Notices
Fueling & Injection Fuel Pumps | Injectors | Rails | Regulators | Tanks

Out of pump, injector, or both.

 
Old 09-11-2018, 01:48 PM
  #1  
10 Second Club
Thread Starter
iTrader: (2)
 
BCNUL8R's Avatar
 
Join Date: Jun 2005
Location: Oskaloosa, Iowa
Posts: 581
Default Out of pump, injector, or both.

Setup is cam only sbe ls1 procharger and 10 pounds. Fuel is E70. Pump is external Magnafuel 4301. Injectors are deatschwerks 95 lb/hr but actually flow 89 lb/hr at the 43.5 base pressure I知 running. I知 at 95 percent duty cycle at 6600 rpm. I still have the evap system plus a -8 tip over vent in the tank. Magnafuel didn稚 like the hard 90 I have before the pump and recommended a hose bend 90 so I値l do that. I want to run a couple more pounds so curious if I should go to a 4303 pump or if I need injectors also.


Last edited by BCNUL8R; 09-11-2018 at 01:59 PM.
BCNUL8R is offline  
Old 09-11-2018, 02:18 PM
  #2  
Staging Lane
 
AUS Injection's Avatar
 
Join Date: Aug 2018
Posts: 90
Default

If you are at 95% duty cycle already, I would highly recommend upgrading your injectors if you want to run a couple more pounds. Shoot me an email if you have any questions! [email protected]
AUS Injection is offline  
Old 09-11-2018, 03:08 PM
  #3  
10 Second Club
Thread Starter
iTrader: (2)
 
BCNUL8R's Avatar
 
Join Date: Jun 2005
Location: Oskaloosa, Iowa
Posts: 581
Default

Originally Posted by AUS Injection View Post
If you are at 95% duty cycle already, I would highly recommend upgrading your injectors if you want to run a couple more pounds. Shoot me an email if you have any questions! [email protected]
Should I really be at 95 percent duty cycle with 89 lb/hr injectors on E70 fuel at an estimated 550 to 600 rwhp?
BCNUL8R is offline  
Old 09-11-2018, 04:42 PM
  #4  
Staging Lane
 
AUS Injection's Avatar
 
Join Date: Aug 2018
Posts: 90
Default

Originally Posted by BCNUL8R View Post


Should I really be at 95 percent duty cycle with 89 lb/hr injectors on E70 fuel at an estimated 550 to 600 rwhp?
At that horsepower, your injectors should be just fine, and shouldn't be at 95%
AUS Injection is offline  
Old 09-11-2018, 05:11 PM
  #5  
10 Second Club
Thread Starter
iTrader: (2)
 
BCNUL8R's Avatar
 
Join Date: Jun 2005
Location: Oskaloosa, Iowa
Posts: 581
Default

Originally Posted by AUS Injection View Post
At that horsepower, your injectors should be just fine, and shouldn't be at 95%
That's kind of what I suspected, but thought I'd ask to make sure. It's got to be the pump maxed out or a restriction. I've got -10 from tank to pre filter with that hard 90 into filter. Then -8 out post filter all the way to rails in series. My crossover is only -6 though because I used the supplied oring fittings. The regulator is Magnafuel 9950-B and using the stock feed as a return.

So I will plan on improving a couple restrictions and have the Magnafuel 4301 rebuilt to a 4303.
BCNUL8R is offline  
Old 09-11-2018, 05:38 PM
  #6  
Staging Lane
 
AUS Injection's Avatar
 
Join Date: Aug 2018
Posts: 90
Default

Originally Posted by BCNUL8R View Post
That's kind of what I suspected, but thought I'd ask to make sure. It's got to be the pump maxed out or a restriction. I've got -10 from tank to pre filter with that hard 90 into filter. Then -8 out post filter all the way to rails in series. My crossover is only -6 though because I used the supplied oring fittings. The regulator is Magnafuel 9950-B and using the stock feed as a return.

So I will plan on improving a couple restrictions and have the Magnafuel 4301 rebuilt to a 4303.
Yes sir its gotta be your pump
AUS Injection is offline  
Old 09-11-2018, 07:54 PM
  #7  
Restricted User
 
Join Date: Mar 2014
Location: Ohio
Posts: 6,703
Default

Increase your base fuel pressure and see if duty cycle goes down. If it does, its your injectors. If it doesn't, its your fuel pump.
JoeNova is offline  
Old 09-11-2018, 08:08 PM
  #8  
10 Second Club
Thread Starter
iTrader: (2)
 
BCNUL8R's Avatar
 
Join Date: Jun 2005
Location: Oskaloosa, Iowa
Posts: 581
Default

Originally Posted by JoeNova View Post
Increase your base fuel pressure and see if duty cycle goes down. If it does, its your injectors. If it doesn't, its your fuel pump.
Nice trouble shooting tip thank you.
BCNUL8R is offline  
Old 09-14-2018, 03:28 PM
  #9  
9 Second Club
 
Join Date: Nov 2003
Location: Norn Iron
Posts: 12,312
Default

or just monitor fuel pressure....if it's dropping, it needs fixed.
stevieturbo is offline  
Old 09-24-2018, 02:33 PM
  #10  
TECH Enthusiast
iTrader: (3)
 
Join Date: Oct 2007
Posts: 629
Default

dido, get your pressure at the rail onto your logs. you might be supprised that you are dropping pressure.

is your injectors a flat base with a boost ref fuel pressure regulator? you need to log fuel pressure to ensure that your fuel pressure rises 1:1 with boost
Chicago TDP is offline  
Old 09-29-2018, 09:27 AM
  #11  
TECH Fanatic
 
Join Date: Jun 2003
Posts: 1,453
Default

Originally Posted by AUS Injection View Post
Yes sir its gotta be your pump
The 4301 supports up to 1500 hp and the 4303 supports up to 1700 hp. Read that 4301 is not continous duty but the 4303 is continuous duty. It only requires 12 amps, but couldn't find voltage requirements. The injectors support more than 600 hp.

So when you say "it's gotta be the pump", do you mean it is failing (not a continuous duty pump) and can't maintain maximum pressure and volume anymore?

Is the pump getting 13.5 volts at the pump at 6600 rpm, or perhaps a drop-off of voltage or amps to the pump at 6600? A lot of stock alternators drop off at 6200 rpm (or 18,500 rpm at the alternator) dependent on pulley combination (crank pulley and alt pulley). At what rpm does duty cycle raise to 95?
dlandsvZ28 is offline  
Old 10-12-2018, 06:48 PM
  #12  
10 Second Club
Thread Starter
iTrader: (2)
 
BCNUL8R's Avatar
 
Join Date: Jun 2005
Location: Oskaloosa, Iowa
Posts: 581
Default

Originally Posted by dlandsvZ28 View Post
The 4301 supports up to 1500 hp and the 4303 supports up to 1700 hp. Read that 4301 is not continous duty but the 4303 is continuous duty. It only requires 12 amps, but couldn't find voltage requirements. The injectors support more than 600 hp.

So when you say "it's gotta be the pump", do you mean it is failing (not a continuous duty pump) and can't maintain maximum pressure and volume anymore?

Is the pump getting 13.5 volts at the pump at 6600 rpm, or perhaps a drop-off of voltage or amps to the pump at 6600? A lot of stock alternators drop off at 6200 rpm (or 18,500 rpm at the alternator) dependent on pulley combination (crank pulley and alt pulley). At what rpm does duty cycle raise to 95?
The 4301 is a continuous duty pump and supports 1500 hp on pump gas naturally aspirated at carb pressures. No way it's going to support 1500 on E85 at EFI pressure in a boosted application. I never go below 13.7 volts and the injectors hit 95% duty right at the shift point 6550 rpm. I had the pump rebuilt to 4303 specs and is back on its way to me. For reference the 4301 is done around 600 rwhp through an auto trans on E85. The 4303 should cover me to my goals.

BCNUL8R is offline  
Old 10-15-2018, 09:41 AM
  #13  
Staging Lane
 
AUS Injection's Avatar
 
Join Date: Aug 2018
Posts: 90
Default

Let us know how it works out when you get it going!
AUS Injection is offline  
Old 10-16-2018, 03:51 AM
  #14  
10 Second Club
Thread Starter
iTrader: (2)
 
BCNUL8R's Avatar
 
Join Date: Jun 2005
Location: Oskaloosa, Iowa
Posts: 581
Default

Originally Posted by AUS Injection View Post
Let us know how it works out when you get it going!
It's together running now, but all the tracks are closed for the winter. I don't think it will leave the garage again until next spring.
BCNUL8R is offline  
Old 10-16-2018, 10:39 AM
  #15  
Staging Lane
 
AUS Injection's Avatar
 
Join Date: Aug 2018
Posts: 90
Default

dang it
AUS Injection is offline  
Old 11-22-2018, 05:45 PM
  #16  
TECH Senior Member
iTrader: (3)
 
Old Geezer's Avatar
 
Join Date: Jun 2004
Location: GA, USA
Posts: 5,385
Default

What's the micron rating on the pre pump filter?
What's the voltage AT the pump?
Have you done volt drop testing on both sides of the pump?
Old Geezer is offline  
Old 03-25-2019, 07:33 AM
  #17  
10 Second Club
Thread Starter
iTrader: (2)
 
BCNUL8R's Avatar
 
Join Date: Jun 2005
Location: Oskaloosa, Iowa
Posts: 581
Default

Update for those that offered tips and were curious how it worked out...

It was a long hard winter so I wasn’t able to do much testing until now. So I went ahead and had my 4301 pump rebuilt to a 4303. I replaced my -6 fuel rail cross over with -8 so everything from the pump to regulator is -8 minimum. Still using -10 from tank to pump, but replaced the hard 90 before the pre-filter with a hose bend that seems way less restrictive. Went ahead and put a smaller pulley on the blower as well. I left base pressure at 43.5 to start with, but seeing 14 psi at 6800 rpm I was hitting 100 percent duty cycle. I raised fuel pressure base to 50 and adjusted the tune accordingly. That dropped duty cycle dramatically and I’m still a little rich in boost while still having the ability to raise fuel pressure to the normal 58 if I choose to.

Thank you for all the input.
BCNUL8R is offline  
Old 03-25-2019, 10:29 AM
  #18  
TECH Senior Member
 
Join Date: Jun 2016
Location: Central Cal.
Posts: 10,200
Default

Looks like you attended to those details that matter, and you are still getting fuel at pressures somewhat below normal! Great job!
G Atsma is offline  
Old 03-25-2019, 12:17 PM
  #19  
Staging Lane
 
AUS Injection's Avatar
 
Join Date: Aug 2018
Posts: 90
Default

Great News!
AUS Injection is offline  
Old 04-05-2019, 05:22 AM
  #20  
10 Second Club
Thread Starter
iTrader: (2)
 
BCNUL8R's Avatar
 
Join Date: Jun 2005
Location: Oskaloosa, Iowa
Posts: 581
Default

Ok I spoke to soon. Trying to add more boost, but already hitting 100 percent duty cycle. I知 at an estimated 650 rwhp with E70. Magnafuel said check filters. They look good, but I went ahead and ordered new ones just to rule that out. Here is a video I made of the fuel flow from the rails while jumping the relay to run pump. Pump tested 13.5 volts at the pump. I also gave it a few revs with my fianc watching to verify the regulars jumping up fuel pressure when it hits boost which it did. 55 psi base, about 48 at idle and jumped up to about 58 psi with a rev. I don稚 currently have a way to log fuel pressure in hptuners, but voltage never goes below 13.7 in the log. Injectors are 95 lb/hr at 43.5 psi my set tested at 940 ish cc/min so not drastically lower that advertised and well matched.

BCNUL8R is offline  

Thread Tools
Search this Thread

About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: