044 Pump Issue

[GTsauRus]

hahe i love it, thats awesome. As it would be nice to be able to have it lower the flow, and not heat the fuel so much when idling through traffic.

Course... as long as it never accidentally doesn't flick over, and you hit max boost at 7k rpm with low volts and half fuel flow...

that could be ugly, it would go from 13.8v from the relay to 10.5v from the modulator im gonna have a led next to the boost guage to monitor when its on, its got separate adjustable cut in cut out so it can turn on above 8psi and off below 2 psi to make it stable.

[Guilt-Toy]

HOW GOOD!!!

I want.. how do you hook this up to my car? i use AFM ?

ok so it probly is hot fuel you could measure the return temp to prove it.

I ran 8g from the battery to a distro block in the boot because the stock wiring was only supplying 10.5v to the pump so now it gets 13.8v at the pump.

The gtr pumps 270 litres per hour at 14volts and will maintain flow up to 30 psi boost [according to tests done in the uk with a few different pumps]

So its no slouch but in a stock gtr it only gets 10.5 volts max and 5.5v at idle/ low demand, the manual says its to save power but i think the heated fuel in traffic had a part to play in too and 10.5 v is ok at stock boost

I got an adjustable voltage sensing relay from jaycar to connect to the map sensor for the sub meter boost gauge that will switch in a relay on the earth side of the pump at high boost but still allow the modulator to control the pump speed at idle/low loads and keep the fuel cool.

[Guilt-Toy]

oh some more testing done today. drove from the central coast to the end of the freeway and the noise started (tank was close to empty) before i got to the servo it was getting noisy again... put $40 in and then it went back to normal sound and normal a/f ratio's and did not make any noise all the way to work.

So its definatly fuel temp issues.... I am convinced.

[Cubes]

Guilt Toy..

There's definitely something up as on a day like this myself and mates definitely don't have fuel temp/noise issues even when running on empty *red light on*.

Our pumps only start making noise on warmish 30degree+ days.

Have you tried pointing the return away from the pumps pickup? Maybe your aerating the fuel some what which shows up when low on fuel?

[Guilt-Toy]

I am using the stock setup. using the walbro pump to pickup fuel and feed to the 044 then the 044 push's to the front of the car.

I have not changed the pickup or returns at all - its all stock

Guilt Toy..

There's definitely something up as on a day like this myself and mates definitely don't have fuel temp/noise issues even when running on empty *red light on*.

Our pumps only start making noise on warmish 30degree+ days.

Have you tried pointing the return away from the pumps pickup? Maybe your aerating the fuel some what which shows up when low on fuel?

[Guilt-Toy]

I rang John and he has a stock z32 oil cooler runnong on the return line at the rear of his car in the wheel arch with an air duct.

I am going to run one on the return line at the front of the car. Cool the fuel going back to the tank... would think it would be better to run it on the way to the engine as i can see it giving a better burn that way but its under pressure there....

[Guilt-Toy]

have you taken it to sydney traffic ? sometimes you can be at stop start traffic and not going above 30 km's an hour for 30 minutes at a time... I dont have issues when i am boosting around the streets at home its just in very heavy traffic.

Guilt Toy..

There's definitely something up as on a day like this myself and mates definitely don't have fuel temp/noise issues even when running on empty *red light on*.

Our pumps only start making noise on warmish 30degree+ days.

Have you tried pointing the return away from the pumps pickup? Maybe your aerating the fuel some what which shows up when low on fuel?

[Cubes]

have you taken it to sydney traffic ? sometimes you can be at stop start traffic and not going above 30 km's an hour for 30 minutes at a time... I dont have issues when i am boosting around the streets at home its just in very heavy traffic.

I have the same setup, intake lift with the external. Regardless if its an empty tank or full take I still get the noisy pump when the amb temp is warm, empty tank noisy fuel pump then fill up, its quiet for 5mins or so then gets noisy again.

We have a little stretch heading home where you sit jammed in traffic for a good 30mins and you literally move a couple of car positions then sit for another 5mins, this repeats for a good 30mins; the only difference being your lucky to even register a speed on your speedo. I would say its comparable.

Pointing the return away from the pick up is a suggestion that others have said they have had good results with in reducing the noise of the pump on those warm days.

Its only a suggestion that may save you a couple hundred. :S

[Guilt-Toy]

well i can only bring it down to fuel temp. when it makes noise the fuel pump is pretty warm.. this morning after i put half a tank of fuel in the car there was no noises and the pump was cool.

What else could it possibly be ?

[Public Enemy]

sounding more like fuel temp problems, like i said mine does exactly the same. Only thing i don't get is why other people are not having the same problem. Every man and his dog with a skyline has upgraded the fuel pump but only a handful are suffering these problems.

Is it possible we are "over Fuelling" for our power levels. i'm only making 350hp at the wheels at the moment. perhaps i'm pushing to much fuel to the engine bay and just not consuming enough and thus with the large amount of fuel returning to the tank the fuel in the tank just gets to hot.

anyways good luck with the fuel cooler.

[Craved]

i was always thinking of a smal trans cooler mounted up front, might look into a place out the back see if theres room

[Guilt-Toy]

I was told to put it on the return line... but i would love to be able to put it on the other side for performance gains not that it will make much difference

[Russco]

I was told to put it on the return line... but i would love to be able to put it on the other side for performance gains not that it will make much difference

Yes this is correct - use the return line as the pressure is much less. You'll be surprized how effective this is, I run a small Perma-cool power steer cooler on my return line (at the front) and the surge tank is way cooler, no more fuel heating issues for me.

[Guilt-Toy]

yeah thanks sounds like i am onto the right issue...

will try get something on this weekend.

[GeeTR]

Id say it is heat related, maybe the fuel when hotter, cavitates more easily into the pump.

I would say both making the fuel cooler or changing the angle of the return line would work.

Seems strange some people get the issue and some don't. I would have to say, it must be due to small differences in installation angle, depth, running original sock filter etc etc.

[GTsauRus]

HOW GOOD!!!

I want.. how do you hook this up to my car? i use AFM ?

you can use a gtr boost guage sensor, beer baron had a couple of gtr boost sensors for sale a while ago

you could go back to the stock setup [dropping resistor and relay] and wire another one in parrallel for the 044 except connect the negative to your wire direct from the battery

i dont know when the ecu decides to go to high flow, probly airflow or throttle position or both.

[porschephile]

Just thought I'd chime in. I have had the same exact problems with the 044 pumps on my Porsches. After lots of trial, error, browsing the internet, etc I finally determined what was causing the fluctuating whining is heat related. I'm not saying this is necessarily the problem for everyone experiencing similar issues with these pumps. Both of my current Porsches have external pumps, and they are mounted in areas that receive poor cooling and limited airflow. I have noticed with mine that, sometimes they will be relatively quiet and consistant, but usually they start to whine a bit louder and sometimes in a fluctuating manner after I have been driving either car for an hour or 2 and especially in slow/heavy traffic. Voltage fluctuations to the fuel pump are another possibility as well.

[Guilt-Toy]

Okay i did more testing... and i am 100% sure that its fuel temp issues because yesterday arvo the pump was making very loud noises so i pulled into the servo (had low fuel) left the engine running and poped the boot so i could hear the pump and put in 40 litres of petrol.. as soon as i got up to around 15 litres of petrol the noise completly went away and it sounded normal.

So the extra fuel cooled down the system and i could even feel a temp difference when touching the pump.

i am going to try find a decent oil cooler and put it onto the system this weekend and see how it goes next week.

[Cubes]

Guilt-Toy...

So is it the noise your worried about or the afr's going to shit when the fuel pump gets noisy?

Exactly what drivability issues do you experience? Light throttle surge? Idle lean missfire?

As I mentioned earlier (i think) I have been experiencing a few light throttle surge and idle lean missfires. BUT it occurs randomly; most of the time with the fuel pump noisy but also a lot of the time when its quiet. Putting fuel in does make my fuel pump quiet as yours did BUT it doesn't make a difference if the afr's are playing up on light throttle/idle. Does yours?

[Guilt-Toy]

the car was idleing on 17 to 18 afr and when the pump cooled down it went down to around 15.5 (which is still leaner then normal) and it was still missing a little on idle....

on cruise when the pump is noisy it does surge alot and runs pretty lean.. my tune atm is set to around 14.5 - 15.5 on cruise when the pump gets noisy it goes up to 17 +

oh and im worried about both issues because one the noise annoys the shit out of me and 2 the car drives kinda rough when it leans out that much and its annoying too.

Boost is still normal afr's

I have a wideband afr meter in my car at all times now and thats what ive noticed.

Guilt-Toy...

So is it the noise your worried about or the afr's going to shit when the fuel pump gets noisy?

Exactly what drivability issues do you experience? Light throttle surge? Idle lean missfire?

As I mentioned earlier (i think) I have been experiencing a few light throttle surge and idle lean missfires. BUT it occurs randomly; most of the time with the fuel pump noisy but also a lot of the time when its quiet. Putting fuel in does make my fuel pump quiet as yours did BUT it doesn't make a difference if the afr's are playing up on light throttle/idle. Does yours?

Edited May 3, 2007 by Guilt-Toy