no fuel pressure
Thread Starter
Cruising
Joined: May 2025
Posts: 12
Likes: 1
no fuel pressure
I got a 2001 z06 reading no fuel pressure when cranking. I have a fuel gauge mounted to the end of the fuel rail and noticed when I check on the pressure when sitting over night it sits around 40 and then when I go to crank immediately drops to zero. engine cranks fine, and battery is at 12.6. I pulled the fuel pump relay and fuse and they were good, I tested voltage at the fuse box for the relay and got 12 volts when ignition was on. previous owner had said he recently replaced the fuel pump so I'm stuck as to where to go from here. could the fuel pump have gone bad again?
Thread Starter
Cruising
Joined: May 2025
Posts: 12
Likes: 1
...
yes no pressure with the key turned on. when cranking the tachometer goes to zero as well as all the other gauges on the dash. I checked the relay for connectivity between the two pins will giving power and ground to the other two pins. aswell I tried swapping with a known good relay. I also checked the fuel pump fuse and that was good. I also turned the key to on jumped the switch section of the fuse box for that relay and checked for power and ground between the other two pins and got 12 volts which was normal. I'm fairly certain I don't hear the fuel pump priming when turning the key on.
I'm using a fluke meter
yes no pressure with the key turned on. when cranking the tachometer goes to zero as well as all the other gauges on the dash. I checked the relay for connectivity between the two pins will giving power and ground to the other two pins. aswell I tried swapping with a known good relay. I also checked the fuel pump fuse and that was good. I also turned the key to on jumped the switch section of the fuse box for that relay and checked for power and ground between the other two pins and got 12 volts which was normal. I'm fairly certain I don't hear the fuel pump priming when turning the key on.
I'm using a fluke meter
Last edited by C5 Diag; Aug 24, 2025 at 02:07 PM.
Thread Starter
Cruising
Joined: May 2025
Posts: 12
Likes: 1
...
I had already checked at the fuse box like u said with pins 30 and 87 and the fuel pump did not turn on. I have the cover off the fuel pump and inspected the connection for corrosion just incase and didn't find any. I have to find some longer alligator clips so I can run this voltage drop test but will soon. have you seen resistance coming from these connectors C140 C402? I've recently gone and cleaned and resurfaced all my ground connections so Im inclined to think its not them.
I had already checked at the fuse box like u said with pins 30 and 87 and the fuel pump did not turn on. I have the cover off the fuel pump and inspected the connection for corrosion just incase and didn't find any. I have to find some longer alligator clips so I can run this voltage drop test but will soon. have you seen resistance coming from these connectors C140 C402? I've recently gone and cleaned and resurfaced all my ground connections so Im inclined to think its not them.
Last edited by C5 Diag; Aug 24, 2025 at 01:48 PM.
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Melting Slicks
Joined: Sep 2008
Posts: 3,138
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From: Espanola New Mexico
I am sorry to say that there are many replies here at the corvette forum that sound condensing. We are here to help C5 owners with our combined knowledge and experience to help solve problems.
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
I do not think the replies were condensed at all. Lot's of detail and specifics clearly spelled out.
Melting Slicks
Joined: Sep 2008
Posts: 3,138
Likes: 802
From: Espanola New Mexico
I ment to say condescending, my bad. We might come off this way when we ask people if they have experience and skills needed to solve their cars problems. I do not hesitate to recommend that some forum members take their car to a trusted shop when I realize that they do not have the skills needed to work on their car themselves.
Thread Starter
Cruising
Joined: May 2025
Posts: 12
Likes: 1
[QUOTE=mmartinez;1609049234]I ment to say condescending, my bad. We might come off this way when we ask people if they have experience and skills needed to solve their cars problems. I do not hesitate to recommend that some forum members take their car to a trusted shop when I realize that they do not have the skills needed to work on their car themselves.[/QUOTE
no its just the fact that I had stated multiple times I had tested the components of the circuit and yet his response is a video about testing relays and to go read a book. thought forums would be helpful advice not some old head wanting to lecture
no its just the fact that I had stated multiple times I had tested the components of the circuit and yet his response is a video about testing relays and to go read a book. thought forums would be helpful advice not some old head wanting to lecture
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,595
Likes: 4,055
From: Cape Coral, Florida
[QUOTE=Billymarcin63;1609049316]
OK, Son...getting to what you told us what was done...."I checked the relay for connectivity between the two pins will giving power and ground to the other two pins"...what does this mean ???...connectivity between 2 pins...what two pins and why you checking connectivity ??...by this I can tell you have limited electrical knowledge...that is why I included the video so you UNDERSTAND how a relay functions....there is a control side and a load side....well this "old head" if you are talking about me wishes you luck with your concern....you have a LOT to learn !!!
I ment to say condescending, my bad. We might come off this way when we ask people if they have experience and skills needed to solve their cars problems. I do not hesitate to recommend that some forum members take their car to a trusted shop when I realize that they do not have the skills needed to work on their car themselves.[/QUOTE
no its just the fact that I had stated multiple times I had tested the components of the circuit and yet his response is a video about testing relays and to go read a book. thought forums would be helpful advice not some old head wanting to lecture
no its just the fact that I had stated multiple times I had tested the components of the circuit and yet his response is a video about testing relays and to go read a book. thought forums would be helpful advice not some old head wanting to lecture
OK, Son...getting to what you told us what was done...."I checked the relay for connectivity between the two pins will giving power and ground to the other two pins"...what does this mean ???...connectivity between 2 pins...what two pins and why you checking connectivity ??...by this I can tell you have limited electrical knowledge...that is why I included the video so you UNDERSTAND how a relay functions....there is a control side and a load side....well this "old head" if you are talking about me wishes you luck with your concern....you have a LOT to learn !!!
Last edited by C5 Diag; Aug 24, 2025 at 01:54 PM.
Tech Contributor
Joined: Jan 2007
Posts: 19,454
Likes: 1,162
From: Dyer, IN
[QUOTE=Billymarcin63;1609049316]
thanks for explaining who you are 
I ment to say condescending, my bad. We might come off this way when we ask people if they have experience and skills needed to solve their cars problems. I do not hesitate to recommend that some forum members take their car to a trusted shop when I realize that they do not have the skills needed to work on their car themselves.[/QUOTE
no its just the fact that I had stated multiple times I had tested the components of the circuit and yet his response is a video about testing relays and to go read a book. thought forums would be helpful advice not some old head wanting to lecture
no its just the fact that I had stated multiple times I had tested the components of the circuit and yet his response is a video about testing relays and to go read a book. thought forums would be helpful advice not some old head wanting to lecture