Intercooler Pump Prob

**Roundy** · 12-01-2006, 08:49 PM

Hey guys,

Got a bit of a strange one.
My intercooler pump (Davies Craig Booster Pump) isn't working the way it should.

When the ignition is on but the engine isn't running it pumps beautifully, causing turbulence in the cooler.

However when i start the motor its pumping stops...or slows RIGHT down, not 100% sure which.

It was wired up by the previous owner so i am not entirely sure how it is wired in, but only switches on with the ignition in the 'on' position.

Only thing i can think of is that it doesn't like 14.X V...tho the daives craig specs say that it can go to 15 V no probs.

Any ideas?

Thanx Nathan

**Thomas** · 13-01-2006, 12:28 AM

First thing I'd do would be to whip out the old multimeter and check to see that the pump still gets the required voltage once the car has started since it is electronically driven.

mic* · 13-01-2006, 12:51 PM

Sounds like its been wired using the closest/easiest possible power wire with no regard to the load on whichever circuit the power has been scabbed from.

**Ben Wilson** · 13-01-2006, 03:03 PM

It doesn't have some sort of speed controller in there does it?

**Toycrash** · 14-01-2006, 01:31 AM

Does it have EWP controller?
It is an optional controller for the pump. Drives the pump by feedback from temperature sensor. So when it does not need to cool, it does not pump.
Actually it varies pump supply voltage and therefore pump speed.

And if it does not have this, the fault may be wiring thingy as said before.

**roadsailing** · 14-01-2006, 01:44 AM

I have ghetto wired a radiator fan that did something similar to this,

accessories on, fan on, engine running, fan goes off.

not good!

just check with a test light or multimeter if the power source it is connected to stays on when the engine is running, and if not, wire it up again with something you know will stay on (us this to trigger a relay powered from the battery so you dont damage anything) could run it off the fuel pump trigger for example.

**feral4mr2** · 14-01-2006, 12:00 PM

could be as simple as adding a relay to run the pump properly from it's ignition trigger.

**Roundy** · 15-01-2006, 07:58 PM

hmmms no controller at alll...it just runs on or off.

will have a look at it again soon (been at the dyno day all weekend and no access to multimeters and what not)

It has a lil box of connectors for it with 4 wires coming to/from it

one wire is from the battery, another wire is the earth, another goes to the pump and another anonymous one. If i pull out the anonymous one the pump stops working altogether...so i think that one COULD be causing the problem, now just need to find out where it goes to!

**feral4mr2** · 15-01-2006, 11:01 PM

thats a relay. the anonymous wire will be the trigger, yea find where it goes and see what curciut is being used to trigger it.

i have my EBP for the w2a triggered from my unused a/c idle-up wiring, works great.

**EldarO** · 15-01-2006, 11:50 PM

hook that anonymous one up to the positive terminal on your coil, sorted, this will tell the relay to send 12V to your pump when the keys are in the "on" position.

Eldar.O.