Gillette Diesel Fuel Pressure Spring Review
 

Just put in the fuel pressure spring from Gillette Diesel Service. After getting it up to 190*, it seemed to have a little more low end, off line response. :jump: Not bad for a $20 part,

No, I do not have before and after fuel psi numbers because it was easier to install the spring before work than the gauge. Sorry.

Now for the greasy stuff. I pulled the upper Techni-cooler line off of the elbow (you may not have to with the smaller OEM tubing), I also pulled the airbox to allow more movement of said tube. The radiator hose was a pain in the rear. Ended up using a #27 Torx on a ratching 1/4" box end for the lower screw that is nearest the rad hose. Including searching for tools and trying to find a proper course of action, it took about an hour to do it all.

In short, I'm happy with it. I'll let you know what psi I am running after the gauge goes in this weekend.

:c:

What are you using for a gauge? I take it you're still using the stock fuel pump and injectors?

I bought a Glow shift mechanical to electric psi gauge. I know it's not as good as an Auto Meter, but have you priced Auto Meter in cab fuel psi gauges? :bat: OUCH! All I really want is a general idea of where I am.

I was just curious to see what you are using. Some guys go off the gauges on the regulated returns, like the ITP unit. Just trying to figure out where you are reading from. I'm guessing you have it hooked up to the test port on the fuel bowl?

I bought the gauge because it's one of the few things that my Edge won't read. I had to get a metric to NPT adapter to put it into the the filter bowl. It will be on tomorrow afternoon.

UPDATE!!

I put over 200 miles on the Souper Doody over the weekend pulling my 18 foot flat deck trailer. Before the spring swap I got 12~12.5 with the trailer unloaded. I averaged 13.6 this past weekend. :jump: (It's a long story why I wasted 200 miles with an unloaded trailer:dang:).

Procrastinated putting in the gauge. Well, not really, looking for a car, truck club meeting, beer. Didn't leave much time for wrenching. I'll get it in soon, I'm pretty curious what my psi is, too.

:c:

hmmm :humm: Have you gotten your FICM reflashed by anyone that fuel milage kinda seems pore.. I got The Juice With Att Stacked with Diablo sport tuner and Gillette spring and FICM reprogramed by PHP and with J w/A on level 2 and Diablo on 60hp and pulling my 26 foot Donahue tripple axle goosneck trailer Loaded i get 14 mpg at about 75 mph :tu:... 2006 Ford F-250 6.0L:c:

Stacking on a 6.0 = :argh::ouch:

Running either one of those tuners that have NO transmission tuning and towing a trailer will result in a scrap pile of parts for your transmission as well.

the diablosport does tune the tranny and my tranny has never slipped:humm:

How heavy is that triple loaded?

No, it doesn't. It might raise line pressure, but it can not access the TCM like the SCT does.

Either way that is a way heavy load to be hauling with those tunes on.

Well this trailer is just under 8000 lbs light, But I Usually Haul around 15000 lbs but I Have Pulled some Illiagal sh*t and Hauled A Couple loads over 28000 lbs and Idk Ive put 100000 Miles on this truck 85% of the time with my triple axle trailer and the tranny still shifts like the day I bought it. Its a work horse:tu: but FYI I am going to get the SCT tuner cuz I do like GOGO diesel and RCDs tunes for them :yeah:

So you're saying you pull 8-15k at 75 MPH and get 14MPG correct?

Thats Correct Any thing over 15000 Ilbs is a little heavy to be traveling 75mph i usually keep it around 65 then but any thing under that after getting off the scales i hit Interstate 80 and Crank her on up To 75 on flats usually take summits at around 40 deppending on load i try to keep my EGTs under 1300..

4000' elevation + 14.5 wide tires = crappy mileage! The 4000' here kills other 6-Oh owners I know here. Fact is, I pick up a point or 2 when I go to Phoenix (1300').

I get 12.5 in my truck on 38s with stock gears. Thats hand calc and mostly city driving.

The Diablo adds lots of timing which is probably why your fuel mileage is up. But I bet its also streaching your headbolts.

FACT I have Stretched Head bolts.. Im Getting Ready to put the ARP studs with aftermarket gaskets on it with EGR delete kit and Idk My Buddy has an 03 6.0l Whistling P-stroke with SCT and no FICMreflash and no Gillette Spring, but Green aftermarket air Filter stock housing and Banks Turbo Back exhaust on it getting 17.5 no trailer im getting 18.5 to 19 no trailer:tu:

I get 13-15mpg unloaded with my extended cab short bed 4x4 auto. Be happy you get what you get. That is hand calculated for me btw. My buddy has a CC/SB on 37's and stock 3.73's his lie-o-meter says 11mpg. I'm sure it's less. I dont even bother checking anymore. The Diablos run a LOT of timing... that's how they make their power. It's more of a "fooler" than a programmer.

agreed I Like to call it Diablow lol but I am getting SCT tuner Cuz like I sayd My Buddys 03 is averaging around 17mpg:tu:

That's pretty good. Whatever you do... DO NOT get an economy tune. It's a waste of money IMO. You will get better mileage on the higher horsepower programs, IF you can drive responsibly with it (very hard to do). The economy is about the same power as stock, it just uses a little more timing for a touch extra power, but the fuel just isn't there. I found myself flat footing the truck trying to get out of it's own way with that tune and got less mileage than with my X-treme street tune driving like an idiot.

I dont think hed be gettin much worse. You have to remember that the truck is actually driving more miles then the computer thinks due to the bigger tires.

That is true, I keep forgetting that. So a little BETTER than 11... maybe. I still laugh to myself when I hear guys saying they get 22 in their 6.0. Not in this lifetime and if they are, they better hold on to that truck forever.

Someone was tellin me the early 6slows like the 03s were getting over 20 ive never seen it in my truck but ive seen 19 on many good days mostly around 18:tu: couldnt be happier just wish i didnt have so many EGR problems the only reason I dont delete is the extended warranty they dont know I have it tuned and never said anything bout cold air and exhaust?? But They told me EGR Delete would wave bey bey to Warranty:td: :argh: WICH SUCKS I want EGR gone thats about the only problems I have with my 6.0L anymore

It's a tough choice. Having the EGR cooler on there will only accelerate further issues... It seems as long as it's there, it will fail eventually. You would think they would be happy to have it gone, it'd be less work for them.

The 03 trucks did get better mileage when they first came out, but they were thought to kill FICM's and eventually injectors with the strategies they were running, that's why Ford introduced all those new strategies to get reflashed. Mileage dropped severely with most of the newer flashes.

HOLY CRAP! I thought I was the only 6-Oh owner that wasn't afraid to admit that he got azz for milege! :c:

I went from 14~15 to 12~13 in town when I put on those 35s. Although those same 35s have put me up to 18.5 at 70 (corrected), unloaded on the highway.

I'm no math wizard, but I did figure out how to hand calculate my mileage for my tire size with some help from an off road web site and an Embry-Riddle math instructor.:rocking:

Anything over 17 I honestly find hard to believe. Especially with the newer flashes from Ford. 35's shouldn't be a huge difference since some of the trucks came with tires almost that large from the factory. I believe some of the tire options on the 20" wheels came out to something like 34.2" We avgd 14.5 in my buddies crewcab going from NY to NC with a 6" lift and 35's (He had new 37's waiting in the garage and didn't want to do the long trip on the new rubber). Not too shabby. The faster we went and the harder the truck got drove, the better the mileage became for some reason though...:humm:

I seem to get around 15 no matter what, driving slow, driving hard and fast, towing... doesn't seem to matter. I've run synthetics, non synthetics, additives (hoping the rev-x will work now!) and still it's 15.

When I first got my programmer I did a comparison that you guys will find humorous. I loaded up my economy tune from Eric @ Innovative and filled the tank (I fill up to the top of the filler neck for the most accurate mileage testing). I drove the truck for the entire tankful UNDER 2000 rpms and UNDER 10psi (according to the factory boost gauge). That was the hardest thing I've ever had to do lol. I avg'd a whopping 15.1mpg. I then loaded my x-treme street up also from Eric @ Innovative, then filled the tank again, I drove this entire tank like a maniac. Mind you both fill ups did have a fair amount of highway driving, and both I did 70mph for cruise, however my in-town driving and accelerating habits were drastically different between the two. I checked my mileage at the end of that tank and netted 15.3mpg. Guess what happened then? I removed my economy tune from my SCT and never used it once again. I asked Eric about this after and he said that sounded right, and that the economy tune is better for putting in the truck if you have to let a buddy drive it.

Xtreme tunes all the way!:c:

:argh: Over torqued the adapter to the fuel bowl! :argh: Time to figure out how that comes off.....

Same here. I usually avg mid 15s no matter what. I just switched mine to amsoil from reg rotella and had the guy where I bought it telling me about how they always pick up a few mpgs when they switch. I already didn't believe him since I didn't notice a difference in the cummins when I switched it to synthetic. Neither truck has gained any mpg from synthetic. I recently tried the Ford fuel additive in the 6.0 and the first tank was in the 17s but after two more tanks I'm right back in the mid 15s while still using it. I'm happy with the mid 15s because its better than any gas truck I have had but I will always try to get more out of it. I just never expect to. I am going to order one of these springs and try it out. Its cheap enough I won't be disappointed if nothing happens.

Since this was such a pain for me to find, here's the p/n for the secondary fuel filter/oil filter housing: 3C3Z-9C166-AA. Your freindly neighborhood Ford Service Rep should be able to find the recommended gaskets as well.

In stead of tearing into the part, I tried looking up the instructions (the IPB wasn't all that great):argh:. Let's just say swapping the internal parts over is so easy, a caveman could do it!

I'll have it AND the gauge in tomorrow after work.

had to look at where y'all are from with your fuel mileage, Im from TX mostly flat and rolling hills, I do get about 22-25 MPG running empty, The 35ft gooseneck when loaded with hay will bring it down to around 18 if I keep it around 65 MPH. When I pull the camper, all fuel mileage bets are off. Its like dragging a parachute behind me.
Still have to laugh at the guys who swear ANYTHING but SCT will blow your transmission and kill the engine. Kinda reminds me of an old Beatles song "He cant be a man, cause he dont smoke the same cigarettes as me,"

How much pressure did the gauge show? :pca1:

25mpg out of a 6.0? You better never sell that truck cause you've got the only one that will do that!

Damn sending unit is bad, got put on day shift at work and I haven't been able to call GlowShift before they close (lovely PST). :argh: I'll get to it soon, too much headache went into installing that thing!

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1. Not to give Mdub707 a big head, but don't sell a rig that turns those kinds of numbers.
2. The song in question is "Satisfaction" by The Rolling Stones.

One year and 10 months later I finally get around to getting things squared away. Here's the numbers everyone was wanting with the Gillette spring:
Idle: about 95 psi
WFO on SRL tune: about 60psi

Conclusions:
1. The GlowShift gauge probably worked all along, that spring was pegging it out. Had I known that the spring was such a high psi piece, I probably would have left that gauge in.
2. Dropping 30~35 psi with my foot in Matt's SRL tune makes me glad that I don't have a blue spring.
3. It's been almost two years, and I don't baby my truck, if all of the horror stories of shreading o-rings and stuff were true, I would have done it already.

Well as long as the blue spring holds more than 60psi, you shouldn't be going below that no matter what spring is in there... it's a volume thing. You're not always going to drop 30psi no matter what. If it holds WOT at 60psi, it should do it with either spring in there bud. You're just over-stressing the pump at idle by trying to make 80+psi with it...

Because it's a return pump, I don't know how much stress it is really putting on it. I was talking to one of my power plants guys and this came up (helos and diesels have very similar fuel systems). Now if it were a dead head, like the Holley Blue in my Hot Rod, the extra psi would probably blow it up.

Bottomline, I have a blue spring on the way, if it keeps it above 60psi WFO, I'll leave it in. I'll keep y'all posted when I make the change. I won't take two years this time. :w2:

haha, interested to see how you make out with the blue spring. In theory... it shouldn't drop more than the lowest reading you had on the gillette spring... We know that spring will hold 95psi right? Meaning it wont pop off and bleed pressure less than that. This tells us the lower pressure at WOT is just from the injectors draining pressure, the spring is no longer even in the equation at this point. So as long as whatever spring is in there can hold higher than 60psi, it should never fall lower than where you were with the gillette unit. Make sense? It does in my head, but sometimes translating that to words is harder.

And of course we all know, theory doesn't always = real life.

:pca1:

Blue spring in, holds about 65~70 psi, doing a short run to Speedco for coolant/information, we'll see what the WOT psi is. Sinister coolant by-pass also in. :jump:

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Kinda like the blue spring, kinda don't. I like that it doesn't fluxuate as much pressure, but I don't like seeing 55 psi with my foot in it. I read that the Gillette spring can be "tuned", as in trim a coil, drop 10 psi at idle. By that math, 2.5 would be 25 psi taking it down to 70ish cruise psi.

You'll get to a point clipping coils where the spring is no longer even in contact. Translating a PSI drop by clipping X amount of coils is a very general rule of thumb, if you do want to clip it, be careful, start small and work up.

Why is dropping to 55psi a bad thing? That's right where Ford wanted it anyways...

Which fuel filters do you use? New style with the lip and the o-ring on the frame mounted one, or the old one's?

There is no need for 70+PSI of fuel pressure IMO. 55-60 is ideal. Have you given any though to reading behind the heads at all? :humm: