P8 pro wiring fuel pump
P8 pro wiring fuel pump
Wondering how the fuel pump relay works does the Ecu give out a signal to keep the fuel pump on? Also I'm running to fuel pump low and high pressure, how would i go about wiring both pump can I just used the terminal and splice it twice thanks ben
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- Posts: 3578
- Joined: Tue Aug 02, 2011 12:08 pm
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- Location: Norn Iron
Re: P8 pro wiring fuel pump
The ecu provides a ground which you will use to energise a relay ( or multiple relays ).
In short, it will be grounded when the ecu sees the crankshaft rotating, and also for a few seconds on key on to prime the system.
In the event of an engine stop ( ie crash type of scenario ) the pumps should stop running
Basically the same way all modern cars operate.
In short, it will be grounded when the ecu sees the crankshaft rotating, and also for a few seconds on key on to prime the system.
In the event of an engine stop ( ie crash type of scenario ) the pumps should stop running
Basically the same way all modern cars operate.
Re: P8 pro wiring fuel pump
So what part of the relay do u out pin 41 to the earth which is pin 30 under din standard? Thanks Ben
Re: P8 pro wiring fuel pump
Earth to ecu, switched live to other side.
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Re: P8 pro wiring fuel pump
Typically terminal 85 is the relay ground. You will wire pin 41 of the P8Pro to this.
Relay terminal 86 would have a switch 12v ignition feed.
Then the fuel pump power in/out across the other relay terminals 87/30, wired/fused as appropriate
Relay terminal 86 would have a switch 12v ignition feed.
Then the fuel pump power in/out across the other relay terminals 87/30, wired/fused as appropriate
Re: P8 pro wiring fuel pump
Thanks alot for the reply helped alot would u recommend the best relay to use is the Bosch one in the wiring diagram thanks Ben
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Re: P8 pro wiring fuel pump
Any generic relay of suitable current rating for your pump will be fine.
Cheap or quality is entirely up to you.
Cheap or quality is entirely up to you.
Re: P8 pro wiring fuel pump
Just a normal 4 pin would be good then, thanks alot for your help 10amp will be the fuse in the pump and using a Bosch 044 and facet underneath the car so i just use two relay same wire on both be sound? Thanks alot for your information
Re: P8 pro wiring fuel pump
I'd go 15A on the fuse - a 044 can pull 11A on occasion!
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Re: P8 pro wiring fuel pump
An 044 will be pulling around 11A operating normally. Higher if higher fuel pressures are used.katana wrote:I'd go 15A on the fuse - a 044 can pull 11A on occasion!
My pair of 044's on startup. ie key on, and then engine start see a current spike up to about 32A only for a split second though.
Then they settle down to about 22/23A, that's at about 47psi actual pressure.
The spike would never blow a fuse, but I'd still be inclined to run a 20A fuse
For a long time I did run a 30A blade fuse, but you could see that it had been heated and melted slightly. Although it was in use for several years.
Ive re-wired things now with a 40A fuse and 70A relay.
But yes you could use a single 30/40A relay and suitable fuse for both pumps.
You could either run both pumps off a single fuse or fuse them separately.