Anoth Fuel Pump Question

[Johnnybizzle]

Hi, Guys,

My bike engine an loom originally had no fuel pump, but now using a fireblade pump which ive put close to the tank. My question having limited knowledge of electics is where does it need to be connected to the loom to turn on when ignition is turned on also been told 5 amp cable and fuse is enough,

Any help appreiciated, gotta get some supplies for next weekends 'get it started Mission'

regards Jon

[twinturbo]

You will want an inertia cut off,

Is there an ECU on that engine that controls the pump? if not your probably best fitting a tachimetric ( spelling? ) fuel pump relay.

TT

[Johnnybizzle]

TT,

The fuel was gravity fed carbs, ive been told that these pumps cut out when fuel pressure builds up.

where will i be able to get a relay from?

thanks for fast response

JB

[twinturbo]

A pump relay for a car running Bosch K-Jettronic ( 16V Golf, Early Audi 80's and 100's , XR4i) also Peugot GTi's had them I think.

The Tach relay senses ignition pulses and cuts the fule supply when the inition pulse goes dead.

You an get a good inertia cutoff from the engine bay of a rover 200, or from a sierra EFi ( wheel well up to 1990, drivers kick pannel 90> )

TT

[deezee]

What's the result of wiring the Fuel pump to come on when the ignition is on? This is how mine is currently set up (On kwacker bike carbs)

[twinturbo]

Well if you have a crash and the fuel lines rupture then you will just pump fuel everywhere and end up engulfed in a fireball.

And with a Tachi, if you fuel line splits then the engine will die and cut the fuel.

Personaly, fitting a tach or inertia cutoff seems like a reasonable precaution.

TT

[deezee]

Right OK. Suppose its not going to help much with a fuel leak because the carbs would have to run dry before the engine cutting out stops the pump. See what you mean about a crash though, doubt anyone is going to try an pull me from my car if its covered in petrol!

[Johnnybizzle]

DeeZee,

how and where did you wire up the pump to the ignition??? had a look today, totally lost with it, project get her fired up was stopped by flat battery, goin to wire it up as temporary measure and and take advice from TT and add a relay as and when i can get one.

[deezee]

I'm using the donor Sierra relay/fuse box. I stripped out all the useless wiring (heaters,wipers,stereo,interior lighting etc) and removed the redundant relays and fuses from the box. The fuse box, despite being off a carbed 1.8cvh, actually contains the wiring for the fuel pump off an EFI model car. I just made it live again by providing a feed (black with a red stripe I think?) and re using a, now unused, relay.

[twinturbo]

Note: The sierra fuel pump relay is just a power relay. It should be used in conjunction with the inertia cutoff.

TT

[dogwood]

Hi TT.

Not to hyjack the post, but.
Do I read right, that I need the inertia switch in the boot to cut off the fuel pump when the engine is running? (To stop over fueling)
I didn't take it off, coz I thought it was only for cuttoff in case of a crash.

Cheers

[twinturbo]

The inertia switch is in case of a crash where the engine remains running. On the eec-iv if the engine stops the ecu kills the pump relay, on some cars there is an external RPM sensing ( tachimetric ) relay that needs a ignition pulse or it cuts the fuel pump.


I am not sure what the IVA manual states.

Your probably not going to over fuel so long as you have a preasure regulator and return.


Remember also that the pump ( certainly injection ones ) draw quite a few amps, and if left running on a stoped engine will drain the battery.

TT

[Bonzo]

I may as well have a little highjack myself :o

TT
Do you know if the fuel pump relay controls the initial prime of fuel or is this a function of the eec iv

Let me explain a bit better . when you turn on the ignition, normaly you hear the fuel pump prime the system, I assume that the pressure is sensed somwhere & when up to pressure the fuel pump cuts out. :confused:

The reason I ask is because I did not save the Escorts fuel pump relay :o

[twinturbo]

It's a basic relay, pump control is from the ecu.

If you ever think you have flooded the engine, depress the throttle all the way and the ecu will not fuel during cranking, purging the cylinders.

TT

[Bonzo]

All good then :)

I'll grab a handful of relays next time I am at the breakers ;)

Soon be ready to rig up the engine for a test fire .... Very much looking forward to that day :D :D

[HandyAndy]

Soon be ready to rig up the engine for a test fire .... Very much looking forward to that day :D :D

nice one Ronnie, & don,t forget the video of the great occasion :cool:

cheers
andy