Stock fuel reg or not with a turbo Apex

[rat4020]

I have a 2008 apex with gt2860rs and I have been running the stock fuel rail reg . The problem I been having is when I it builds boost it leans out and the last time runnin it I basicly had to loosen the waste gate to run it home with no more than 2 ta 3lbs of boost and then it would not rev past 9g .I did hook a gauge into the fuel line and its at 43lbs & my pump is a intank walbro 155lph pump.

 

[mbarryracing]

43 is around spec base fuel pressure so sounds like your intank fuel pump is fading... can't maintain volume with an increase in pressure (rising rate), and a fuel pressure regulator can only do so much to overcome a weak pump.

Stock pump should be good for atleast 6 psi if not more with the stock FPR.
I don't think it's your stock regulator, I used mine up to 20+ psi and only replaced it because it eventually stuck closed and was causing over fueling.

I also had a pressure fading issue with a stock pump in my tank when the fuel got warm (resistance went up, operation went down...)

 

[rat4020]

43 is around spec base fuel pressure so sounds like your intank fuel pump is fading... can't maintain volume with an increase in pressure (rising rate), and a fuel pressure regulator can only do so much to overcome a weak pump.

Stock pump should be good for atleast 6 psi if not more with the stock FPR.
I don't think it's your stock regulator, I used mine up to 20+ psi and only replaced it because it eventually stuck closed and was causing over fueling.

I also had a pressure fading issue with a stock pump in my tank when the fuel got warm (resistance went up, operation went down...)

Thanx for the reply : I am gona be removing my tank tonight to fab up a sump in the bottom as well as removing the pump .Whats funny about the pump man there aint but 60 gal of gas run through it in two years . As far as the pump goes ,do ya think I should replace it with a 255lpg and keep it in the tank .

 

[mbarryracing]

Like I said I deleted my intank pump because of inconsistentcy and went with an external Bosch 044, I talked about it my one thread http://www.ty4stroke.com/threads/fp...-up-with-motec-and-other-tricks.122186/page-2.
I hear what your saying about the pump being fairly low hours, doesn't mean it didn't run dry at some point and that hurt it, finally degraded to the point it can't maintian volume (remember volume and pressure are two different things). Guess the only real way to dispell it is to put a fuel pressure gage on it that you can read when on the boost. It had better be raising atleast 1 psi from 43 base for every psi of boost pressure.
FYI I also smoked an external pump because I was basically running it dry at every start after it sat because I didn't have a fuel flow check valve in the system (could hear it)... My external pump is mounted in the nose of my sled, down low and found it would syphone drain back out of the pump and back to the tank, eventually it effected how that pump operated. I have since installed a flow check valve in line between the pump and tank.
So unless you have a built in flow check valve in your in tank pump, you might be starting it dry everytime???

 

[rat4020]

Like I said I deleted my intank pump because of inconsistentcy and went with an external Bosch 044, I talked about it my one thread http://www.ty4stroke.com/threads/fp...-up-with-motec-and-other-tricks.122186/page-2.
I hear what your saying about the pump being fairly low hours, doesn't mean it didn't run dry at some point and that hurt it, finally degraded to the point it can't maintian volume (remember volume and pressure are two different things). Guess the only real way to dispell it is to put a fuel pressure gage on it that you can read when on the boost. It had better be raising atleast 1 psi from 43 base for every psi of boost pressure.
FYI I also smoked an external pump because I was basically running it dry at every start after it sat because I didn't have a fuel flow check valve in the system (could hear it)... My external pump is mounted in the nose of my sled, down low and found it would syphone drain back out of the pump and back to the tank, eventually it effected how that pump operated. I have since installed a flow check valve in line between the pump and tank.
So unless you have a built in flow check valve in your in tank pump, you might be starting it dry everytime???

I have a feelin that it is my fuel pump . Before I made my Turbo setup I was runnin the stock fuel pump with the artic cat (Smart valve) pickup's in the tank and even with one on each side of the tank it would suck air when taking a hard left turn with less than 1/4 tank . When I replaced the stock pump with the Walbro 155lph pump I used the pickup sock that came with the Walbro pump and then it would suck air if I ran the tank below 1/2 and did the hard left turns .

It aint hard to replace the Walbro 155 intank with the 255lph being I made the plate with a place to mount the pump onto in the tank ,to take the place of the stock pump already . But I am gona put the pickup sock into a sump that I am building into the bottom center of my tank . That should take care of the fuel void problem or suckin air !

As far as starting it dry , as a rule I never would try to start it untill the pump would quit but that does tell me that the gas is bleading back . And I do like your idea of a flow check valve along with the stock reg bypass plate I am gona get both of those to add . I do have a Summit rising rate fuel regulator with a gauge on it that I would like to install in place of the stock fuel reg and plumb the gauge onto my dash

 

[mbarryracing]

What i meant by starting dry is not actually starting the engine, what I mean is the fuel pump is starting dry with air inside when it first powers on because the fuel has drained out of it so then it cavitates for a few seconds before priming and then eventually loads down pumping fuel.
The fuel pump triggers via a prime cycle in the ECU, which keeps it on for only a few seconds at key. There is no sensor that turns it off when there is enough pressure, it's on for a set time unless it senses oil pressure (engine running).
The fuel lubricates the pump and also cools it. You'll hear it because it will hum and whine or scream for a split second then you'll hear it load down when it starts pumping fuel.
I got a nice rather inexpensive black check valve from JEGS, their brand. AN fittings on the ends and put barbed adapter fittings on so I could clamp on the fuel line.
If we are going to boost a machine and intend on using the stock pump, if at any time it happened to have run out of fuel (pump running with no fuel in it) then we will replace the pump as a precaution because that really weakens them. Sounds like you weakened your pump for sure.

 

[rat4020]

Mbarry thanx a bunch for your help .. Time to cut a hole in my tank and weld & order up some parts
One more question for ya .. Is it possable to hook up a AME afr gauge along with my autotune PCV

 

[mbarryracing]

rat4020
not really sure about the AFR gauge. I have the white output signal wire from my AEM gauge going to my MoTeC but not totally sure on the PC.
Were you looking to use the gauge to signal the PCV?

 

[rat4020]

Could you still use the auto tune ? I guess what I want to do is get rid of my LC200 screen and use a AFR gauge in its place and wire a switch for switchin maps . The LC200 screen is a pain for me to read & use I just want gauges I can read and depend on

 

[FLYBYU]

I run 2 pumps in my system. Stock pump in tank to fill surge tank and high pressure to fuel rail. I dealt with this the other year. Leave gauge in it. You should be able to just turn the key on and it should build 43 p.s.i. The question is does it hold?????? If it doesn't hold pressure that's a bad fuel pressure regulator. It should hold for a couple hours. That's where I'd start with that. I've seen check valves in fuel pumps go bad also. You can check that by pinching line after gauge but before fuel rail and just turn key on. Again if it doesn't hold on this one it's your pump. JUST MAKE SURE ALL YOU FITTINGS ARE ALL TIGHT ON THIS TEST. YOU WILL MAKE ALOT OF PRESSURE IN THE FUEL LINE

 

[rat4020]

Thanx for the reply FLYBYU Good info
I took my tank out and started my sump tank
My tank

cut out for the sump in the bottom

The sump


Hers were its gona be I dont have but 1 1/2 of room below the tank but I figure its gota be a hell of a lot better than before

Im gona wait till my new pump shows up before finishing the pump mount cause I am switching from a 155lph to a 255lph and my luck would be if I made it to fit the old pump the 255 would be different

 

[FLYBYU]

I have the impulse fuel tank and surge tank. Surge tank sits down in front of battery

 

[FLYBYU]

 

[rat4020]

Heres what I came up with for surge tank control
These are the flaps

 

[gsxr]

My setup is 2011 Apex 295hp at 14 LBS , no pump in the tank, Mcx has a nice in tank pickup and a suitable external pump kit , mounts easily , no cutting needed ! Prince George Yamaha , or Ulmer will have it !