Ok. I've found lots of instruction on how to change to the blue spring upgrade. But no one seems to say why you should do it. So what gives? Why should I spend the time and money to put in the kit? More power? More mpg? Or just couse its a cheep upgrade?

 

Your injectors require a minimum fuel pump PSI to help maintain their health. The original fuel pressure regulator spring maintains too low of a pressure to effectively do that. At $220 +/- each plus labor to change an injector it's a good cost effective upgrade. You should also install a fuel pressure gauge (IMHO) or at least check the before and after fuel pressure to see how the pump is performing.

 

two weeks after I bought my truck (still under Ford's used car warranty) I lost three injectors in short succession on a road trip. At the end of the day dealer stepped up and had my truck shipped back to him from where it was (close to 800 miles), paid for the two injectors I had replaced on the road ($2100) and replaced all 8 injectors, the HFCM and did the blue spring upgrade, on the advice of a senior Ford diesel engine engineer. My fuel pressure was 41 lbs under load. For me, blue spring isn't an upgrade, it's a mandatory change.

Brian

 

There are 3 mods to the OEM fuel system that have been used over the years. The BB mod, Ford blue spring and the GDS spring.

I did this one. For the BB mod you remove the OEM spring and put a BB in the barrel, so to speak, with the spring. This increases fuel spring tension and thus fuel pressure. This made the fuel problem a little better and is the cheapest mod. Some even put two BBs in the barrel and this raised the pressure to somehwere between 75 to 80 psi.

I did not do the Ford blue spring but that seems to be the generic fuel pressure mod today. I believe it raises the normal run pressure from 45 psi to 60 psi.

I did this one. The GDS spring raised the fuel pressure to 105 psi. I called Gillett who sells the spring and asked if OK. They had several people call them since 80 psi was Ford's stated max fuel pressure. They said Navastar told them the 6.0 fuel system was designed for a max fuel pressure of 120 psi. So I ran it for a while. A SIGNIFICANT improvement in throttle response but fuel mileage suffered.

Finally went to an Air Dog II fuel pump with internal regulator. Now I run 70 psi on the road, 75 psi idle and 60 psi when I get on it (not WOT).

FWIW - my fuel mileage went from an average of 15.5 before the mods to 12.5 after the mods. Running the higher then standard OEM fuel pressure (70 vs. 45), modding the fuel line banjo bolts for higher flow, removing the OEM fuel filter and the ADII removing air from the fuel are factors that contribute to the MPG reduction. However, performance is a lot better.

Ed

 

This is very good information, I have the blue spring kit sitting in my glovebox. I ordered it while I was bulletproofing my 6.0 but didn't arrive until 2 days after the work was done. After reading this post I have decided to run over to Ford and have installed today.
Thanks for posting, Michael

 

Just had it installed, first reaction is it runs very smooth at idle. I really can't notice any difference as far as anymore gettyupandgo, but that could be because of all my current mods. Also, injectors are a touch quieter. Just my .02

 

Yea, the blue spring is not really a performance improvement, rather an injector life enhancement.

Did you by chance get a before/after fuel pressure reading?

 

Yes, at idle it went from 52 to 68... Now I'm wondering what that does to fuel economy at idle?

 

I don't think it'll hurt thr mileage plus you don't drive at idle anyway.

 

I unfortunately see a ton of traffic down here this time of year, thank you Canadians.

 

Those are my exact #'s when I did mine. Your 68 may drop a little over time.

Shouldn't make a difference in fuel economy, whatever fuel your injectors don't require for the driving conditions, goes back to the fuel tank.

I think?

 

and Minnesota-ians, New Yorkers, Illinois, Indiana, Maine....

 

With the BLUE spring mod you won't feel the performance increase or see any drop in fuel mileage. It is designed more for reliability than performance.

I did some radical changes to my fuel system and that is the reason I can feel the performance increase and, subsequently, see the drop in fuel mileage. It is all about physics which I'm very familiar with.

If you want to feel performance, put the GDS spring in but a lot on this forum will say don't do it. Been there, done that, had the feeling! My original injectors with 115K on them are still intact.

FWIW - If you really want to help your 6.0, get some Archoil AR9100 friction modifier. I'm no fan of snake oil but AR 9100 is the real deal for 6.0s. I put it in mine this past week and this morning it was 5 degrees F outside. It started like it was 50 degrees. Google it for reviews.

Ed

 

Archoil 9100 works because it is American Eagle oil....a superior species that eats snakes.

 

Wow thanks guys it sounds like it should be a mandatory mod $70 for the kit or $200+ ×8 for the injectors pretty easy choice to me I have to do the head gaskets in a couple of weeks so ill do it then while I'm in there thanks again