Fuel pressure/flow problem Push turbo M8

[sweperformance]

Hello..!!

I have some problem with my push turbo m8.
I`m running on pumpgas and 8 psi boost.

Adjusted the in tank fuel pressure regulator (1:1 BDX) to 38 psi on idle. It should now rise the pressure to 46 psi with 8 psi boost, but it only goes up like 2 psi, I can even se a dip on the pressure on some rpm.

After this I adjusted the pressure manually up to 50 psi. On full trottle the pressure goes down to 47-48 psi.

If I put 10psi pressure on the regulator on idle, the pressure rises 10 psi as it should.

I have tried two different BDX regulators and two pumps, same thing. The stockpump can deliver more fuel pressure/flow than this, im sure!

Any ideas?? next step for me is to connect a return line on the fuelrail and then connect a external regulator to the returnline.

 

[Radski30]

Hello..!!

I have some problem with my push turbo m8.
I`m running on pumpgas and 8 psi boost.

Adjusted the in tank fuel pressure regulator (1:1 BDX) to 38 psi on idle. It should now rise the pressure to 46 psi with 8 psi boost, but it only goes up like 2 psi, I can even se a dip on the pressure on some rpm.

After this I adjusted the pressure manually up to 50 psi. On full trottle the pressure goes down to 47-48 psi.

If I put 10psi pressure on the regulator on idle, the pressure rises 10 psi as it should.

I have tried two different BDX regulators and two pumps, same thing. The stockpump can deliver more fuel pressure/flow than this, im sure!

Any ideas?? next step for me is to connect a return line on the fuelrail and then connect a external regulator to the returnline.

Are you running Guages (A/F and Boost Gauge) off the stock fuel pump circuit?

 

[product tester]

the stock pump is only good for 7 #s of boost max I recomend 6.

 

[Woody67]

the stock pump is only good for 7 #s of boost max I recomend 6.

Shain how do you guys determine how/when the stock fuel pumps and injectors max out?

Thanks,
Woody

 

[everytime5.9]

A simplistic way of telling is by the gauges. Too small of a pump you will start dropping pressure on a long climb, for the injectors the duty cycle being operated too high. Duty cycle referring to how often the injector opens/closes and usually shouldn't exceed 80%. It can be numerically calculated by knowing what the pump puts out and what the injectors flow for a given amount of time.

 

[sweperformance]

My friend is running his asphalt dragsled with the same fuel pump but with a external regulator. (not turbo, Price 1000). We can see in the dyno that the pump puts out mutch more flow and pressure??!

 

[mmsports]

Call Ray at BDX

Just give them a call not sure what to tell you are you shore that the line going to regulator is not pinched sounds lick maybe it is vacuuming instead of pressuring.
BDX.507-824-9966


Woody how you tell your duty cycle on a attitude box is by watching the colors and if it maxes then so does you fuel from what I understand correct me if I am wrong Shane.

 

[product tester]

I think your right kev but I had it hooked to a dyno with a scope hooked to the injectors ,I found this out by going riding and changing one thing at a time. till the problems went away .
like radski said check the voltage to your pump.

 

[minecat]

I am having the same issue with my TM1000 I am also using the BDX pump and regulator I verified the voltage and it is normal 11.8 at idle and goes up to 14 when given throttle. My pump is wired into the acc. outlet and my AFR gauge is wired into the stock pump outlet (How is yours wired) I am seeing a bigger drop in pressure starts at 40 and falls to 30 while climbing and after I turn out while coming back down the pressure will come back up but fall again after a couple of seconds and stay there until i burp the throttle. I have pulled the reg and inspected all good have checked the boost line to the reg and is good, as you said when when pressured up it works properly in shop at a idle, I am going to try a new pump to see if that is it and if it is not I am going to put a 12v battery in and hook to pump to see if that fixes it I really hope that my stator is not bad as I have had 2 bad ones already will let you know what i find.

 

[sweperformance]

The BDX fuel pressure regulator is the problem! Running a Mallory Ignition 4305M regulator outside the tank now, no problem with the fuelpressure, 8lbs boost, 205hp/140torque.

No problem with flow from the pump, waste of money to replace it on pumpgas kits.

I`m running my pump on stock connection..!

 

[product tester]

The BDX fuel pressure regulator is the problem! Running a Mallory Ignition 4305M regulator outside the tank now, no problem with the fuelpressure, 8lbs boost, 205hp/140torque.

No problem with flow from the pump, waste of money to replace it on pumpgas kits.

I`m running my pump on stock connection..!

you are right the stock pump seems to really lose pressure at 210 hp so 205 would be close to death I have also heard of re wireing the stock pump for more flow.

 

[minecat]

The BDX fuel pressure regulator is the problem! Running a Mallory Ignition 4305M regulator outside the tank now, no problem with the fuelpressure, 8lbs boost, 205hp/140torque.

No problem with flow from the pump, waste of money to replace it on pumpgas kits.

I`m running my pump on stock connection..!

Did you take the BDX regualtor apart to see what the problem might be with it did the BDX reg ever work, only reason I ask is because mine is doing the same thing but there doesnt appear to be anything wrong with the reg once inspected. When you went to the external reg how did you block the return off in the tank

 

[sweperformance]

Did you take the BDX regualtor apart to see what the problem might be with it did the BDX reg ever work, only reason I ask is because mine is doing the same thing but there doesnt appear to be anything wrong with the reg once inspected. When you went to the external reg how did you block the return off in the tank

Yes I took it apart, nothing wrong with the reg. Tryed two different pumps and two reg, same problem.
I blocked the return on the BDX reg with a screw, so the pump gives max flow/pressure. (the BDX reg is still on the pump in the tank but put out of work).

I did also change the rubber hose inside the pump to a little longer one (1"), this can be a problem on some stock pumps.
Installed a external reg and drilled the return into the tank, works good!

The construktion of the BDX reg seems to be the problem, I can`t think of anything else.

 

[jgw50]

Anyone else had problems with the BDX regulator? They usually make good stuff, I was planning on "upgrading" to the BDX, but looks like i'll be going with the Mallory 2222 return reg instead?

Probably room for another thread here.

 

[minecat]

Yes I took it apart, nothing wrong with the reg. Tryed two different pumps and two reg, same problem.
I blocked the return on the BDX reg with a screw, so the pump gives max flow/pressure. (the BDX reg is still on the pump in the tank but put out of work).

I did also change the rubber hose inside the pump to a little longer one (1"), this can be a problem on some stock pumps.
Installed a external reg and drilled the return into the tank, works good!

The construktion of the BDX reg seems to be the problem, I can`t think of anything else.

Thanks for the information, have purchased a new mallory reg and BDX sent me a new pump going to try the new pump first but I am tyaking the new reg with me to the mountain if it acts up I will just replace while i am out there.

 

[sweperformance]

I installed the extern reg a little different. I welded a return line on the fuel rail where I connected the reg. The return on the reg goes to the tank. Now I have full flow to the fuel rail and adjust the pressure after the fuel rail. This should work even better, maybe a little overkill

 

[jijohans]

Have the same problem on my BD PG 08 m8 running 6-7 psi @ sealevel.
When doing long pulls (35-40sec) the AF meter starts to climb..
Was thinking that the "non return" fuelrail/system could be the problem.
Do you have pictures of your install? Hard to weld on the OEM fuelrail?
Have the fuelpump and oil pump on the "fuelpump circuit" and a AEM AF and fuelpressure gauge thogeter with the BD box/EBC on the Aux outlet.

Have bought a walbro 255 pump and 875cc inj. if the the fuel rail mod does not work..

 

[mmsports]

Fuel psi

I have just the opposite I have to much pressure on my kit I have had to turn it down to 30 psi but this is on my 2010 m8.

 

[jijohans]

And then comes the question, what is the standard fuel pressure? Mine reads 43-45 @ idle.

 

[hatchers]

Shain how do you guys determine how/when the stock fuel pumps and injectors max out?

Thanks,
Woody

trail and error, this is what the quality turbo builders do.....others just box some parts up and ship it