2001 7.3 poor mpg, lack of power
 

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?

---AutoMerged DoublePost---

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..

---AutoMerged DoublePost---

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.. lol

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

---AutoMerged DoublePost---

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

Anyone have any other ideas/insight? Im hoping that this issue is caused by something I have overlooked but could I be that lucky? ya, I Doubt it...

maybe you have leaky uppipes, u need like an inspection mirror and a flashlight i didnt think mine were leaky cus i found no soot but i went to do my manifold gasket and when i took manifold down whole uppipe came with it:argh:

Well that was what I thought so I started there. Up pipes leaked so I installed new bellowed up pipes and no more leaks, but still bad mpg and lack of power

I am not a diesel mech but I am starting to learn more since it is time for me to work on my 2000 I had since new. I saw the same thing in my truck when I did not put my additive in. I use diesel kleen cetane boost, the new diesel we get sucks and runs like shit if you do not boost it up. just what I have found out. I have a 6 sp in my truck.

I too use to run diesel kleen pretty much every tank. I stopped for a while then when I started losing mpg I went back to running it and only saw maybe a .5 mpg gain or so...

do you change the oil in the hpop? I am doing an oil flush to my hole system. changed the hpop 6 times now and can see it working. went from cranking the engine for 10 sec to now only 3 sec. I have 1 more full flush to go.

Do you get any smoke at all? black or white?

I started losing power and seeing black smoke when I would stomp up a hill. Didn't think anything of it. until my truck couldn't even haul the toy hauler up a hill. It would over heat and smoke like she came straight from hell:evil: didn't seem like an electrical issue, more mechanical. So I unhooked the clamp that connects the turbo and the down pipe and discovered the engine warm up valve and had been sticking half closed until it finally shut completely. (like driving your truck with the exhaust brake on all the time except worse) replaced the valve and walla:jump: she ran like new.

Another thing is if your seeing loss of power and possibly white smoke it could be your fuel pump and or connection. Had a 02 7.3l service truck started losing power and eventually started pouring white smoke and lost all power. discovered that the connection at the rail mounted fuel pump (between the driver side front and rear door in most cases) there is a black 4 pin connector (only two pins should be in use) that corroded causing a bad connection. Attachment 38045
Attachment 38046

From what your saying, it doesn't seem like this is your problem but I thought I'd better throw it out there just in case.

I wish people understood how completly wastefull it is to "change" the HPO...

Every time you step on the accelorator you have just changed the HPO.

http://inlinethumb15.webshots.com/52...600x600Q85.jpg

Notice the path of oil flow... From the pan to the pump to the HPOP to the injectors to the pan... Nice little change there...

Anyone ever heard of measuring the injector selenoid armeture distance with a feeler guage? Thats what my local shop (hypermax) said to do to determine if they are good/bad or rebuildable. Figured if I do o-rings wouldnt hurt to have the injectors flow tested and cleaned/repaired if possible while they are out. Any other thoughts here?

Anyone have any other ideas??? Ran my truck about 400 miles over the weekend (mostly highway) and averaged 14.9 mpg. 14.9-15 use to be my around town avg. And around 20 hwy...Anyone have the rifraff frx? Likes, dislikes, improvements?

Clays stuff is good, however its not going to improve your MPG... If your close to hypermax just take your injectors there and have them go thru them.

Well, that was my plan but hypermax wants like $560 to go through a set of injectors plus any parts needed...that sound high? I thought swamps and other places were around $250-350 plus parts?

Thank you CSIPSD. That is what I thought but the reading I have done said different.(did not make sence that it would not circulate) Thia is why I like this site!!

Any other ideas on this? Here are some datastream items from my scan tool tonight...this is at op. Temp at idle.
Icp 475 psi
Vol fuel desired 10 mm3
Manifold guage psi 0
MAP 12.2 psi
Ex. Back pressure 18.97
Ipr dc 11%
Ebp reg dc 0%
My questions, are the map sensors on superduties off compared to a mechanical guage? While driving my boost guage to manifold psi on scanner varied by 2-5 psi. Ebp seems high by about 5 psi...should be around 14 psi at idle? Anyone know the boost to backpressure ratio of the stock garret 7.3turbo? CSIPSD, what do you think?

Anyone? Got an update here, last night was dicken around with the truck...sprayed some soap water on my exhaust manifolds at the head...driver rear cylinder bubbles at idle so I do have an exhaust leak there but it is very small. Would that small leak kill my milage and/or power?

Anyone...? Any info, opinions, ideas or answers would be much appreciated!

stupid question but sometimes the smallest stuff makes a huge difference have you checked your fuel filter? ive herd them getting clogged and killing mpg just a thought ?

---AutoMerged DoublePost---

CSIPSD knows his stuff, might want to powerstroke.org there's alot of mechanics on there they might be able to help

Yea, I have probably changed it 2-3 times since this started. Unfortunately with my luck lately its not something that simple :argh: I really wish it was though!

---AutoMerged DoublePost---

Ya he is pretty knowledgeable with powerstrokes. He Has not replied to my post lately....maybe he is stumped as I am:humm: I may post over there someday...

dang hmm i dont know then may have missed this but is the shop stumped? i know my power stroke every time i have a problem with mine and i take it into the shop and it runs fine but when i bring it home it starts up again gota love it sometimes and yeah he does

diesel kleen sucks, it doesnt do a whole lot. im not much a fan of any of the additives except for schaffers, its the ONLY additive i have ever seen do anything for me. it quiets the injectors and ive seen a slight milage increase. if it is getting good airflow in and good airflow out without any excessive smoke it very well could be just fuel ive noticed fuel getting worse and worse, do you fill up the same place every time? do you rotate where you get fuel from?

My guess would be that yea, the shop would say its fine if i took it there but I do all of my own work. Ive asked everyone and theyr brother around here what they think...everyone says injectors. Thats easy to say when its not theyr money, so I figured I would see what kind of answers or help I can get here

diesel 911 kleen works great my buddy pulled his injectors the other day they were clean as new he pulled them a few weeks ago dirty he wanted to see how well that stuff works about a tank later with diesel clean back to normal ,the stuff works great now if you want extra fuel millage there is better diesel fuel additives out there but your going to pay a ton of money for them rev x works well from from what i hear

---AutoMerged DoublePost---

^agreed did you check all of your psi oil psi fuel psi? strange thought it might be the fuel injector pump going i dont think its your injectors

Yes, I have checked the hpop psi and and that is good around 2600 psi at 30% dc if I remember correctly...and ran a mechanical guage on the fuel bowl port and under normal driving load fuel psi stayed steady at 55psi or so...its been a while ago now:humm: diesel kleen seemed to help when I ran it religiously maybe .5 mpg better than without it. For the price I dont think its a bad product. Idk what everyones thoughta are on this but I run Howes lubricator in my 99 in the cold winter months here in the midwest, never had any issues, no gel-up.

---AutoMerged DoublePost---

Moose, I generally only get fuel at one of 2 places. The main place is a truck stop that has reg #2 fuel (not bio blend) its a very high volume fuel station. The other is wal-mart, they have bio blend but its generally really cheap. Either place I fill up I notice no difference. I did fill the truck up at one different station a couple montha ago and same mpg out of that tank as well. I know most of the fuel now days is crap but I dont think that is my issue here...

I like to run redline diesel fule catalist..... makes my daily driver ( 87 idi ) she pulls harder and gets about 1mpg better.... give it a try... cant hurt i guess...... and yes a small exhaust leak can kill some turbo spool and push at rpm..... i work on a lot of lod detroits and newer cummins along with everything in the middle.... slap a set of exh gaskets in.... cheeper than injectors... at this point.. give it a whorrell...... will keep thinking :humm:

Thanks for the reply 4x4. Im leaving for vacation friday and plan to do the exhaust manifolds as soon as I get back next weekend. What are your thoughts as far as just installing gaskets or should I have the manifolds re-surfaced since they are likely warped?

they might be warped a little. probably not bad tho. are you sure it's just not a broken bolt?

Im not positive, the bolts are all still intact but that doesnt mean that they are not broken. I havent had much of a chance to work on it lately but am going to get right on that next weekend. I will let you guys know what I figure out. Any other ideas wouldd be appreciated and thanks to everyone who has replied to my post thus far. Thanks guys!

Hello everyone,
I am a per unit, cost analysis, type of guy.
I bought an $8.00 bottle of Diesel Kleen. It can treat 40 gallons of fuel.
$8.00 divided into 40 gallons equals $0.20 per gallon. THATS twenty cents per gallon added to the already high cost of the fuel. With no better than .5 mpg improvement, does it make sense to spend the extra money for so little benefit. I know the Diesel Kleen can lube and quiet etc...
Just can't get past the fact that the $0.20 is adding to the already high price of diesel fuel.

Thoughts?

have you taken your truck to get it compression tested your truck may be lacking some compression and there may be where your lacking your mpg just a thought. and diesel klean is never bad to put in your truck anything that will clean and lube your motor isn't bad so 20 cents is so worth it in my opinion

I would check your ebpv to make sure its not sticking. I would also leave it unplugged for now.
I replaced my ipr and gained mileage back; I would suggest replacing it. I had good readings on AE but replaced it anyway with best improvements. I also replaced icp because it had some oil in it but I do not think that did anything.

What Cps are you using? If you do not have the good black one; I highly recommend the BWD or Delphi; much better than ford.

Also make sure you fix any boost/ exhaust leaks. Intake plenums are known to leak. I had my exhaust manifolds resurfaced but still had to use gaskets. No improvements fixing exhaust leaks for me.

Good luck.