Fuel pump runns all time koeo
- Thread starter richardv6
- Start date
fuel pump is powered by 2 circuits.
There is the fuel pump relay on the passenger side fender, it is controlled by the ECM, primes for 2 seconds or so at key on, and activates whenever the ECM sees crank sensor pulses from the ignition module.
There is a secondary control that is part of the oil pressure switch that provides a backup path to run the fuel pump.
So its most likely one of the 3 components, relay, ECM, oil pressure switch/wiring.
Bob
There is the fuel pump relay on the passenger side fender, it is controlled by the ECM, primes for 2 seconds or so at key on, and activates whenever the ECM sees crank sensor pulses from the ignition module.
There is a secondary control that is part of the oil pressure switch that provides a backup path to run the fuel pump.
So its most likely one of the 3 components, relay, ECM, oil pressure switch/wiring.
Bob
- Joined
- Aug 1, 2003
without assuming anything ..
what is your fuel pump setup ,
hotwire adds another culprit to the mix , double pumper more things to check , external another set of rules
your sig suggests the car is far from stock and that opens up other reasons why the pump is running continuos depending on how its wired and what it is
did it just start doing
was it always this way
did you do any recent changes
is it teven the car in your sig
...how bout you give a little more to go on seeing as how you have the car and you didnt give any history leading to your condition
beings you have an xfi the 2 second rule doesnt apply as that prime time is programmable , and if its external it might be wired to be on all the time because the pump doesnt have a check setup so once it stops the fuel pressure drops to zero , so it has to stay on
wouldnt happen to be an external pump would it ?
what is your fuel pump setup ,
hotwire adds another culprit to the mix , double pumper more things to check , external another set of rules
your sig suggests the car is far from stock and that opens up other reasons why the pump is running continuos depending on how its wired and what it is
did it just start doing
was it always this way
did you do any recent changes
is it teven the car in your sig
...how bout you give a little more to go on seeing as how you have the car and you didnt give any history leading to your condition
beings you have an xfi the 2 second rule doesnt apply as that prime time is programmable , and if its external it might be wired to be on all the time because the pump doesnt have a check setup so once it stops the fuel pressure drops to zero , so it has to stay on
wouldnt happen to be an external pump would it ?
richardv6
Active Member
- Joined
- May 11, 2007
all i did was remove factory motor and washed bay then installed new built engine,already had hotwire kit installed for sometime.so i dont think i have issue with that.thought maybe i had some water intrusion in relay or wiring but not totally sure just yet.should i jump the oil pressure switch and see ,if so what 2 wires do i jump.
- Joined
- Aug 1, 2003
so you're saying you had the xfi with the stock motor too, that didnt just go in
so you see there was a lot you left out in your initial post as those guessing or offering advice would have assumed this issue just popped up.
the connector to the sender is rubber , the rubber goes goey over time and falls apart leaving the three wires with spade terminals on the ends
they can be plugged back onto the sender but they need to done correctly
the three wires are
12v ( A - pink/blk) , feed to the idiot light ( B) and power to the pump (C- grey)
simple explanation of operation
its a basically a 4psi dual throw hobbs switch
A and B are a NC switch (normally closed) , so with no pressure A and B have contact (idiot light on)
A and C are a NO switch (normally open) so with no pressure its open (pump off)
once oil pressure rises over 4 psi
A and B disconect (idiot light off)
A and C connect (pump has power)
odds are your connector is shorting the 12v to the pump prime, you dont need to jump it it needs to be disconnected but if the plug has the short just disconnecting it from the sensor ma not fix your issue
if you disconnect and its fine then your sender is bad
ive got a car here that just showed up and it does the same thing.. key on pump runs, but in his case the rubber connector is gone with new spades and its just a case of someone miswired the oil sender.
so you see there was a lot you left out in your initial post as those guessing or offering advice would have assumed this issue just popped up.
the connector to the sender is rubber , the rubber goes goey over time and falls apart leaving the three wires with spade terminals on the ends
they can be plugged back onto the sender but they need to done correctly
the three wires are
12v ( A - pink/blk) , feed to the idiot light ( B) and power to the pump (C- grey)
simple explanation of operation
its a basically a 4psi dual throw hobbs switch
A and B are a NC switch (normally closed) , so with no pressure A and B have contact (idiot light on)
A and C are a NO switch (normally open) so with no pressure its open (pump off)
once oil pressure rises over 4 psi
A and B disconect (idiot light off)
A and C connect (pump has power)
odds are your connector is shorting the 12v to the pump prime, you dont need to jump it it needs to be disconnected but if the plug has the short just disconnecting it from the sensor ma not fix your issue
if you disconnect and its fine then your sender is bad
ive got a car here that just showed up and it does the same thing.. key on pump runs, but in his case the rubber connector is gone with new spades and its just a case of someone miswired the oil sender.
