1992 Chevrolet Corvette no power to fuel pump

DSVETT

MEMBER
1992 CHEVROLET CORVETTE
5.4L
V8
2WD
AUTOMATIC
125,000 MILES

Here is what it is not:

Fuel Pump this items tested out good
in line fuel filter this item tested out good
fuse panel and fp1 15 amp fuse is ok
relay for fp1 has been tested out good
ECM has tested out good.
Car will start and run fine when power applied directly to the fuel pump giving the fuel rail pressure.
when key is turned to the on position the 15 amp fuse engages for approximately 2 seconds which is what it is designed to do.
alarm has tested out good and functioning as designed
key is obviously ok since it provides 2 seconds to fuse when turned on.
re-setting the ECM did not produce any power to pump

the issue is that no power gets through the harness to the fuel pump in the tank.
the grey wire does not register any power when key is engaged.
also
in reading about the alarm/security system it says to check out the security system you put the key in and turn in on without trying to start and see if the security light comes on. Well mine does not come on. Is this a key/cylinder issue do ya think?

5 Replies

HMAC300

MECHANIC
48,601 POSTS

Fuel pump will only pump for 2 seconds when key is turned on after car starts oil pressure switch takes over. See if it is working. Try resetting security system as well.

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Monday, July 6th, 2015 AT 12:06 PM

DSVETT

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4 POSTS

Thanks I already knew the 2 second point.
Here is how I tried to reset:
1. Removed battery cable for 5 minutes and it did not reset
2. Locked the car and closed doors and security light came on and flashed as it is designed then turned off I waiting a few seconds then open the door with the door key and it turned off that part of the system however no help on the key issue.
3. I also let the engine turn over until I had oil pressure and it still did not allow the fuel pump to come on

any other ideas
do you think it is with the tumbler in the ignition key port

thanks

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Monday, July 6th, 2015 AT 1:36 PM

HMAC300

MECHANIC
48,601 POSTS

I ind of doubt it's the ignition switch. If you have a different key try that as it's diode in key that tells it to turn on or off. It will disable fuel an dspark so I think that is the problem. Check the starter enable relay see pics that may also be the problem. Otherwise you'll need a tech 1 to see if it's the alarm system or not. I kind of think it is.

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Monday, July 6th, 2015 AT 3:41 PM

DSVETT

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4 POSTS

I thought I would put my original note back to you it may have not been where you could see what has been verified.

?Fuel Pump this items tested out good
in line fuel filter this item tested out good
fuse panel and fp1 15 amp fuse is ok
relay for fp1 has been tested out good
ECM has tested out good.
Car will start and run fine when power applied directly to the fuel pump giving the fuel rail pressure.
When key is turned to the on position the 15 amp fuse engages for approximately 2 seconds which is what it is designed to do.
Alarm has tested out good and functioning as designed
key is obviously ok since it provides 2 seconds to fuse when turned on.
Re-setting the ECM did not produce any power to pump
i tried the other key and no change in the symtom.
I would gladly contribute to you for information if I could get something more concrete that I haven't already done.
Thank you
is there another way to reset the system then what I have already tried?

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Monday, July 6th, 2015 AT 4:19 PM

HMAC300

MECHANIC
48,601 POSTS

I did read what you said the first time but if the security system is engaged it shuts the fuel off so when you jump it you are by passing the security system to make it run. I'm not that sharp on corvettes but I'm sure its' a security problem an dyou need a tech 1 or similar scanner to check that out. I went to our manual and saw no way to reset it other than trying a different key. I have no other suggestions.