fuel pump code?
Thread Starter
Instructor
Joined: Jun 2003
Posts: 200
Likes: 0
From: Tempe AZ
fuel pump code?
On my 85, it throws a code (I forgot which) but it translates into low voltage to fuel pump. The fuel pump is relatively new, is it dying? Maybe a bad wire going to fuel pump? Where should I start with this?
Maybe its not even the fuel pump, cause I know I need 8 new fuel injectors. Thats what a trusted mechanic told me anyhow, so I'm looking at those 24# Ford SVO's...
Maybe its not even the fuel pump, cause I know I need 8 new fuel injectors. Thats what a trusted mechanic told me anyhow, so I'm looking at those 24# Ford SVO's...
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: fuel pump code? (Corvettaholic)
My recommendation: Don't start of by going to the opposite end of the spectrum - the injectors. The cost and work involved isn't justificable unless the other, more common, possible causes are checked first.
The Shop Manual for the 86 (now your 85) shows several tests that should be run to isolate the cause.
Could be a faulty fuel pump relay, oil pressure switch, short or open ground or even ECM.
Don't become a parts changer. There lots of Forum members who insist on throwing parts at a problem, hoping that one of them will solve their problem. "Ain't" the way to go about it.
Jake
The Shop Manual for the 86 (now your 85) shows several tests that should be run to isolate the cause.
Could be a faulty fuel pump relay, oil pressure switch, short or open ground or even ECM.
Don't become a parts changer. There lots of Forum members who insist on throwing parts at a problem, hoping that one of them will solve their problem. "Ain't" the way to go about it.
Jake
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: fuel pump code? (JAKE)
:iagree:
If the code pops up on startup the problem could be the fuel pump relay.
If it comes after startup it's likely the oil pressure switch (with the Orn & Red wires) as the relay is only used to prime the fuel rail at startup.
The ECM measures voltage available at the pump and that voltage can come from only one of the two above sources.
Also, you can monitor fuel pump voltage at ALDL pin "G", lower left.
If the code pops up on startup the problem could be the fuel pump relay.
If it comes after startup it's likely the oil pressure switch (with the Orn & Red wires) as the relay is only used to prime the fuel rail at startup.
The ECM measures voltage available at the pump and that voltage can come from only one of the two above sources.
Also, you can monitor fuel pump voltage at ALDL pin "G", lower left.
Thread Starter
Instructor
Joined: Jun 2003
Posts: 200
Likes: 0
From: Tempe AZ
Re: fuel pump code? (65Z01)
I've heard the word fuel pump relay quite a bit, where is it at anyway? Is there a way to check it, and is it cheap to replace? I don't want to touch the fuel pump if I don't have to, and besides... it shouldn't go bad already cause it sounds and works fine. What exactly does the oil pressure switch do and where is it?
