[UNLIMITED_DIESEL]

We have a truck in the shop that has dual SD fuel pumps inline. Fuel pressure is set at 80PSI. Driving down the road in the stock setting of the chip it goes down to about 50PSI. In the 140 Setting of the chip it goes all the way down to 30PSI. The tank has been dropped, sending unit is clean. New fuel filter has been installed. For the guys that are running this setup, what kind of fuel pressure is normal? We run Aeromotives, so I am unfamiliar with this setup. When the fuel pressure drops, things get real hot, like 1400*+ truck only, and that is not good when all this truck does is pull a trailer around. I think that if we could keep the fuel pressure stabilized that maybe the temps would not rise as fast as they do. When cruising down the freeway at 70MPH, the fuel pressure stabilizes to about 75PSI and only comes down to about 65-60PSI when pulling a hill. It seems to have the biggest problem with leaving a stop sign. Any help would be great guys.
Thanks,
Nate

 

[Bartman]

We're getting ready to install a second SD fuel pump this weekend on a truck, so results are coming.

 

[02Bluestroker]

I would try and lower the base pressure and try and watch what happens then.... try 62-64 lbs base pressure.... it shouldnt need more than that... any time pressure goes up, volume goes down... so if you start with a lower base pressure it should be more stable all across the board...

 

[thetonka]

I may be wrong but if the pressure is dropping because of lack of flow volume having them in series is not going to help. Putting them in parallel will help keep the pressure up at high demand.

 

[UNLIMITED_DIESEL]

If we ran the pumps in parallel, where would you install the supply line in the fuel filter housing?

 

[Fast_Ashley]

If we ran the pumps in parallel, where would you install the supply line in the fuel filter housing?

Don't you have to ditch the fuel bowl for a dual pump set-up??

 

[strokin_early_99]

Fuel supply "Y"s are available most performace shops. Aeromotive has one for $80. I got one for my bowl delete system from summit racing.com for $24. Run the two paralled lines to a Y and then the Y to the bowl. You might try drilling out the center of the 1/8" NPT fitting out to .250 like I did.

Unless I am missing something here, it is that easy.

Keep Strokin'

 

[389SixPack]

Agree with above, the pumps must be in parallel not series. In series, you only get the flow of one pump. You can "Y" them in or just put tees in the lines before and after the pumps.

 

[gregrob]

If i'm not mistaken, most people run one feeding the other ???

 

[Short Bus]

If we ran the pumps in parallel, where would you install the supply line in the fuel filter housing?

they wont work in parallel, one pump will starve the other pump and burn it up. I tried it quite awhile back and it was worse fuel pressure than a single stock pump. right now im running 2 stock pumps in series and it will hold 35 psi at wot with 275's. Yes i know thats not good, but it works for now.l

 

[BCT]

good god why bother with spending the $200+ on the second SD pump. Just get a bigger Boche pump and dump the stocker all together. IIRC the stock SD puts out 35gph @ 50psi? Do some research boche makes bigger pumps with 4x the flow for almost the same price. The one in a delorian puts out double easy and still fits in the stock sleeve.

or get a fass and dump the stock bowl and pumps. YAY!

 

[gregrob]

Dennis at ITP has a good option for a bigger pump too.

 

[Short Bus]

good god why bother with spending the $200+ on the second SD pump. Just get a bigger Boche pump and dump the stocker all together. IIRC the stock SD puts out 35gph @ 50psi? Do some research boche makes bigger pumps with 4x the flow for almost the same price. The one in a delorian puts out double easy and still fits in the stock sleeve.

or get a fass and dump the stock bowl and pumps. YAY!

got a pn for the bigger bosch? I was planning on doing a fass soon, but im open to cheaper options

 

[thetonka]

IIRC its 044 for the bigger pump. Thats what I want to do but also put in a lift pump and move the high pressure pump closer to the engine with no fuel bowl and a bunch of other stuff. Not that I am going to do it now, but I can dream.

 

[gregrob]

That's the one jtharvey is using
http://rides.webshots.com/photo/2593953640089903167JISjRe

 

[Strictly Diesel]

they wont work in parallel, one pump will starve the other pump and burn it up. I tried it quite awhile back and it was worse fuel pressure than a single stock pump. right now im running 2 stock pumps in series and it will hold 35 psi at wot with 275's. Yes i know thats not good, but it works for now.l

Luke...did you feed both pumps with just the stick feed line and a "Y"?

 

[TerminatorEngineering]

Luke...did you feed both pumps with just the stick feed line and a "Y"?

Same question here? Wacker had no trouble running them in parallel, though he did use huge fuel lines. One pump to each head.

 

[Haul_n_horses2]

got a pn for the bigger bosch? I was planning on doing a fass soon, but im open to cheaper options

Kai and a number of others have used this pump on 7.3L PSDs and 5.9L cummers with no problems. Bosch 0 580 254 044 is a 200L/hour at 5 atm (72.5 psi) pump. That compares with about 120L/hour for the stocker. Try getting them at JayRacing.com . If you google it, or check on ebay, you will find fuelexpress.com but the latter has a bad reputation for taking your money and not sending the product. There was a post on that "website that shall not be named"....... oh what the hell, TDS, that warned everybody away from them after having had a 2 month encounter with the Paypal fraud police.

 

[UNLIMITED_DIESEL]

If I am going to have to spend 200.00 on a Bosch 044, then I will spend 300.00 on an aeromotive. I have an abundance of 5/8" parker push loc hose and fittings. I was just curious if it was possible with this setup to maintain a constant fuel pressure. Remember, this truck has stock injectors and we were planning on putting in a set of Hybrids. If we do that, then what is going to happen to the fuel pressure??? I am going to reset the fuel pressure to 60 and see what happens there, but I bet I already know. Are the people that are doing this mod checking their fuel pressure at WOT.
__________________________________________________________________________________________________________

Okay, So I backed the fuel pressure down to 60 PSI, Still have both pumps hooked up, and now I have 20PSI at WOT. WTF?? There is obviously something that I am missing here. I am trying to do this without switching to my fuel pump of choice, but I think I'm waisting Valuable time that I could be using somewhere else. I know for a fact if I put an Aeromotive on it will hold whatever pressure I want it to have, whenever I want it. Is there something wrong with the pumps that I have on the truck or does the stock fuel system really suck that bad? I have had each pump on the truck by itself and in series, I have even switched the pumps locations and that didnt make a difference either. I wouldn't mind using the 044 If I knew for a fact that it would hold fuel pressure, but I have never used it so I'm a little hesitant at this point.

 

[Short Bus]

Luke...did you feed both pumps with just the stick feed line and a "Y"?

1/2 feed split into 2 lines then 1 pump feeding each head.


Edit- can anyone figue out whether or not a 044 pump with a 1/2" pick-up tube will be enough for my 275 cc injectors with 63-64 psi of fuel pressure?