1294 replies to this topic

[Matt]

You're a machine man. Ha ha.

haha theres shit to do and i just do it:)  

Shits tidy yo

Cheers brutha!



Ok...so swapped out the old DW300 pump for the new Walbro 460 this arvo

Fairly painless install...not as tidy fit as the DW pump but lol

Just required a tiny bend to the lower bracket as the pump is so long its a tight fit!

Being an E85 proof pump i had to rewire some sealed connectors to do it properly..easy as

Came out good i think!

The pump will come back out in a week or two anyways when i get the STi anti slush box from the US

Pumps a bit noisier on full load...not much but? I did have the seat off and the hatch off to check for leaks though

Quiet as on idle though

The cool thing was that after install i primed the system and tried to start it and it turned over the first try lol

Normally it takes 5 to 10 goes for the first start of the day haha

Its obviously because the pump is making the tune richer and in turn making the start rich. ..fingers crossed it stays this way after the retune

And one lesson learnt today...depressurise the fuel tank before undoing lines lol, I completely forgot hahaha

Fuel everywhere!!

Cable ties are my friend


Nice and tidy patch lead


and done...with another cable tie or two lol


now i just gotta wait on a date for another try at a tune from Mick

[Liberty]

That's not a bad thing at all man. Top stuff.

[RX25SE]

And the pump now only pulls 6.1A at idle compared to 7.8A earlier

 

 

i even had the kyoritsu clamp on ammeter out on this job aswell

 

How good are current clamps!

 

 

How come the pump pulls less current after you fixed the voltage drop? Normally when more work is done (pump working harder) the current draw increases?

 

Ohms law.

 

 

 

Here is a scope screen shot I took of a current draw test on a VR Commodore with the return line clamped to simulate a blocked fuel filter (bad for the pump I know )

 

 

Normally the pump pulls under 5A but you can see that when it has to work harder to overcome the blockage the current rises to over 6A.

 

Blue trace is voltage at the pump and it remains constant, blocked or unblocked.

Red trace is current, due to the short time base you can see each commutator switching (bumps).

 

 

 

?

[LPM_B4]

Hey Matt do you have a link to the STi surge box for the sock or did you buy it second hand?

I know you can buy the whole pump assembly with it on japan parts but not just the box. 

[RX25SE]

The pump will come back out in a week or two anyways when i get the STi anti slush box from the US

 

I assume this works like a swirl pot to keep fuel at the pump inlet at all times?

[Matt]

All the US sti imprezas come with them stock

So i bought an assembly from the US



Sort of Jas....helps to keep fuel at the pumps inlet on hard right hand turns...and the return and syphon pipes go directly into it aswell helping further




And yep i dunno Jas...i understand in a direct wired system Amps should have increased....can only assume that the ECU saw that it didnt need to work the pump as hard to achieve the same fueling?

But thats what it did

[Matt]

Looks like this Jas



only really needed when pushing the car on a lower fuel level...like 1/4 etc


If you keep the fuel topped up you should never have the issue

im yet to feel it...but i dont wanna either so im trying to add a bit of security

[allpaw4]

The voltdrop will make the pump work harder on its own, so once you remove the voltdrop, it's not working as hard, hence the lower current.

[Matt]

can only assume that the ECU saw that it didnt need to work the pump as hard to achieve the same fueling?

  

The voltdrop will make the pump work harder on its own, so once you remove the voltdrop, it's not working as hard, hence the lower current.

Yep basically i "THINK" the car is aiming for a specific afr.....with the pump supplying more fuel yhan before its seeing its richer and in turn not asking for as much fuel to maintain its stable idle

[duncanm]

Yep basically i think the car is aiming for a specific afr.....with the pump supplying more fuel yhan before its seeing its richer and in turn not asking for as much fuel to maintain its stable idle

err.. don't think so.

Fuel controller just has a low/mid/high duty cycle setting based on throttle (and presumably load).. feed fuel pressure varies by a fair bit (70 - 100psi ?), (returning) fuel reg controls pressure to a fixed number (~40psi std), injector duty cycle controls afr.

The regulator relies on the pump being able to supply excess pressure at the required flow rate, and bleeds off the excess back to the tank to maintain the fixed 40psi. A bigger flow aftermarket pump makes zero difference at idle.. and is there to ensure enough headroom at max fuel rates (which for your E85, are significantly higher than stock).

That's unless you have something like an aftermarket rising rate reg, which will alter pressure at injectors relative to manifold pressure.

[Matt]

Yeah im only trying to think about what its doing...im no mechanic lol

I do have an adjustable fpr in now....i thought the stock fpr was a rising rate aswell? Something like psi for psi rise compared to map?

All i know is it dropped my idle amps down more than 1.5A

I know for a fact my idle has richened up quite a lot simply by putting this pump in...this can be seen or smelt at the exhaust and noticed with the stupid easy start now

[RX25SE]

The way I see it is the voltage drop is caused by a resistance in series between the pump and ground or the pump and battery. If the resistance of the voltage drop is added to the resistance of the pump, then the total resistance of the circuit is now higher than the resistance of the pump alone.

As current is inversely proportional to resistance, then the current should be greater after the drop is repaired.

 

The simple answer is, your car is a freak Matt.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Or the pump controller backed things off.

[Matt]

I do know the controller only controls in 33, 66 or 100% adjustments

So i dont entirely know why it dropped it off? I was just trying t make some sense of it is all

Simple matter is though....i don't really care lol

It was just an interesting thing i noticed and thought id share was all


I was just thinking about the pump was flowing less at say 33% due to the volt drop...and in turn the injectors were opening up more to maintain idle

Now at 33% the pump has more oomph...so the injectors can squeeze in a bit and in turn the pump doesnt have as much load on it

As said im more than likely wrong...that was just my thought process...hence why i started it with "i think" ...not i know lol

But it could have just had to do with fuel temp...or hell even the fact that now theres only one fpr in the loop where before there was two

I really do not know lol

[Matt]

The way I see it is the voltage drop is caused by a resistance in series between the pump and ground or the pump and battery. If the resistance of the voltage drop is added to the resistance of the pump, then the total resistance of the circuit is now higher than the resistance of the pump alone.
As current is inversely proportional to resistance, then the current should be greater after the drop is repaired.
 
The simple answer is, your car is a freak Matt.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Or the pump controller backed things off.

And yes i fully agree with this...and understand it.....i think this would only play a part on a pump free spinning unloaded though wouldnt it?

Once you ask the pump to do work...and that work is ever changing...the game changes a bit

[duncanm]

I know for a fact my idle has richened up quite a lot simply by putting this pump in...this can be seen or smelt at the exhaust and noticed with the stupid easy start now

maybe the previous pump didn't provide enough flow at idle (pwm) voltage to keep the reg over pressured? The stock fuel controller at idle supplies ~8V. Seems weird, given it was 'new'.

.... and I think you're right about the std FPR.. it might be 1:1 with manifold pressure and aftermarket are > 1:1 ?

[Matt]

Yep i dont know...we did test fuel pressure before all these changes and it seemed fine to Mick

I never had issues with idle or anything....and putting the new wiring on the dw300 made no diff to idle feel or cold starts...just had the drop in amps

but put the new pump in and you could instantly feel the change

Im clueless though as this is still a fairly new world for me lol and im open to any info people like yourself can shime on it

Purely out of interest mainly





And there was definitely always a great deal of fuel pumping out the return on idle...even before all these changes

That shows the reg is over pressurised and returning fuel to control pressure right?

[RX25SE]

I do know the controller only controls in 33, 66 or 100% adjustments

 

My 3.0R-B does the same, as do most cars with a non return system.

 

PWM brothers yo!

 

 

 

 

 

It was just an interesting thing i noticed and thought id share was all 

 

Glad you did, as I find this type of stuff interesting.

 

 

 

 

 

 

And yes i fully agree with this...and understand it.....i think this would only play a part on a pump free spinning unloaded though wouldnt it?

 

I know you are all over this (I could tell by the type of multimeter you have ) and you are correct, an unloaded pump will draw less current. That VR scope pattern above will drop to well below 4A when the tank starts running dry.

[Matt]

PWM ftw! Makes for nice quiet pumps at idle

Does the 3RB have a non return system? Or were just using that as an example?

[RX25SE]

I think it does (I can't remember).

 

Most new cars do as it helps to reduce evaporative emissions as the returning fuel is warmed by the heat of the engine, plus by reducing the current to the pump, it takes load off the electrical system which helps reduce fuel consumption and therefore further reduce emissions.

 

It's all about emissions with modern cars....

[Matt]

Ah ok ..always wondered why a lot of cars went returnless!

See this forum is full of awesome knowledge