02 7.3 Towing Not So Good
 

Hey so im new to the diesel world + this site and need some help....
I just bought a 2002 7.3 F350 4x4 crewcab long bed 93*** miles and its a big upgrade from a 150 for towing but i just towed my fork lift (6000lbs + trailer 1200lbs) to a job site and i was not so happy with it. I was cruzin at 55 then hit a little hill and dropped to 40mph real quick then pretty much had to floor it to keep the 40 goin. Then i got to the job and it was a pretty steep hil but not to crazy and going up was a strugle (15-20mph at 2900rpm) I expected the truck to pull the weight way better??? has any one had any problem like this? little more detail the truck is lifted on 35" tires with a 3:73 gear thought it could lose some low end grunt but lose all of it i would hope not. I read some people tow their 40' 5th wheels on 37" tires and 3:73 gears no prob so figured mine would be ok. I didnt have a boost gauge so i dont know what the boost was but now i got one and with no load i see 19lbs dont know if it matters but mor info the better. NEW cam position sensor NEW ICP and NEW IPR valve so what could caust the truck to tow so poorly?

please help ant leads would be somewhere to start thanks

on your truck i think you should be seeing more in the 20's for boost. and 37's for towing? come on lol and with 373's but still i think you're boost is low

If i unplug the wastegate red vac line i make a good 25lbs but with it all hooked 19 is max and 35" tires is what i got i thought of going to a 4:10 or 4:30 but to me it feels more of a motor prob or something not working right. i would thing 3:73 would get ther just little slower but it aint gettin there:humm:

have you towed at 25lbs boost?

no

my 6.9 n/a did better than that in the p.a. hills so theres deffinitely something wrong.

where to start tho what goes wrong with these truck to act like this :argh:

well there could be a boost leak but usually that causes you to build very low boost. is it very cold where you are? when was the oil changed what oil is in it? it's always a good idea when you get a new vehicle to change all fluids

Your boost is normal. Stock is around 17 or 18. Start with the basics. Change oil and fuel filter. Also where are you located? If you dont let these things warm up when its cold out they are ball less till the oil heats up.

i changed the oil and filter 15-40 about 1500 miles ago and changed the fuel filter B4 i changed the IPR valve about 1000 miles ago.... live in California so the waether has been between the 70-50 degrees so i dont thins thats the prob

dam everything is right. do you have any codes or is the exhaust white or hazey?

i did have a waste gate gode b4 but my scan tool got stolen so im not sure... i had the code when my IPR valve was giving me crap and ever sine i changed the CEL has not been back and i have never noticed white or hazey exhaust. it always seem really clear no black no nothin

hmmm, it sounds gutless as hell but everything sounds like it right.... when mine was stock years ago i could tow our gooseneck trailer and fork lift up the mountain no problem? and i'm around 7k in elevation.... try throwing a cold air, 4"turbo back exhaust, and a 6 position chip w/custom tunes on it, that should be plenty of power after that

Air and exhaust will definately help. Most vendors dealing with a 6-POS chip have a veriety of tow settings too, look into it if you go that route. I rarely tow anything but I had one put on...never know when the wife may say "F**k it, go buy the boat you want." :yeah:

i hate to tell you guys this but i got cold air intake straight pipe 3.5 (no muffler) havent got the 4" (YET)

There is no point in throwing power at it if its not running right stock

thats kinda what i am thinking i dont want to put a bunch of performance to it and it cost big. everyone always said the 7.3 is a super strong powerful truck thats y i got it but mine but mine is a dog and i hope its some thing easy haha what what else could it be... 2002 F350 XLT 4x4 cold intake exhaust straight pipe NEW CPS IPR oil changed fuel filter changed ran injecter cleaner through it. Could it be the turbo impeller? wastegate? something eletronic:argh:

Need to get a scan on it. Find out what the ICP pressures are and duty cycles are when cruising down the road.

Also do a cylinder contribution test.

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My Wifes EX, also on 37's and 3.73's... Intake, exhaust, chip and a 38r with a 1.15 housing...

No issues towing with 37's and stock gears...

truck has 35" tires (not a big difference)i bought the truck as is and am thinking about a 4:10 or a 4:30 but there still sould be a little more power there. If i unplug the waste gate vac line i make 25LBS of boost but when plugged in 19 max no more. Also on the ICP it is new it not stock the ICP in spliced in the the wiring y i dont know but it is aftermarket. i ask the guy i bought it from about the truck haing little supdder and he said just use some injecter cleaner and didnt do anything. by lookin at things the guy i bought it from addressed the problem (spuddering) but never fixed it. i fixed it by replacing the IPR VALVE

Sounds like some kind of ICP/10k/18k type mod... Pull it out for now. Go ahead and unplug the wastegate for now, it should pick up a bit of power.

You should have no issues towing those loads on 35's and you DO NOT want to go any bigger then 4.10's. I really dont think you would see anymore power and only worse mileage.

Again, need to get it scanned while driving to really get some good info. Might keep your eye out for a cheap superchips tuner to run or hit up one of our sponsers for a good chip.

Do you have a EGT gauge as well as a boost gauge?

so leave the 3:73's in there? and what about SCT i wanted to try them out... if anyone has personal experience with SCT let me know or anything that will get good power and MPG's i get pretty much 12 MPG no matter what

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oh yah i have an EGT and Boost gauge

A SCT tuner is fine, I would rather have a chip then any flash type tuner on a 7.3, chips give you more options then a flash tuner does.

What are your EGT's when pulling heavy?

Where is your EGT probe installed at?

Re: 02 7.3 Towing Not So Good
 

Drop the SCT and get a 6pos Chip

Sent from my DROID2

a 6 pos. will be better you can switch tunes on the go, but if you only want one tune on the truck and know you don't and or wont change it often, an sct would be fine

So I bought another scan tool and had a code wastegate performance somethin. So took off wastegate tightened it up and got some powerbac:c:k and it hits 24lbs boost so problem solved. Thanks to everyone for ur help but if ur truck ever becomes a slow powerless dog check ur wastegate

from some of the truck i play with depending on year

if the waste gate is not working proberly you could have power loss

or if the waste gate is not set properly

and there is a tube under the turbo on the earlier 7.3 that will have blow by and that will

cause all sorts of power loss

the other problem there could be is you are running over size tires and if your speed has not been recalibrated it can send the computer awire on the late 7.3 they need all the sensors working proparly or your turbo may spool at a higher rpm and make it harder to mantain a speed with a load and or it could be fueling wrong if speed sensor is not right

these would be what i check first

i have had all the problems above and much more that cause power loss