So im looking for some insight here, been battling with this issue with my truck for quite some time now...any help will be greatly appreciated
My truck: 2001 f350 srw 4x4 cc lb auto,130xxx miles, 4in straight pipe, aem intake, ts 6 pos with swamps tunes, 275/60r20 tires, bellowed up pipes,borg warner lowered vain turbo compressor wheel from guzzles, guages...
I have owned this truck for about 5years and from day one it averaged 15 mpg city/ 20 hwy. My milage dropped off to around 11mpg some time ago (going on 2yrs) and seems to lack the power it once had.
Things I have done or checked include, cleaned ebp tube and sensor, installed bellowed up pipes, replaced intercooler boots, pressure tested intercooler, ( can boost upwards of 27psi) checked fuel pressure (around 60 psi) checked hpop pressure/ duty cycle(30% at 2600 psi or so) new cps, truck has no rolling resistance, all datastream vitals on my scanner are good, replaced fuel filter, checked icp reading on scanner and compared to a mechanical guage, have done the buzz and contribution tests on my injectors countless times and they pass...im sure there is more I have done as well.
I have no contaminated fluids, no smoke etc just low mpg and lack of power.
If anyone has any ideas here please let me know! Injectors? Thanks in advance

 

do u still have stock converter in it?

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I have a 2001 as well. And ive been told that year the converters suck... Im about to put a billet converter in mine. They need to lock up to make it pull and get better MPG. Thats just what ive been told.

 

Yea stock converter, trans is all stock original. That is one of the 2 things im leaning towards. Trans issue or injectors...trans seems to shift fine converter locks up when it should but lately sometimes it skips t/c lock in 3rd and shifts right to o/d. Are you having somewhat the same symptoms with your truck? Which converter are you going with for your truck?

 

yeah my tranny dose the same thing. I put the TS 6 pos chip in it and it ran great, but now im losing power when i get on the gas and its making a bad Howling noise. Im taking the chip out today and run it to see if noise gose away. Mechanic i took it to said those converter suck and needs a new billet one, but 2,600$ for a rebulid and new converter i dont like that idea. ugh..

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I had a F 250 2000 7.3 for a long time and I had never had a tranny problem with it 325k miles on it. But my 2001 RF350 has 225k and runs like a dang Toyota..

 

Ya I hear ya, im looking at either a pricey trans build or injectors I guess...iknow with my luck which ever I do wont fix the problem so I will end up just adding new parts until the problem is solved like I have been doing. I do have a spare trans out of an 02...know if those converters are any better?

 

I'm not sure on the 02' ill check around and see. Prob just going to take mine to the mechanic place today and see what they think that dang noise is on my truck.

 

How much psi is your turbo building?

 

The factory TC locks just fine. There is nothing wrong with the TC in a 2001... There is an issue with the mechanical diode on the 2001 my trans, but it has nothing to do with how the trans functions until it just up and dies.

TC is not your issue.

You say you have pressure tested the IC, have you tested the entire system?

I would suspect a boost leak, but with the boost levels your hitting that might not be the case.

130k I doubt its an injector issue, but it could be bad or getting bad injector O rings.

When you checked the fuel pressure was it under load? How did you test it?

 

Check the hose clamps off the turbo. Mine was lose so I tighten it and it made a world of diff..

 

The ic boot clamps are all good and tight...when I pressure tested the cooler I tested from the cac tubes off of the spider and had no leak down. Couldnt fig out a way to test the rest so I replaced the boots. I dont believe it is a boost issue anymore...turbo spools fairly quick. Wouldnt injector o-rings cause contaminated fuel/oil or some smoke? I tested the fuel psi with a mechanical guage off of the filter housing port. I checked it idle than drove it and watched the guage and the needle never moved. I wouldnt say that there was an excessive load but normal driving load. Think I will check fuel psi again

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I can build over 25 psi if I really lug it in high gear...