Hi Bart here from the Netherlands!

Autotech sweden mapped my car for the td04hl-18t and runs like a dream! But i havent yet fitted a fuel return line.. so it runs lean up top.
But i cant really find any info on how to do it.. my idea was to tap a hole in the end of the rail. And use that as a feed.. but what do i do with the old feed? Use that as return? And how does that affect the stock fuel pressure regelator? Kind regards.

translated from google ( dont mind the mistakes )

Hej Bart här från Nederländerna!

Autotech sverige kartade min bil för td04hl-18t och kör som en dröm! Men jag har ännu inte monterat en bränslereturledning ... så den går lutad uppåt.
Men jag kan inte hitta någon information om hur man gör .. min idé var att knacka på ett hål i slutet av skenan. Och använd det som ett foder .. men vad gör jag med det gamla fodret? Använd det som retur? Och hur påverkar det lagerbränsletrycksregulatorn? Vänliga Hälsningar.

I’ve never done any proper tuning on a T4, but why would you need secondary return line?

If you’re leaning out at higher rpm’s you might be better off with a progressive fuel pressure reg, or larger injectors.
Mind that would probably compromise the fuel map.

You could pm torpis, he knows a thing or two about these cars.

BartJongedijk skrev:

Hi Bart here from the Netherlands!

Autotech sweden mapped my car for the td04hl-18t and runs like a dream! But i havent yet fitted a fuel return line.. so it runs lean up top.
But i cant really find any info on how to do it.. my idea was to tap a hole in the end of the rail. And use that as a feed.. but what do i do with the old feed? Use that as return? And how does that affect the stock fuel pressure regelator? Kind regards.

translated from google ( dont mind the mistakes )

Hej Bart här från Nederländerna!

Autotech sverige kartade min bil för td04hl-18t och kör som en dröm! Men jag har ännu inte monterat en bränslereturledning ... så den går lutad uppåt.
Men jag kan inte hitta någon information om hur man gör .. min idé var att knacka på ett hål i slutet av skenan. Och använd det som ett foder .. men vad gör jag med det gamla fodret? Använd det som retur? Och hur påverkar det lagerbränsletrycksregulatorn? Vänliga Hälsningar.

Hello,

If the car are re-mapped by Autotech there are not chance in hell its running lean on top. Probably are you exceeing the boost limit (usually well under 1.5bar) or something is broken.

Which year is the car?

Stock they have a setup without any boost correction so pressure over the injectors drop on boost. This makes it hard to fiddle with the fuel system without making a complete new mapping. We usually add another feedline using a banjo connector drilled under a 98-00 fuel rail. Stock supply as return, positions switched at the tank armature. There are blanks suitable for return via the old feedline so to speak.

Its running lean because Autotech told me to add a return line. Lean I mean 12.9 in second gear. Rest seems ok. But can I maintain the fuel pressure regulator on the rail? I’m going to tap a fitting in the rail for the feed. And switch the lines on the tank. Plus removing the T that’s at the fuel filter.

The map is for stock phase 2 of green giant injectors.

The car is a 2001 t4 with shimmed liners. Running 1.4 bar of boost.