Fuel Pump ST185 ( comeone auto sparky skill ppl )

[Adydas]

Anyone know the location of any and all fuses to power the fuel pump, also any ways to diagnose if the pumps naffed or a fuse has blown that would run it.

Ive taken the line off the rail and turned the key and i didnt get fuel pissing out so im assuming my car wont start as the fuel pumps naffed its self :/ (1 day i had the car, technically 6 hours )..

SEE MY LAST POST..

[rollaholic]

check power is being supplied to the pump when key is on, if not then check fuse / relay, if yes then pump not so good!

[DeeCee]

BGB...

[Adydas]

check power is being supplied to the pump when key is on, if not then check fuse / relay, if yes then pump not so good!

Isnt that what im trying to do? im asking what relays and fuses are between 12v and the pump its self..

ive chekced fuses under the hood, and theres no sign of anything blown are there any hidden fuses im not paying attention to or relays i need to check?

[MrOizo]

you're not really checking it by turning thew key.
some times it needs a signal to start pumping. try putting a test light/multimeter where the FP is and then see if its getting any power when you crank it..

another thing, i remember youo saying you had a new one - did they wire up to ignition or on stock system?

[DocT]

Is it possible the Alarm (if it has one) has fuel cut feature? maybe the alarm is messing up the power supply? Just a thought.

[RunningRich]

Doesn't the ST185 only prime the fuel pump once the flap in the AFM moves (ie, when the engine cranking sucks air in, moving the flap)?

I know that the ST185 RC does not have the switch in the AFM for this so the ECU primes the pump differently.

Hence turning the key isn't enough, so you have to crank or flick the flap in the AFM by hand.

[matt dunn]

Standard ST185's have two fuel pump relays,

there is the standard Fuel Pump relay that turns the pump on and off,
which is probably Green and mounted near the ECU,

but the output from there goes to the Fuel Pump Speed relay which
is in the fuse box under the bonnet in the RHF corner of the car.

I have struck problems with the changeover relay in the front relay box before,

On low speed the power for the pump also goes through a resistor which looks like an injector resistor on or near the firewall area.

All from memory from the one's I have done work on as race cars a while ago, but it should still be correct.

[85AW20v]

Check your dignostic plug as quite often there is a couple of pins you can bridge in there to see if it's all OK. It's marked FP in my AW.

[Lloyd]

As above, bridge B+ and FP and see if you can hear the pump going

[Adydas]

ok just to remind everyone, the car

- No Longer has a factory ECU or Loom
- No Longer has a diagnostic Plug
- No Longer has AFM
- No Longer wired up in any way factory unless the alarm or normal fuses are the issue. The 2 wires that would plug into the factory ecu are Jumpered accross each other so that upon ignition the pump (used) to go full time regardless of the car being started or not.

I need to check these 2 relays tho, but the thing is ive put a multi meter on the back where the pump goes into the tank via the boot and ive checked some wires and some do and some dont generate 12v, my issue is out of the like 8 wires going to 1 fuel pump what out of them are supposed to be live upon ignition, and what are the other 7 (6 if one is an earth ) doing.

I guess some are fuel level sensor for the tank? but what out of the 2 looms do this.

[Adydas]

Ok



From Fig 1

Ive ascertained that the loom on the left with 4 wires is for the fuel guage on the cars dash, so ignore that.

The loom on the right is for the pump unit its self.

4 wires each crimp into 2 pins.

The 2 pins on the right in white / Blue Black when un plugged and a multimeter is placed on the end of the blue black pin and earthed is 0v when you turn the key its 10-12v.

the white is 0v all the time.

BUT if you plug the plug in and multimeter the other end of the plug from the blue black region (where the green heat shrink is ) regardless of the keys position it stays around 0v as apposed to when it wasnt plugged in and it went up to 12vs.

By my understanding that its live 12v un plugged means no relays or fuses are stopping it powering the pump, the question is why it gets no voltage when its connected ( is this a sign the pumps had it? ) or is it a sign of somthing else that im not aware of the workings towards?

In fig2 you can see the "jumper" thats closing the fuel pump circuit, if i unplug that it goes off it should go in via the ecus 2 exposed wires but for reasons i wont bother explaining all you need to know is " it just doesnt, and this is how it is and has worked "..

[Lloyd]

Undo the screws and lift the pump out. There will be 2 wires to it, one for power and one for earth. Cut those off the loom and wire up to the key.

[Alex B]

So how exactly is anyone meant to know the location of your fuel pumps relays/fuses if its not wired up in any way factory?

Your understanding is not quite right, they could well have (and probably have) put a relay on the neg side.

[Adydas]

i want to know and check the factory fuse and relay as from the battery to where the ecu would take over there is still a factory fuse and or relay in place, also possible one between that point as well as alot of the factory
loom and setup has been used but the ecu isnt factory, nor is the diagnostics or the AFM.


Either way im happy 12v is getting to the pump, its just why the pump side of the plug doesnt read 12v...

A sign the pumps gone, or a sign of a bad earth? what?

[Lloyd]

You have power at the plug for the fuel pump? If so, does the other side have an earth? If not then do either of these switch when you turnt he key on or off?


The pump needs 2 wires to go to it, a power and earth. If you want to rule the pump out as being the issue then feed it a known good power and earth and see if it goes

[Adydas]

are the 2 white wires as shown in my pictures on the loom into the fuel pump earths or somthing else? So 12v directly into the pump side of that loom ourta do it then ay?

[Lloyd]

Undo the screws and lift the pump out. There will be 2 wires to it, one for power and one for earth.

[matt dunn]

are the 2 white wires as shown in my pictures on the loom into the fuel pump earths or somthing else? So 12v directly into the pump side of that loom ourta do it then ay?

White with a black stripe is high current earth on toyota,
Just like brown is sensor earth.

So in your fig one, the blue is ( should be ) power to the pump,
and the white/black is earth.

What was done with the fuel pump speed relay when the link was wired?
as by default they are on low speed unless you power the relay I think?

[Adydas]

i THINK ( supportd by FIG 2)that the relay MIGHT have been jumped over or past, normally the lines would go into the stock ecu and have some form of control over them.. But in fig2 you can see right where the I for FIG is, there is a white wire with 2 spade terminals jumpering the 2 wires that used to go into the ecu.

With your confirmation that the pumps power is suppled via that Blue and Black thick wire, i feel confident power is getting to the pump but the pump is failing to operate even with 12v, i have checked with the mulitmeter its got power and ive removed the fuel line from the rail and "powered" the pump on hoping to sight a flood of fuel spurting out of the pipeing that should be connected to the rail.

Pisser as the pumps 3 months old, and the car has done 633ks on it.... sucks to be second hand pump with no warrenty.

Anyone now know how to remove a fuel tank and pump from a ST185?