Corvette fuel problem
Thread Starter
Cruising
Joined: Jun 2012
Posts: 12
Likes: 0
Corvette fuel problem
Hi Guys and gals.
Bit cold over the pond here so will keep it short and sweet.
Ive just installed a nearly new tested fuel pump/sender unit after my last sender unit rotted out. Before i removed the old one, when you turned the ignition on you could hear the pump prime for the two seconds. Now ive installed the replacement, nothing, tried the old unit, nothing, only getting approx 2 volts to the fuse when i turn the ignition on. The car did sit around for approx 5 months before i bought a replacement part.
I have been under the hood, the relay is no where near the brake booster/windscreen wiper motor. nor is it under the passenger side of the dash which i have stripped apart.
I need to find this relay as it sounds like its stuck doesnt it?
My corvette is an 1990, 5.7 L98 engined coupe.
PLEASE HELP, Its driving me nuts!
Bit cold over the pond here so will keep it short and sweet.
Ive just installed a nearly new tested fuel pump/sender unit after my last sender unit rotted out. Before i removed the old one, when you turned the ignition on you could hear the pump prime for the two seconds. Now ive installed the replacement, nothing, tried the old unit, nothing, only getting approx 2 volts to the fuse when i turn the ignition on. The car did sit around for approx 5 months before i bought a replacement part.
I have been under the hood, the relay is no where near the brake booster/windscreen wiper motor. nor is it under the passenger side of the dash which i have stripped apart.
I need to find this relay as it sounds like its stuck doesnt it?
My corvette is an 1990, 5.7 L98 engined coupe.
PLEASE HELP, Its driving me nuts!
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
If so you may be on your own as to where the relay is now
and on a '90 it is under the dash ( somewhere? )
'89 and earlier it was in the engine bay
Where it is supposed to be .Fig 23
Last edited by vetteoz; Jan 19, 2013 at 07:35 AM.
Le Mans Master
Joined: Feb 2005
Posts: 6,475
Likes: 565
From: Clearwater Florida
............ Your issue could be VATS related ... try another ignition key if you have one and make sure the metal contacts on the "pill" are clean ... check your factory service manual for diagnostics ... you can power up the fuel pump from the ALDL connector ... provide 12v to the G terminal and check operation ... this bypasses the relay and the oil switch ........
Thread Starter
Cruising
Joined: Jun 2012
Posts: 12
Likes: 0
[QUOTE=vetteoz;1582881710]Has the car been converted to RHD ?
If so you may be on your own as to where the relay is now
and on a '90 it is under the dash ( somewhere? )
'89 and earlier it was in the engine bay
QUOTE]
Well being an import and knowing how wonderful our agencys are here, it could be an 89 or 90! i have a 1998 car which was pictured at a motor show which somehow they registered as a 1999!
As for the pump, with a little more playing it appears the used pump is duff i was sent. Do they stick when stood for a while? If i tap the pump will it 'loosen' it up at all?
The oil pressure switch, is it the one at the back of the head by the distributor? Mine only has 1 wire? Not sure how its supposed to supply current to the pump with only 1! is there another one i should be aware of?
Thanks for your help so far guys, still going to hunt the relay down.
If so you may be on your own as to where the relay is now
and on a '90 it is under the dash ( somewhere? )
'89 and earlier it was in the engine bay
QUOTE]
Well being an import and knowing how wonderful our agencys are here, it could be an 89 or 90! i have a 1998 car which was pictured at a motor show which somehow they registered as a 1999!
As for the pump, with a little more playing it appears the used pump is duff i was sent. Do they stick when stood for a while? If i tap the pump will it 'loosen' it up at all?
The oil pressure switch, is it the one at the back of the head by the distributor? Mine only has 1 wire? Not sure how its supposed to supply current to the pump with only 1! is there another one i should be aware of?
Thanks for your help so far guys, still going to hunt the relay down.
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
fuse?
Hi James Holland,
If you did not disconnect the battery while you were replacing the pump, might it be the fuse?
Believe there is possibly 2 fuses for the fuel pump on the passenger side fuse panel, accessible with the door open.
If you did not disconnect the battery while you were replacing the pump, might it be the fuse?
Believe there is possibly 2 fuses for the fuel pump on the passenger side fuse panel, accessible with the door open.
Thread Starter
Cruising
Joined: Jun 2012
Posts: 12
Likes: 0
Right. just to add to confussion, i cannot hear the pump at all. Even with me with my ear next to the filler!
BUT
I went to remove the tank unit to inspect the pump etc, and i have decent fuel pressure coming from the pipe which i presume is the tank return, i have no pressure from the pump side of the sender unit.
Any idea? I dont see why i have pressure coming from the return out of the tank?
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
I did,
Right. just to add to confussion, i cannot hear the pump at all. Even with me with my ear next to the filler!
BUT
I went to remove the tank unit to inspect the pump etc, and i have decent fuel pressure coming from the pipe which i presume is the tank return, i have no pressure from the pump side of the sender unit.
Any idea? I dont see why i have pressure coming from the return out of the tank?
Right. just to add to confussion, i cannot hear the pump at all. Even with me with my ear next to the filler!
BUT
I went to remove the tank unit to inspect the pump etc, and i have decent fuel pressure coming from the pipe which i presume is the tank return, i have no pressure from the pump side of the sender unit.
Any idea? I dont see why i have pressure coming from the return out of the tank?
Any chance the inlet/outlet are switched?
Perhaps since it is a used one, it is from a different year/model and the inlet/outlet are on different sides that year versus yours?
suggest comparing to original to be sure.
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