History:
1997 Ford F350, DRW, 4X4, 5 speed, 4:10 rear. I bought the truck from a small dealer. It was in a fleet division. After I bought it, I noticed it was weak when I pulled a trailer.

Modifications:
I cut the exhaust out, put a 3" down pipe and installed a superchips tuner. It was still low on power, and sucking fuel, so I took it to a ford dealer. They replaced 2 injectors and cleaned all of them. It runs better, but still is weak.

Problems:
Poor fuel mileage when pulling. I am lucky to get 10 when towing only 8000 total lbs. It is worse on the stock setting. My accelerator seems weird. Usually, the farther you push the pedal down, the more fuel it will give. Not mine, the first 1" of travel and that is as much as it will give. I can mash it to the floor, but it will not accelerate any quicker. Of course it will go faster in the end, but as far as it getting more power the farther I push it, forget it. Boost seems low. At 2500 RPM 12psi. At 3000 RPM 18psi. I have it set on the highest setting as well. Very little smoke is blown from exhaust, and I am running Cetane booster. My father in laws truck runs as good as mine, and it is bone stock. I should be runnig over 100HP hotter than his. EGT gets no hotter than 1000 degree. It runs the same temp and boost on the stock setting as well.

Question:
Is my boost low on the turbo? Is my accelerator messed up and causing all the problems? Is it low on fuel pressure?

 

Try unplugging the map sensor ...

Test the go pedal

You need to put a voltmeter across the GY/W and the GY/R wires on the connector to the TPS. With the key on, watch the voltage across the range of the throttle to see if there is any flat spots. You should see no less than .37 volts at idle position and no more than 4.5 volts at full throttle. The the third wire, (BRN/W), is the ref. voltage and should be 5 volts all the time.

 

FWIW - this was in the "Superduty" forum also.

Click Here to see the other thread....

 

I saw that ,,,

Just thinking about the two things..... pedal & power .. MPG while towing heavy can be anything (unless its up hill & into the wind both ways )

Friend of mine just went through this with his ...

Not completely resolved yet ...

 

10-4, i think someone suggested that it be posted in this forum.

curious to see what everyone here has to say.

 

Could it be the turbo? For the life of me, I cannot get anyone to tell me what the factory turbo should boost and at what RPM that boost should be. Some have even said the pipes from manifold to turbo could be bad. Does anyone else's accelerator pedal do the same thing as mine? I am not joking when I say the first 1" of travel is my acceleration. I also think my EGT should be hotter than 1000 with the superchip set to top setting. I have been told that it is not uncommon for this year model truck to run 1000 and below with the top setting. But, it heats up just the same on the stock setting. This tells me it isn't getting fuel, but if the turbo is low on boost, it will restrict the fuel since they work together.

 

Lets start with the basics. When was the last time the oil was change, fuel filter, air filter?
Check fuel pressure with a gauge here (left side, second from the top)


Do you have a boost gauge? Where is the thermocouple for the pyro? pre turbo or post turbo?

 

Oil has 1000 mi on it. Air has 2000 mi. I am changing fuel tomorrow, but it has 4000 mi. I do have a boost guage, tied in with MAP line. Pyro is Post turbo like it said in the instructions. I put it about 2" from turbo outlet.

 

Most prefer to put the pyro PRE-turbo, you will get a more accurate reading. IIRC, 1000* post turbo is pushing the limits a bit.

 

you can generally, as a rule, add 300* to the post turbo to get the preturbo temp. i cringe when i hit 900* post turbo with the mods in my signature. i wonder if you're having IDM problem??

 

IDM? Since I don't have an innercooler, I don't think I would be able to reach in to put one in Pre Turbo. I just followed the instructions that came with the pyro, and that is where it told me to put it. Everyone I talked to said that is where they should go. If I am melting my turbo down, that may be why I have low boost, if I in fact do have low boost. Where does everyone elses run?

 

Here is a thread you should read. Who ever you talked to is foolish for telling you 1000 post turbo is ok. Its not.
https://www.ford-trucks.com/forums/7...s-for-tim.html
The best place for the pyro is in the driverside exhuast manifold. EGT's are watched to keep from melting pistons not turbo's.

What is your max boost stock? Best way to test is find a long hill and hammer the throttle all the way up it.

Also while your changing you fuel filter with the filter out there is a small hole in the driverside of the filter housing on the inside. using a q-tip with the cotton take off clean the screen that is in there. It get plugged with junk.

 

Just FYI, I was towing my buddies 26' boat and truck was struggling and burning a bit a fuel. Ended up being IDM related, just throwing that out there for you to keep in the back of your mind... Seems that there are other issues here I'd look at first. Disconnect MAPP and run, see if better. Test pedal like mentioned above, check fuel pressure

-Robb

 

IDM is the injector drive module. it electronically operates the injectors. i wonder if you're getting a weak electrical signal to the injectors and taht might be the reason you arent getting any response past the first inch of throttle pedal. just a random thought.
also check your up-pipes for any leaks. look for soot around the flanges. leaks could equal less boost. check the intake boots at the plenums to make sure you're not leaking out any boost there, also.

btw....dont take this the wrong way, but you're not running 100HP hotter than stock. stock injectors only flow enough fuel for maybe 85 more HP than stock tuning.

 

ah, ROBB! ya beat me to it! lol.

madewell - just reread the original post. its not advisable to tow with superchips top tuning. the egt's get way out of control. youre going to end up melting down a piston. bad situation.