I hot wired a relay in the trunk and I was wondering how long it will take for the pump to stop priming. The factory relay clicks after about 8-10 seconds. The aftermarket relay does not, the pump continues to prime until you start the car. My concern is that there will be too much fuel in the rails if I leave the key turned on and could cause some harm. Also, I am having a problem with the fuel guage, it is not giving an accurate reading. Is there a way to reset it. When the tank is full it reads past full. Thanks guys.
Hot wired relay questions
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jhanson1750
just a 10th quicker
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Sounds like you may have used the incorrect "trigger" for your relay. I built my own hotwire kit but they are all basically the same you should have used the wire that used to power your pump to fire the new relay. That should make the pump time out just as it used to. If you wired it correctly you might want to recheck all your terminations to verify they are all correct. IF nojoy at that point post up how you wired the relay and maybe we can shed some light on the problem. 
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I agree with jhanson1750, you must have the incorrect fuel pump hot wire relay SIGNAL wire leading to the relay to close the relay.
If its a 86-87, use the black connector with grey wire behind the alternator as the signal wire, not the primary voltage wire.
As for the hanger not reading correctly causing the gauge to read high, this will also cause the car to run out of fuel at 1/4 tank.
What year is it?
Very common to have a bent arm, or the sender is tarnished so its not reading right.
post back
BW
If its a 86-87, use the black connector with grey wire behind the alternator as the signal wire, not the primary voltage wire.
As for the hanger not reading correctly causing the gauge to read high, this will also cause the car to run out of fuel at 1/4 tank.
What year is it?
Very common to have a bent arm, or the sender is tarnished so its not reading right.
post back
BW
Its a 1984 Monte Carlo SS with a 87 GN drivetrain,. I used the ignition from the fuse box as the trigger, none of the wires leading to the trunk are getting any power so I just ran it direct. The other wires I ran are the Main wire from the alternator post, the ground, and of course the wire to the pump.
I doubt that the float is bent in anyway as I inspected it when I replaced the pump. Will it reset itself after it goes below the previous level? The guage was reading correctly when I checked for leaks when the tank was down. When I put the tank up it read about a half a tank when there was in fact about a quarter tank. Now when I filled it up it reads above full.
I doubt that the float is bent in anyway as I inspected it when I replaced the pump. Will it reset itself after it goes below the previous level? The guage was reading correctly when I checked for leaks when the tank was down. When I put the tank up it read about a half a tank when there was in fact about a quarter tank. Now when I filled it up it reads above full.
machinegun
Active Member
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the system is a return system excess pressure and flow are redirected back to the tank. there is no need to worry. Make sure you are getting good amperage and voltage to the pump so it can keep up with the demands that the engine puts on the fuel system. You are worying over nothing.
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The reason why the fuel pump stays on the entire time with the key on, is because you are using the acc signal from the fuse panel. That is why the fuel pump stays on, key on power all the time.
I would be worried if the car was in a wreck, then the fuel pump would stay on and catch the car on fire because your not using the correct signal wire.
In my previous post on this thread, i said for you to look behind the alternator, that grey wire with the black connector should be your signal wire for the fuel pump. IT will allow the pump to prime, then shut off, IF your stock relay on the pass side is working. The wire should be very short and will be sticking out of the drivers side valve cover wiring harness, the other short wire is the green connector wire, it is for the TACH signal wire.
Now, i assume that the gauge is still "working" goes up and down with more and less fuel correct? Even thou its pegged past full, will the fuel level come down after you have put 100 miles on it?
I think if the signal wire from the sender is pinched, the gauge will go to empty, if its unhooked, hmmm i forget.
Lets start there.
BW
I would be worried if the car was in a wreck, then the fuel pump would stay on and catch the car on fire because your not using the correct signal wire.
In my previous post on this thread, i said for you to look behind the alternator, that grey wire with the black connector should be your signal wire for the fuel pump. IT will allow the pump to prime, then shut off, IF your stock relay on the pass side is working. The wire should be very short and will be sticking out of the drivers side valve cover wiring harness, the other short wire is the green connector wire, it is for the TACH signal wire.
Now, i assume that the gauge is still "working" goes up and down with more and less fuel correct? Even thou its pegged past full, will the fuel level come down after you have put 100 miles on it?
I think if the signal wire from the sender is pinched, the gauge will go to empty, if its unhooked, hmmm i forget.
Lets start there.
BW
I'll run the trigger from the alternator post, no problem. It is a stock 87 GN set-up as far as the fuel lines and return lines go. I'm not worried as the car runs fine, but I was worried about safety concerns as the ignition would not turn the pump off in case of an accident.
The fuel gauge goes down as it should but it way too high, when full its past the F. I have yet to run it down below 1/2 a tank since I changed the fuel pump.
Also, what could happen if the sock falls off on the pump, it was just barely on there, but the other one I took offr came off really easy too so I assume that this is the way it is supposed to be.
The fuel gauge goes down as it should but it way too high, when full its past the F. I have yet to run it down below 1/2 a tank since I changed the fuel pump.
Also, what could happen if the sock falls off on the pump, it was just barely on there, but the other one I took offr came off really easy too so I assume that this is the way it is supposed to be.
For the hotwire trigger you should use either of the following
1 the trigger wire for the stock relay if you are not using the stock relay. you can either connect to this wire at the stock relay location or where it comes out of the ECM. I don't know the location of the trigger wire on the ECM but you should be able to find it by searching here or on the GNttype.org site.
2 the power out on the stock relay if you are using the stock relay.
The grey wire behind the alternator is used for testing the fuel pump. I will not work as a trigger wire.
David
87GN
1 the trigger wire for the stock relay if you are not using the stock relay. you can either connect to this wire at the stock relay location or where it comes out of the ECM. I don't know the location of the trigger wire on the ECM but you should be able to find it by searching here or on the GNttype.org site.
2 the power out on the stock relay if you are using the stock relay.
The grey wire behind the alternator is used for testing the fuel pump. I will not work as a trigger wire.
David
87GN
