Fuel Lines- Need Help

Treachery

Founding Member
Jun 9, 2002
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See mods in my signature.

I had a my 93 Mustang GT dynotuned and the tune could not be completed. The 60lb fuel injectors were maxed out and there was still not enough fuel. The 255lph fuel pump was working fine.

The tuner and other sources recommended larger fuel rails and larger fuel lines be intalled to fix the lack of fuel problem. My fuel rails and fuel lines are stock.

Regretably, i don't know much about fuel lines & rails.

I know where to get the fuel rails but i'm having a hard time locating larger fuel lines. The stock fuel lines are 5/16" and an upgrade would be 1/4". Please correct me if i'm mistaken.

Is this the fuel lines i'm looking for?

http://www.mustangsunlimited.com/it...=Air/Fuel&subCategory=Fuel+Lines&CatKey=74-01

And what's this?

http://www.brothersperformance.com/...gt-stainless-steel-fuel-line-kit-2-piece.aspx

Thanks!
 
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1/4 is smaller than 5/16..... if you want bigger go with 3/8 or 1/2 or 7/16. your issue is not fuel pressure but volume. you will only flow as well as your smallest part. Go down to Advanced and get all sizes of fuel hose you can just run your own fuel lines in whatever size you want up to the rails. Just make sure the pressure from the pump cant blow the line off.. ( ask me how i know)
 
You will need to run some new fuel feed lines or braided hose. The 3/8" & 1/2" aluminum tubing works well, but you will need a flaring tool and bending springs to fabricate the lines. Braided hose is easy to run and route, but is much more expensive. It is about $3.50-$4.00 a foot plus the end fittings, which are $3-$4 each. Fabricating hose assembles can be difficult, but anyplace that makes hydraulic hoses can do it for you for an extra charge. See http://www.amazonhose.com for more information.

For some help fabricating your own stainless steel hose assemblies, see
http://www.turbinefun.com/Stainless_Braided_Hose_Assembly.asp

For stainless steel braided hose and fittings for automotive use:
See http://www.summitracing.com/search/?keyword=stainless steel hose&dds=1
http://www.summitracing.com/search/?keyword=stainless steel hose&dds=1

http://www.jegs.com/webapp/wcs/stor...hall&searchTerm=stainless+steel+hose&x=18&y=4

See 13. See [url] http://www.eaton.com/...rformanceProducts/FittingsProducts/index.htm for more information on High performance automotive hose productsl for more information on High performance automotive hose products

AN fittings require a 37 degree flaring tool. A standard automotive or household plumbing tool is 45 degrees and cannot be used with AN flare fittings. If you do, the flare is subjected to too much stress when the fitting is tightened, and is likely to fail or leak.

See http://www.mscdirect.com/ , http://www.mcmaster.com/ or for the flaring tool you will need . Prices start at $85 and go up

http://www1.mscdirect.com/CGI/N2DRVSH?PACACHE=000000013509163
View attachment 148619

http://www.mcmaster.com/#flaring-tools/=b4fxc3
2721ap1l.gif


Last time I was in Summit racing, they had a 37 degree flaring tool for less than $40. It may or may not be a catalog item.
 
I had to put this project of the shelf due to my daughter being born but now i'm back at it... ;)

I've upgraded my fuel lines and rails & fuel pump to Aeromotive 340 (signature updated). All this had NO effect. Fuel still cuts out at around 420hp, 4000rpm, 100mph. Fuel injectors at 100%.

I have attached the best 2 dyno runs and as you can see, the graph falls at around 420hp at 100mph. The third the chart containing the volts, AFR & PSI was obtained from a 3rd tuner who was getting the same result.

According to the tuner's notes, adjustments to the fuel curve had no effect. Reason unknown. Vehicle runs out of fuel under boost. Fuel injectors are maxed out and there is still not enough fuel. The recommendation was to install larger fuel lines and rails which I did. The result was no effect.

I had first thought that the 9AL had something to do with the problem. But wouldn't the tuner see that this was the problem since he is connected directly to the computer?

This problem has got me baffled and I am out of ideas. Needless to say that I can no longer pump tons cash into this 20 year project. I need answers.

Judging by the graphs & the info given, can you help?
 

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Ur out of fuel? Or ur tune is not right? What psi at high rpm? Has your tuner done a true flow test? We only run 39 lb inj off a wlb 255 and an msd BAP on the 2004 mac. With dyno tested 455 hp na and 700 hp with NOS. We have never ran out of fuel. On that note we are now having issues with the psi dropping but sup the wlb 255 is going out. I have herd that with the forced induction a BAP is a must cause as manafold pressure increases the amount of vac going to the reg that controls the fuel pump decreases and slows down the pump. We had this issue with ours even with it being NA. The Bap fixed the issue. Also what is the duty cycle of your pumps set at?
 
Your graphs are mostly unreadable.

To maintain rated fuel flow for injectors, you have to increase the fuel pressure 1 PSI of each PSI of boost.

Example: Injectors are rated at 60lb, at base fuel pressure of 40 PSI. You have 10 PSI boost. The effective fuel pressure is then 30 PSI. In order to get the same 60 lb fuel flow volume, you need to crank the fuel pressure up 10 PSI to 50 PSI.

See http://users.erols.com/srweiss/#jcalc for some calcultors to help you figure ou the injector size and flow rating.

http://users.erols.com/srweiss/calcpchg.htm