 2015
Posts: 1,154
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From: Temecula, CA
Car: 1989 Pontiac Formula 350
Engine: L98
Transmission: 700R4
Axle/Gears: BorgWarner 3.27 Posi
Re: Bad fuel pump?
The fuel pressure you read seems fine.
Did you check the voltage at the pump?
Note:
CODE 54
Trouble Code 54 indicates a low voltage at the fuel pump. If the voltage at terminal "A20" is less than 4 volts for .4 seconds since the last reference pulse was received, the code will be set.
Possible causes include:
1. Faulty fuel pump relay.
2. Faulty connection at ECM.
3. Faulty oil pressure switch.
4. Faulty ECM.
Did you check the voltage at the pump?
Note:
CODE 54
Trouble Code 54 indicates a low voltage at the fuel pump. If the voltage at terminal "A20" is less than 4 volts for .4 seconds since the last reference pulse was received, the code will be set.
Possible causes include:
1. Faulty fuel pump relay.
2. Faulty connection at ECM.
3. Faulty oil pressure switch.
4. Faulty ECM.
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