Replacing Fuel Pump
Melting Slicks
Joined: Feb 2005
Posts: 2,057
Likes: 5
From: Bay Shore, NY
Team Owner
Joined: Jan 2009
Posts: 73,568
Likes: 33
From: Somewhere in Mo
St. Jude Donor '09-'10, '14
you should be OK for some time. It's not like it's going to fail in the next year. If it does, it's a fluke. but if you ever have a leak down that's the first place I'ld start if your tests determine it's a pump.
Team Owner
Joined: Jan 2009
Posts: 73,568
Likes: 33
From: Somewhere in Mo
St. Jude Donor '09-'10, '14
If you're talking about the FPR. Pull the hose off. The pressure should jump up to well over 40, or at least over your normal reading. If gas starts flowing out of the line your FPR is bad. That happened to me so be ready with a towel to catch any fuel spillage. Actually have the rag wrapped oround the area so noe gets spilled if this happens. If any fuel comes pooring out change the FPR. You can also tape the gauge to your windshield and go for a drive and monitor what the pressure does.
Also before you start take the line off and inspect it to see if there is any fuel present or the smell of fuel.
Also before you start take the line off and inspect it to see if there is any fuel present or the smell of fuel.
Melting Slicks
Joined: Feb 2005
Posts: 2,057
Likes: 5
From: Bay Shore, NY
Lesson learned on this one. If the problem comes up again, I will replace the pulsator with a piece of hose.
Melting Slicks
Joined: Feb 2005
Posts: 2,057
Likes: 5
From: Bay Shore, NY
If you're talking about the FPR. Pull the hose off. The pressure should jump up to well over 40, or at least over your normal reading. If gas starts flowing out of the line your FPR is bad. That happened to me so be ready with a towel to catch any fuel spillage. Actually have the rag wrapped oround the area so noe gets spilled if this happens. If any fuel comes pooring out change the FPR. You can also tape the gauge to your windshield and go for a drive and monitor what the pressure does.
Also before you start take the line off and inspect it to see if there is any fuel present or the smell of fuel.
Also before you start take the line off and inspect it to see if there is any fuel present or the smell of fuel.
Team Owner
Joined: Jan 2009
Posts: 73,568
Likes: 33
From: Somewhere in Mo
St. Jude Donor '09-'10, '14
When I tested it a few weeks ago, it tested out fine, no fuel in the hose, but I want to definitely see what's going now with a working fuel pump so I will retest. I need to replace the FPR anyway to get the pressure up to 36psi according to Jon at FIC to correctly match the injectors I have.
Melting Slicks
Joined: Feb 2005
Posts: 2,057
Likes: 5
From: Bay Shore, NY
I spoke to Jon at FIC today and he said I can leave it the way it is if its running right or replace the FPR with an adjustable one to boost the pressure. He also suggested removing the vacuum hose to see if the pressure goes up. If it does, then he said I can run without it connected. I'm thinking of installing an AFPR anyway so a call to TPiS is in order.
Team Owner
Joined: Jan 2009
Posts: 73,568
Likes: 33
From: Somewhere in Mo
St. Jude Donor '09-'10, '14
From what I know for the 85, its within spec. The 85 had different injectors from the other years and did not require high fuel pressure. With the Bosch III's that I am currently running, to best atomize the fuel, I need to up the pressure to 36psi, vacuum hose connected, at idle.
I spoke to Jon at FIC today and he said I can leave it the way it is if its running right or replace the FPR with an adjustable one to boost the pressure. He also suggested removing the vacuum hose to see if the pressure goes up. If it does, then he said I can run without it connected. I'm thinking of installing an AFPR anyway so a call to TPiS is in order.
I spoke to Jon at FIC today and he said I can leave it the way it is if its running right or replace the FPR with an adjustable one to boost the pressure. He also suggested removing the vacuum hose to see if the pressure goes up. If it does, then he said I can run without it connected. I'm thinking of installing an AFPR anyway so a call to TPiS is in order.
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Melting Slicks
Joined: Sep 2006
Posts: 3,194
Likes: 27
From: Monroe Twp, NJ
Like this guy wrote with pictures?
http://forums.corvetteforum.com/c4-t...h-article.html
http://forums.corvetteforum.com/c4-t...h-article.html
Melting Slicks
Joined: Feb 2005
Posts: 2,057
Likes: 5
From: Bay Shore, NY
I used those instructions to help me in my little project. I was worried about breaking the tabs off the sending unit, so I acquired a spare. I wound up breaking a tab on the spare, wouldn't you know it. But I put a clamp on it and it holds and doesn't bind the float, it travels freely. Its in my storage cabinet with other C4 parts, just in case. I used my original unit and it cleaned up nice, the gauge works.
I got a chance to check the FPR tonight. Ignition on, pump primed, pressure is 42psi or there abouts and then falls a little. Engine on, with the vacuum hose on, 32psi at idle. With the hose off, 42psi at idle. There was no gas in the line either. I feel better now that I know its working and I don't feel rushed to get me an AFPR.
I got a chance to check the FPR tonight. Ignition on, pump primed, pressure is 42psi or there abouts and then falls a little. Engine on, with the vacuum hose on, 32psi at idle. With the hose off, 42psi at idle. There was no gas in the line either. I feel better now that I know its working and I don't feel rushed to get me an AFPR.
Team Owner
Joined: Jul 2004
Posts: 28,426
Likes: 3,277
From: Hartford WI
I got a chance to check the FPR tonight. Ignition on, pump primed, pressure is 42psi or there abouts and then falls a little. Engine on, with the vacuum hose on, 32psi at idle. With the hose off, 42psi at idle. There was no gas in the line either. I feel better now that I know its working and I don't feel rushed to get me an AFPR.
Melting Slicks
Joined: Feb 2005
Posts: 2,057
Likes: 5
From: Bay Shore, NY
It maintained pressure overnight actually.
Le Mans Master
Joined: Jul 2009
Posts: 6,381
Likes: 66
From: SF bay area C.A.
C4 of the Year Finalist
"I'd have mounted the fuel pump" Thought that was going in a different direction. Dam Friz, you'v got a lot of stars!
Last edited by kimmer; Aug 13, 2010 at 11:59 AM.
