84 = hard start
Thread Starter
Cruising
Joined: Jul 2011
Posts: 14
Likes: 0
From: dirty ohio
84 = hard start
For some reason my 84 Corvette is starting hard. It takes like 5 seconds of cranking for the car to start. I guess its starting from the oil pressure switch.
It seems that my 84 corvette fuel pump isn't turning on with the key. Today I went out and got a new f/p relay and the fuel pump still does not turn on when you turn the key forward.
If i put power to one of the red wires on the f/p relay, the pump turns on and will run.
The fuel pump is 7 months old and my relay just came from the store. The fuel pump fuse is good.
How does the 84 fuel pump work? (can someone explain?
Does it come on for 3 sec and then go off until started?
Does the pump run full time when the key is forward?
Why does the fuel pump come on when I put power on one of the red wires on the (A) TERMINAL of the f/p relay?
thanks RWM
It seems that my 84 corvette fuel pump isn't turning on with the key. Today I went out and got a new f/p relay and the fuel pump still does not turn on when you turn the key forward.
If i put power to one of the red wires on the f/p relay, the pump turns on and will run.
The fuel pump is 7 months old and my relay just came from the store. The fuel pump fuse is good.
How does the 84 fuel pump work? (can someone explain?
Does it come on for 3 sec and then go off until started?
Does the pump run full time when the key is forward?
Why does the fuel pump come on when I put power on one of the red wires on the (A) TERMINAL of the f/p relay?
thanks RWM
Le Mans Master
Joined: Feb 2005
Posts: 6,494
Likes: 566
From: Clearwater Florida
..... Take a close look at the plastic harness connector that plugs into the fuel pump relay ... if it has any corrosion or shows any sign of melting , replace it .....
..... I can't speak with authority about your '84 but typical EFI systems have the fuel pump commanded by the ECM to run for 2-3 seconds when the key is turned on to prime the system with fuel ... the pump will not continue to run unless the engine starts ... if you jumper the terminals and get the pump to run you are merely bypassing the relay ... hot wiring it ... you can check the relay by touching it or by listening through a stethoscope while an assistant operates the key switch ... you want to feel or hear it click when turned on and click off shortly thereafter ... make sure you're dealing with the fuel pump relay on the firewall ('87 ) not the engine cooling fan relay (identical ) near the brake master cyl .........
..... There is a terminal on the ALDL connector for hot wiring the fuel pump ... check your Factory Service Manual for the correct pin location .....
..... I can't speak with authority about your '84 but typical EFI systems have the fuel pump commanded by the ECM to run for 2-3 seconds when the key is turned on to prime the system with fuel ... the pump will not continue to run unless the engine starts ... if you jumper the terminals and get the pump to run you are merely bypassing the relay ... hot wiring it ... you can check the relay by touching it or by listening through a stethoscope while an assistant operates the key switch ... you want to feel or hear it click when turned on and click off shortly thereafter ... make sure you're dealing with the fuel pump relay on the firewall ('87 ) not the engine cooling fan relay (identical ) near the brake master cyl .........
..... There is a terminal on the ALDL connector for hot wiring the fuel pump ... check your Factory Service Manual for the correct pin location .....
Last edited by C409; Jul 23, 2011 at 08:30 PM.
Thread Starter
Cruising
Joined: Jul 2011
Posts: 14
Likes: 0
From: dirty ohio
thanks C409,
If i jump the aldl connector for the fuel pump, it will run. Without jumping the aldl the pump will not turn on when I turn the key forward. I will check and see if the relay connectors have any corriosion
Is the green and white wire on the relay, a postive or ground
If i jump the aldl connector for the fuel pump, it will run. Without jumping the aldl the pump will not turn on when I turn the key forward. I will check and see if the relay connectors have any corriosion
Is the green and white wire on the relay, a postive or ground
Burning Brakes
Joined: May 2011
Posts: 838
Likes: 2
From: Louisville Ky
thanks C409,
If i jump the aldl connector for the fuel pump, it will run. Without jumping the aldl the pump will not turn on when I turn the key forward. I will check and see if the relay connectors have any corriosion
Is the green and white wire on the relay, a postive or ground
If i jump the aldl connector for the fuel pump, it will run. Without jumping the aldl the pump will not turn on when I turn the key forward. I will check and see if the relay connectors have any corriosion
Is the green and white wire on the relay, a postive or ground
