Any wiring experts on...fuel pump relay
28-01-2009, 09:57 PM
#1
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Any wiring experts on...fuel pump relay
Im having trouble with the fuel pump on the RS1600i.
Ive done some testing with multimeter on the fuel pump wiring and the relay! All the wiring is fine. Getting 12.40 volts at the switched red wires at the relay, But getting no reading at the red/black wire that feeds the pump when cranking. I have 4 relays, so i would have thought that its unlikely all are buggered? Anyways, i opened one up and plugged it in, open. The contacts on that (excuse my lack of technical jargon) coily thing dont move and dont make contact. If i bridge those contacts with an insulated screwdriver the bump buzzes! So theres no wiring fault to the relay or to the pump
So, what makes the contacts close. When you turn ignition on the pump primes so they must close then open up after a second or so( or should i say should prime, but it is NOT doing so at the moment). So, when cranking, what makes them close? Perhaps this is where my fault lies? But i have no idea what im looking for?
If anyone can help, id be very greatful!
Ive done some testing with multimeter on the fuel pump wiring and the relay! All the wiring is fine. Getting 12.40 volts at the switched red wires at the relay, But getting no reading at the red/black wire that feeds the pump when cranking. I have 4 relays, so i would have thought that its unlikely all are buggered? Anyways, i opened one up and plugged it in, open. The contacts on that (excuse my lack of technical jargon) coily thing dont move and dont make contact. If i bridge those contacts with an insulated screwdriver the bump buzzes! So theres no wiring fault to the relay or to the pump
So, what makes the contacts close. When you turn ignition on the pump primes so they must close then open up after a second or so( or should i say should prime, but it is NOT doing so at the moment). So, when cranking, what makes them close? Perhaps this is where my fault lies? But i have no idea what im looking for?
If anyone can help, id be very greatful!
28-01-2009, 10:32 PM
#2
the relay will be activated by the ecu whe it recieves a crank signal, a quick test for you, when you crank the engine does the revs counter show the cranking speeds (approx 200rpm ish) if o the ecu is recieveing the signal from the sensor, that being as long as the ecu has the correct +ve's and -ve's.
the relay will have a built in timer for prime on ignition on.
the relay will have a built in timer for prime on ignition on.
28-01-2009, 10:41 PM
#3
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As mark says above.
The fuel pump relay isnt a normal relay.
It has a small electronic timer and pulse capture circuit to turn the relay on and off.
No ignition pulse/spark...no fuel pump running... Its a safety feature.
Check for a spark first..
The fuel pump relay isnt a normal relay.
It has a small electronic timer and pulse capture circuit to turn the relay on and off.
No ignition pulse/spark...no fuel pump running... Its a safety feature.
Check for a spark first..
Last edited by ECU Monitor Enthusiast; 28-01-2009 at 10:42 PM.
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