I have a 2003 F150 5.4L SCrew and I'm trying to install the 1715 Superchips Microtuner 87octane program. Help!

The first step of the 1715 installation is to disable the Fuel System. The manual explains that there might be a special process to disable the fuel system. I examined the photos of the possible Fuel System in 2003 and Later Ford Exp and Navs but mine does not look like the one pictured in the Microtuner manual. I assume that this means that mine is the old fuse type, described in step 1. I opened the auxilary fuse box and checked the owners manual and there are two fuses; location 10 has a 20A fuse labeled Fuel Pump, location 18 has a 15A fuse labeled PCM, Fuel Injectors, Fuel Pump Relay and Mass air flow sensor. Which one of these is the right one? I don't see any other fuses for the fuel system.

I have a picture of my trucks passenger side firewall that I tried to include in this post to verify that I do not have the new PCM type but I'm unable to figure out how to include the image.

Any help anyone could provide would be greatly appreciated.

 

Pull the fuel pump fuse, location #10.

 

there may be two fuses to pull. Mike did a really in-depth response to something like this not too long ago. If you haven't tried the search feature on this yet, you might check it out.

 

Thanks! I did some searching and found a couple of posts from the past discussing the same issue. I ended up pulling the 20A fuse from location #10 Fuel Pump. Performed the installation with no problems. Truck started right up. Can't wait to drive it in the morning.

Thanks again for the help!

 

You will keep us posted on the results, right?

 

The location varies, but it IS a 20 amp fuse. On the Lightning, it's #10; on the 97 F150, it's #17.

 

Driving it today. Everything seems to be working fine.

I can tell there is some addtional power and that the shift points are different. I adjusted for my new BFG 315/70/17s and accepted the Superchips defaults for all of the rest. No noticable loss of power over the 265s. I'll need to drive it some more to let it work through it's adjustment period but so far so good.

The next question will be my mileage. I'm hoping the 1715 will compensate mileage wise for at least some of the change in tire size. I was averaging about 14 before the tire change and I'm hoping to at least stay in that ballpark.

 

Actually the next question is how long you can wait before you switch to the performance program. At least that was my next question and the answer was "not very long"..........

 

Hi MSU,

Glad you're up & running with the 1715!

I wanted to point out something here, for anyone contemplating the use of 34 or 35 inch tires......................

Basically, it's just that they need to be realistic in their expectations of what the 1715 can do - for example, do not think that the 1715 is going to somehow "compensate" for the loss in fuel mileage due to the large decrease in torque multiplication caused by installing huge 34" & 35" tires - that generally isn't going to happen.

Remember, using 34-35 inch tires on the stock gearing forces the engine to work below it's power band much of the time - this also adds a lot of additional rotating mass & sheer weight with those much bigger tires as well, further hurting mpg and compromising the braking system, too.

Sure, the truck "feels" better with the additional power of the 1715 - and we're very happy that's working for you, to be sure! But please do not expect a "significant" fuel mileage gain in your particular situation, as that probably isn't going to happen with those 35's.

When installing anything taller than maybe 33.0" tires at the very most, plan on also doing a gear ratio change to compensate, so that the engine can turn **at least** as many rpms for a given speed & gear that it was from the factory. Not doing the required gear ratio change hurts performance, driveability, throttle response and especially fuel mileage.

While the Micro Tuner will help the truck to feel better from the additional power, it's generally not going to "compensate" for a set of 35's by getting the truck back to whatever mpg it was getting on the stock factory tires.

The fact that most people who actually calculate their fuel mileage correctly *do* see an improvement in fuel mileage from the Micro Tuner has little to do with your situation, MSU. You've probably seen a lot of people here talking about the increased mpg they got from the Micro Tuner, and perhaps thought that would happen for you, too - well, you might see some small mpg improvement, but generally speaking, it most likely won't help much in that regard with 34's, 35's, etc. - that's just to much tire to run on the stock gearing & hope for any significant fuel mileage gain from the 1715.

In reality, when a vehicle owner goes up to 34-35 inch tires, they also need to do a gear ratio change *and* a brake system upgrade on at least the front brakes to compensate for the large increase in rotating mass. Otherwise, the engine is working below it's power band much of the time, and the braking system cannot stop the vehicle nearly as well as it did before, and will overheat & boil the brake fluid *much* quicker than with the stock tires sizes.

This is mostly just general FYI stuff for anyone contemplating the use of taller than 33.0" tires - and I just wanted to let you know not to expect the 1715 to get you back to the same mpg you got before the big tires, as that most likely will not happen. It would be nice if it did, and most people *do* see some mpg gain from the 1715 - but in your case, the chances of it getting you back to the same mpg as before the tires are slim, I'd say - not with 34's or 35's.

Best of luck with the 1715 & your truck, I hope this all works out well for you!

 

Mike,

Thanks for all of the useful information. I very pleased with the results of the 1715 so far. I have noticed that everything you said about what to expect performance wise is right on the money.

My brakes do seem to be less effective with the larger tires especially when towing my boat. I am interested in doing the brake system upgrade that you mentioned. Can you elaborate a little for me on this? What needs to be upgraded; pads, calipers, rotors? Is doing just the front brakes enough? Do you have any recommendations?

As for the regearing, I'll probably wait and see how the truck performs before going down this road. I probably would have gone with 285s except for the great price I got on the 315s. SO, I'm not sure about spending the money to go swapping out gears. However, the brakes are another story. You can overlook the equipment that makes you go but you and better not overlook the equipment that makes you stop.

Thanks again for all of the useful information.